Thank you for the opportunity to share with you today our work at George Washington University. We'd like to tell you about a library ecosystem which is developed organically since we first shared this work with CNI in 2013. This program may be unique in certain ways and it's serving as a rich source of research data for researchers not only at our institution but beyond as well. My name is Laura Rubel and I'm a software development librarian and I'm joined by my colleague Dan Kirschner. Hi I'm Dan and I am a software developer and librarian as well at GW Libraries. As Laura mentioned, we first presented this work to you at CNI seven and a half years ago actually and a lot has happened since then. What now is an entire suite of resources systems and services at GW Libraries began initially as a small tool to help a faculty member avoid manually having to cut and paste tweets from the Twitter web interface. So as word spread, we began helping other researchers at GW, and the more that the word spread, we realized that we needed to be better able to scale the service we were providing to help collect data on behalf of researchers so with the help of grants from NLS, NHPRC, and the Council on East Asian Libraries, we rebuilt the social fee manager tool with more of a self service interface. Now, several years later, we've realized that we needed to add consultations to help each new researcher refine their research question, learn how to use our systems and refine their data collection strategy. We've added recurring workshops about collecting and working with social feed social media data. And, in fact, as we will show you some of our work with faculty and students has led to more in depth research consultations and even external collaborations. Finally, we realized that we needed another system to facilitate access to and subset data sets that we've already collected. And so we have now tweet sets for that. And we've taken some of those data sets and publish them on Dataverse. So another view of our whole ecosystem, which by the way also includes the ability to collect from a few other platforms Tumblr, Flickr and Cina Webo. And here are some researchers. And we're going to describe now some of the components of this system. So starting with the social feed manager. Social feed manager, we'll call it SFM, is a web application that we created at the beginning of this whole process. This is the more self service version of it to allow users to create data sets. And using the Twitter API but without having to actually do the programming. And we created it for users within our institution. Now here we're looking at a sample view from inside SFM where a user might specify the Twitter accounts hashtags etc that they want to collect from. Where the user can then download the data after it's been collected. So we did develop SFM at GW and we're describing the role it plays in our ecosystem that includes other systems as well for researchers who can get the data and even without using SFM like through tweet sets. But SFM is also for researchers beyond GW as well through the social feed manager, the social media data that is collected using SFM. And in fact, SFM is being run at other institutions. So code for SFM is open source on GitHub, and as other institutions around the world have started to run SFM for their projects. We're actually starting to see code contributions from developers and projects at other institutions. So, to we use two main platforms to facilitate access to data sets that we as librarians have collected and opted to make available. So tweet sets is one of those platforms and it allows users to derive subsets from those data sets that we collected for users on the GW campus network. Tweet sets allows users to download the full data of the those subsets that they would derive so we're looking at images here from a screen where they might select the source data sets that they want to work with and then where they would have parameters for their own subset, perhaps like a date range or matching certain terms, things like that. So users that are not on the GW network can still access this resource, but there would only be able to download the tweet identifier so it's like one identifier for each tweet, and then they would need to use a tool. There are three tools out there to re hydrate the IDs, which means requesting the full data for that corresponds to each tweet identifier from Twitter directly. And Twitter will provide that back to them. If the tweet is still posted. So for a smaller set of our data sets, we've chosen to also publish those data sets on Harvard Dataverse, where again users would only get the identifiers but many people are finding those useful as they go and re hydrate those data sets. So, there's no subsetting available on Harvard data sets, Harvard Dataverse rather, but Dataverse offers present preservation features and also Dataverse generates a DIY digital object identifier, so that if a data set is used in research it can be properly cited and we are in fact seeing citations of our data sets in published research. So these two platforms tweet sets and data verse. We are able to provide access to data sets that we've created and enable them to reach a much wider audience. So now that we understand what role social feed manager plays in doing the actual collection and tweet sets and Harvard Dataverse in facilitating access to those collected data sets. So let's talk about data flow where social feed manager is the the component that's that's interacting directly with Twitter the source of all the data. We as librarians use social feed manager to create collections but as mentioned, we, we have we invite students faculty and researchers within GW to create their own collections on social feed manager, and they can download the data from their collections at that point in the flow. So the collections that we as librarians have collected. We post some of those, the ones that we feel would be of interest on tweet sets where users can derive subsets and if they're on the GW network they can download the full data sets if they're not they can still download the identifiers. From the data sets that we post on tweet sets a subset of those we've chosen to publish on Harvard Dataverse. And of course that's just the identifiers but we get a digital object identifier on there, and we're seeing plenty of public usage and Laura will talk about that more as well. So we meet with each researcher as part of their entry into using social feed manager, if that's what's needed or tweet sets. We conduct workshops, and we've actually been invited to guest lecture several times in GW courses including first year university writing programs on topics like fandom audience in the age of new media. We've spoken to data analytics and text mining courses because they find social media data to be excellent data sets for learning those techniques. We've lectured in political science courses. And of course other services that we provide are helping with research collaborations. So a little bit about the nature of the, the content that we collect. So here you see a variety of topics. We have a, our largest set right now is on the Coronavirus tweets related to that we, we make a point of consistently collecting from major elections in the US, and government accounts, something that is sort of an emphasis at GW being in DC. Events such as hurricanes, and, and other events that we've found to be of interest to our researchers. Now, there are more sets that you can view on the tweet sets application which will have a link at the end. And this is only what we as librarians have chosen to collect the, we have a very thorough list of all of the different topics that our students and faculty and researchers just at GW are collecting and it's quite diverse. To get a picture of the usage of social feed manager and our data sets and, and how they've been used we've been tracking usage with several approaches. We keep a running spreadsheet of GW SFM usage. And we're seeing usage across campus departments from business international affairs computer science, religion, even the med school. So we know we're reaching campus broadly across disciplines. This tracking of support and interactions also helps us share support responsibilities as a team. So this is a screenshot from tweet sets and tweet sets keeps statistics about the source data sets downloaded and the data set format so whether it was a CSV or tweet IDs, and also by on campus network versus non GW users. Some of the data sets that have been the most popular are the news outlets data set coronavirus data set and climate change tweets as well as numerous elections data sets. And we've recently added Google analytics to tweet sets to get a better sense of how people are finding it and where they are in the world. This is an example of one of our data sets up on the dataverse platform the data repository where we've posted to the ID data sets and it automatically collects usage, just download usage statistics, which is helpful at a high level and understanding reach. So, while we don't have any more detailed usage from dataverse, we do get roughly weekly emails from someone who's come across the data sets and has a follow up question. Sometimes they're requesting access to the full tweets which we can't share under Twitter terms of service, but other times the questions are about the collection criteria, the collecting process or gaps in the data, wondering when we might be next updating the data sets. So we have a lot of this kind of information in the data set description data set users often want some further context. We've heard mostly from grad students and faculty from around the world. So Netherlands, Germany, South Korea, Australia. The point I want to make is that posting data sets is not the end of the process you should expect to provide further support and communication. What's particularly interesting is tracking how the data sets support published research. So these are some example citations for some recent research published by GW faculty or researchers. Sometimes we hear directly from GW researchers that they've been successful in their work, getting it published other times we come across the research much later after our interaction, as their work has made it through that publication pipeline. So for example, citations of work by researchers beyond GW who use one or more of the data sets we posted. Because we don't usually hear from those beyond GW, making use of Dataverse or Tweetsets data sets we monitor for publications that mention our site or data sets so we have a few Google alerts going on some relevant keywords, and also periodically do some database searching. And this is all fed into a group Zotero library. It's probably where the researchers aren't always consistent in how they cite data sets. And so this kind of tracking has a manual aspects to it and does require some time and effort. However understanding the reach of SFM and our data sets helps us and our leadership being formed as we discuss this program and decide what resources to put toward it. So this is off in being able to have a better understanding of where topical interest in the data sets is and what we might collect in the future. Finally, it also makes the point that this data is proving to be reusable. We know that it's being adopted by researchers here at our institution and worldwide. So as we meet with most users of social feed and a jar we get to participate in their initial planning of their project. So we're supporting researchers early in their work as they're considering where and how to get their data. As they're thinking about which research questions they might pursue and and how they might do their analysis. While some of the faculty who use SFM are experienced social media researchers others are new to working with Twitter data. So they may find SFM useful for exploratory research, trying out methods and data that are that are newer to them. Students who are looking for social media data are often working on capstone papers or dissertations or undergrad honors thesis so they're digging into this data for often a multi semester project and and learning some new methods as well. So it's great to position the library early in this process. It's also open the door to participating more deeply in research on campus. So as an example, Dan has been involved in work to analyze each and tweets by candidates for US Congress. I'd like to analyze the claim that COVID-19 was a misinfo DEMEC by looking at URLs in tweets about COVID. So he facilitated data workflow around this large data set collaborated on data analysis coding in our and Python, including the data visualizations and was a co author on paper. I've also been part of conversations and work by the program on extremism and the Institute for data democracy and politics here at GW. I was recently involved in helping an American studies professor track the origin of a Facebook meme that you see on the left there relevant to the argument of her paper. She connected up with the library because of our social media consultation service. I worked with her to use reverse image search web archives and social feed manager to confirm some tumbler metadata around the meme. So it turns out the origin of this meme was tumbler not Facebook. And the faculty member was then able to speak to the woman who originally created the meme and interviewer about it. So it was a really interesting research support activity that came out of our involvement in this space. There's a broader social media data community that includes librarians archivists developers and social media researchers are developing some expertise in the library in this area has also provided an opportunity to share with that professional community beyond GW. We've provided workshops through the IMLS Laura Bush 21 funded project said work or continuing education to advance web archiving and given some webinars for the digital preservation coalition in the UK. The archives on leash project is doing amazing work to develop platforms and educational resources for web archives users. And we've contributed some data sets to past data thons that they've run. This talk now community is made up of people from all facets of social media archiving and research. They're doing great work leading development of software and other resources to support ethical approaches to this work. So providing both the tools to collect social media data and the services to help users be successful working with the data has led to some benefits to campus researchers in the library. So for researchers, most obviously they get the data they need for research questions from a range of disciplines. They get access to otherwise unavailable free historical data. We're opening up access to data to users of all technical backgrounds. So regardless of the role of their university whether at the university whether their first years grad students or faculty SFM and tweets that help them get data from from these students get this hands on experience learning about data collection considerations and faculty now have data sets easily available for teaching data skills to students. And then finally faculty can move into research areas that may otherwise have been difficult to pursue. For the library. This work really positions the library in a unique way in the university environment as a data creator and as a data publisher. So we're modeling good practices around publishing data that is well documented and supports reproducibility and other fair principles. And the data is findable accessible and in common formats expected by researchers such as CSV. We're leading in collecting data sets of cultural value as events of significance occur whether it's an election or a natural disaster or a campus event and archivist and special collection librarians are key partners in this work. Social media data comes with important privacy and ethical considerations, and we embed these concerns in our conversations with students and faculty. So the library becomes part of this conversation on campus around data ethics and privacy. Librarians and developers get firsthand experience and involvement with research support using larger data sets and helping the organization build relationships in this area on campus. So this work really can lead to opportunities for library staff to become further or more deeply involved in research projects, support grant funded research on social media data and use our related skills, working with data as partners in these kinds of projects. So this type of work also has its challenges.  And with several other software development projects responsibilities and things like teaching workshops being available for research consultation consultations and other responsibilities. So we find that all the activities that we've described associated with assisting researchers at GW with using SFM tweet sets, and then of course the data itself that they get through those systems takes time and effort not to mention that we receive those inquiries from external researchers about our data sets and about the software. And although the bulk of our time is as it probably should be focused on serving our immediate community of GW researchers. It's still quite time intensive. So, if you go to our GitHub repositories for SFM and for tweet sets, you'll see that we have plenty of tickets for feature enhancements fixes and other issues. And maintenance may not be flashy. And it takes time and dedication, but it's an ongoing necessary investment for us to be able to continue to provide the support and data to the many researchers who depend on us with not only the software men maintenance but especially with the services we provide, ensuring that time and tail they're both visible and measurable can be difficult. We spend considerable time as Laura described keeping records of exactly who we help and with what project, but even that's more of a list and still hard to quantify in terms of the hours spent providing that value. So, Laura also described what we do to try to capture the end effect and impact of our assistance in terms of research output. But many of the projects that we support don't ultimately turn into publications that we can cite, but we still contributed to the education of the students that we work with. Although we for our part as data providers do our best to educate the users, at least the ones that were in contact with about appropriate use of social media data. We've still had to ensure that the overall activity of providing the service and collecting the social media data sets is something that our institution is comfortable with from a legal and policy standpoint given the privacy issues involved inherent to the social media data. So the, another consideration is the fact that the Twitter API is evolving. So that evolution provides both opportunities with any new affordances that are coming out. But also, we have to keep up with changes that might impact the parts of the API that we're already using. And then an important consideration is the fact that tweet sets itself with its ability to for a user to generate custom subsets of each data set can be quite computationally intensive. The data sets are very large and generating subsets from each one can can take hours or in some cases even a day or two so we've made some improvements, but we're providing that as a public service that reaches even beyond GW. And we need to balance, of course, the value of providing that public consideration with the fact that those it's provided on a limited resource on our infrastructure for free. So, in terms of some some ideas, a few ideas at least for future directions. Especially over the past year we started to really see more interest from software developers from a few other institutions using SFM already propose improvements and submit pull requests for the SFM software, and some of them have expressed their willingness to participate in a potential community software development sprint. And that's part of sprints like that for other open source software. And we feel that that model where other adopters of SFM in this case are truly stakeholders might be a good way to improve the long term sustainability of the software that really is the the workhorse in terms of collecting the data that flows through and forms the substance of all the other services and research output that we enable. So, another, another potential idea that we've had is as a library. We're starting to think from an archival perspective about perhaps accessioning some of these data sets, and maybe including them on our archive space instance, and really viewing them in that way. So, last but not least, we would encourage you to reach out with any thoughts questions ideas that you have we have an email address for this project it's SFM at GW.edu. And the two main links we'd like to leave you with our the link to our social feed manager project it's not the software itself but it's everything about the project. So if you can view and even download some of the data that we've posted tweet sets. Thanks for the opportunity to speak with you, and we hope to see you in person at future CNIs.


So, one will come to the 30th session of the second module in the core signals and systems. We shall continue in this session to build up on the properties of the Fourier transform. We had seen one property, a very important property of the Fourier transform in the previous session, namely linearity. So, linearity essentially says that if I take a linear combination of two signals who have a Fourier transform, the Fourier transforms are also linearly combined in the same way. And I had left it for an exercise for you to do to prove the same thing for the inverse Fourier transform.  So, property number 2, time shift, what happens when you shift a signal in time. So, if h of t has a Fourier transform of capital H of omega or capital H of f, remember we are going to talk both the language of angular frequency and in the language of cycles per second frequency. What is the Fourier transform of h t minus tau 0? Of course, tau 0 is a constant. So, this is the question that we ask, very simple. Let us derive it. All that we need to do is to find the Fourier transform h t minus tau 0 e raised to the power minus j omega t dt integrated from minus to plus infinity. Put t minus tau 0 is equal to lambda whereupon t is lambda plus tau 0 and dt is the same as d lambda. And when t runs from minus to plus infinity, lambda also runs from minus to plus infinity. And therefore, this integral simply becomes minus infinity to plus infinity h lambda e raised to the power minus j omega lambda plus t 0 tau 0 d lambda, which you can now separate. So, you can bring e raised to the power minus j omega tau 0 outside and leave the rest inside h lambda e raised to the power minus j omega lambda d lambda. And notice that this is essentially capital H of omega or H of f, whatever you like to call it. And therefore, the Fourier transform of h of t minus tau 0 is e raised to the power minus j omega tau 0 times h of omega or in the language of f, e raised to the power minus j 2 pi f tau 0 h of f. So, essentially the magnitude mod h omega is the same as the magnitude e raised to the power minus j omega tau 0 times h omega. The magnitude is unchanged and the role played by this quantity, this multiplying factor. This adds a phase of 2 pi f tau 0 or omega tau 0 to the Fourier transform. So, it is very interesting. When you shift a function in time, the magnitude of the Fourier transform is unchanged. What changes is the angle or the phase of the Fourier transform. And in fact, let us plot the change of phase of the Fourier transform as a function of the angular frequency, which sets a very interesting idea that we will see now. So, we will notice that the change of phase as a function of omega is essentially omega tau 0. In fact, minus omega tau 0 to be precise. So, it is a straight line passing through the origin with a slope of minus tau 0. This is what is called linear phase or linear phase change. This is very interesting. So, when the change of phase as a function of frequency is linear in frequency, the implication is that the signal is shifted. Now, let us understand this change of frequency being linear. What is the physical meaning of the same? Let us take a single sine wave and let us see what happens when we shift at all frequencies by the same tau 0. Let us take one sine wave first.  Let us make it a 0 and let us shift this by tau 0. So, it becomes a 0 cos omega 0 t minus tau 0 plus phi 0. Now, we can identify the change of phase here. So, I rewrite this as a 0 cos omega 0 t plus phi 0 minus omega 0 tau 0 and pull out this part as a change of phase. The change of phase is minus omega 0 tau 0. As you notice, this change of phase is linear in frequency omega 0. So, if I want all frequencies to be shifted by the same time, I need a phase change which is proportional to the frequency. That is why linear phase has an association with shifting the entire signal by the same time shift. Now, I emphasize this point so much because linear phase is something that we keep yearning for. You will hear this term if you go ahead in designing systems, particularly filters. If you talk about channels, if you talk about systems for communication, for control, whatever it is, you will often hear the term linear phase. And right at this point, you should be clear why people are so fond of linear phase. Linear phase has the interpretation of shifting all sine waves by the same time shift. Now, visualize a situation in which you have a signal comprised of many sine waves and if you want to shift the signal in time, of course, all these sine waves should be shifted by the same time. That means, the phase changes should be proportional to the frequency. If they are not, then different sine waves should be shifted by different amounts in time and then you have a phenomenon called dispersion. So, let us write that down. So, if for whatever reason the phase change is not linear in omega, we get a phenomenon called dispersion. Different sine wave components are shifted by different times. Now, dispersion is a term that you will often hear, for example, when signals are transmitted on optical fibers or on other communication media. Actually, dispersion is a suggestive word. You know, typically what happens is you have reasonably narrow pulse and you know what kind of sine waves come together to form pulse. We saw that in a previous session where you made a decomposition of a rectangular pulse into its Fourier transform. In fact, it has frequencies of all magnitudes and signs. That is what we realized, except for certain nulls and now if you subject this pulse to a system which does not have a linear phase character whose frequency response is not linear in phase, what is going to happen? Different sinusoids which come together to form the pulse are going to be shifted by different times. So, the pulse spreads effectively. That is why it is called dispersion. Anyway, you will hear this term. For those of you who go further, taking this course into a course on communication systems or a course in wireless communication or mobile communication or control, you will understand better the idea of non-linear phase and linear phase. But I thought it is expedient to explain the importance of this idea of linear phase right at this point in time. Now, let us look at a reversal of roles here and we will take that reversal of roles further in a subsequent session. Now, here you have multiplied the Fourier transform by a phase changing term e raised to the power minus j omega tau naught. Suppose, we reverse the roles of time and frequency. So, we multiply the time function by a rotating complex number. Let us see what happens. In fact, we will give it a name. We are now going to look at the next property. That means, where we modulate. So, let us multiply h t by e raised to the power j omega naught t. Omega naught is a constant and of course, real. And let us query what is its Fourier transform given that h t has a Fourier transform of capital and h omega. The answer is very simple. Indeed, integrate from minus to plus infinity e raised to the power j omega naught t times h t e raised to the power minus j omega t dt. And very easily you see that this is essentially h t e raised to the power minus j omega minus omega naught t dt which is simply h omega minus omega naught. And there you are. We have the answer. So, it is very interesting. When we modulate, modulate means we multiply h t by a rotating complex number rotating with an angular velocity of omega naught. The Fourier transform is shifted by omega naught forward. Now, of course, omega naught could be positive or omega naught could be negative. In either case, the principle is the same. If omega naught is positive, then indeed we are shifting the Fourier transform forward by omega naught. If omega naught is negative, then we are in principle shifting the Fourier transform backward by mod omega naught. Simple. In any case, we are shifting. Now, you know, you are beginning to notice something interesting here. I have a property, property 2 which talks about what happens when I shift a function in time. It causes a modulation in the frequency domain. You know, you remember it multiplied the Fourier transform by a term e raised to the power j omega tau naught. When I reverse the roles of time and frequency, the consequences also are reversed. That is interesting. So, I modulate the function in time by rotating complex number and the corresponding Fourier transform is shifted in frequency. Shift in time becomes modulation in frequency. Modulation in time becomes a shift in frequency. We are beginning to see something interesting here. And we make that formal in one of the subsequent sessions. It is a very beautiful property of the Fourier transform. We shall see more properties of the Fourier transform in the sessions to come. Thank you.


Hi there! It's DJB and in this video I'm going to be talking about what to purchase as your first airbrush. So I always wanted to purchase an airbrush and there really wasn't any information on what to get as your first airbrush and a straightforward beginner's guide into airbrushing. So that's what this video is going to be. I personally use my airbrush for model courses and that is what this channel is dedicated to. I paint models both big and small. I love the airbrush and using it as a tool. That is the first question you must ask yourself when purchasing an airbrush. What are you going to be using the airbrush for? I know some artists do their work primarily on paper. War figurines, video game figurines, model horses is a big community. There's a variety of things that you can use the airbrush for but generally speaking it's used for models and it's really good for models because you can get into all of the weird areas that you wouldn't be able to with a paintbrush and it's the same acrylic paint that dries quickly and doesn't smell bad but you're able to apply it in a really smooth way that gives an awesome appeal to your finished model. Depending how much you're going to use the airbrush contributes into what airbrush you should get. If you're going to use the airbrush just a few times then maybe you don't need something as high quality. If you're going to plan on using the airbrush to sell artwork I recommend getting a higher model. It depends what your use is going to be for. There's also a variation in whether or not you're going to be painting really small items or really large items. There's different spray levels for certain airbrushes. I personally have this Iwata Eclipse HPCS and this is a pretty general airbrush for most artists and there will be a link in the description to purchase this airbrush. It runs a 35 millimeter needle and this particular one I have is gravity fed and it has the large cup. This brush will last me a lifetime. I will never grow out of this brush. I will only add brushes to my collection so when you go with a good quality middle of the road brush you can have the potential to upgrade but you won't feel like you need to upgrade. You feel like this brush will do what you needed to do and I would highly recommend this as your first airbrush for the price point and what it can do. Now Iwata is industry standard so Iwata is the name of the airbrush. They've been doing it for years. They figured it out. They know what's what. These brushes are built to last. They come with a warranty on them. All of the parts you can get replacement bits for them. They're used on shows like Face Off and Paint Wars. It's like anybody who's anybody who airbrushes has heard of Iwata. Now I have heard success stories with badger brands. I firstly have never tried them. Their brushes are a similar price point if not a little bit lower and you can get replacement parts for those as well. Now that being said this eclipse is kind of that middle of the road. They also have the Iwata Neo which I've read good things about. It's about an 80 dollar brush. You can get a cheap little compressor that goes with it. Not too bad of a brush and then you get into the really fancy ones that are on the higher end of the spectrum like the Micron. So there's also a couple different styles of airbrush. So this particular one is a gravity fed but you can get a couple different styles. So this is the large cup gravity fed airbrush. So the cup is quite large. It can hold quite a bit of paint. It comes with a lid and so you can lock the paint in and you can use that much paint in your airbrush and the gravity just pushes it into the nozzle so that it can spray out. There's other types that come with smaller tops depending on how much paint you're going to use. The bigger one is better I find. You can tip it and you're not going to worry that the paint is going to overflow and spill everywhere. You can also get ones that are bottle fed. They come with a full bottle on the bottom. You can get ones that feeding from the side. Don't really know the specs on these. I've heard gravity fed is the one you go. You end up with less clogs, less issues, your pressure doesn't need to be so dramatic. So you will see airbrushes that are labeled as dual action or single action. Single action means that you literally just pull the nozzle back and you get paint and pressure. That's all there is. That's all the range you get. It's either on or off. Dual action means I can push down for air, pull back for paint. So dual action basically means that you have more control. So I can control the amount of air that's coming and the amount of paint that's coming. And so I find this really important because you have way more control and you can create better techniques and effects this way. A lot of people think that airbrushing is super messy. It's not. I don't have any issues with this spraying anywhere it shouldn't. I do have a sheet up against my wall to protect my wall but I've never had any problems where I've had to like really make sure that that was up. You can get away with just a cardboard box but you really don't even need anything. For the miniatures that I paint, the airbrush really doesn't have any overspray so I've never run into an issue with that. I would recommend airbrushing somewhere with ventilation or at least a little bit of airflow. What comes with airbrushing is that you do need a compressor. Airbrushes run on compressed air. They're pushing paint through to create a very fine mist and for this you need an air compressor. You just need a hobby air compressor. I personally have a compressor that I just got off Amazon. It's nothing fancy. I know Iwata and Badger and I think Apache all make airbrush compressors to go with their airbrushes. These are really expensive and I think really overkill because I was just getting into airbrushing I didn't want to spend a whole bunch of money so I went on Amazon and for about $130 I got myself a good little compressor. I've had no issues with it. It's just under two years old now and it's been going strong. No problems. The things you want to look for in your compressors are the same. There's two different types. There's a compressor that you will turn on and it will run the entire time and there's a compressor that comes with an air tank. Mine comes with an air tank so it has a three liter tank and so that means that when you turn the compressor on it's not going to be running the whole time.  So when I'm painting with this air compressor if as long as I'm spraying it's pretty much running the point is when I need to change paint or if I'm not doing as much it will shut off so it's a little bit quieter. So I would recommend getting that air tank. It's a little bit more but it definitely helps and it helps the air compressor itself because it can get quite hot and so if it has a break every once in a while it doesn't have to feel like it needs to run the whole time and that way you don't have to worry about turning it off and forgetting about it and having too much pressure or whatever it is. I also think that having a tank adds consistency to your air pressure and your air flow because there's already a reservoir it doesn't need to continuously like pumping in the exact right amount of pressure. This compressor also comes with a pressure gauge that's really important because you can change the amount of psi that's coming out and the amount of psi is going to change the amount of air flow that's coming out of the airbrush. So this varies for what you're painting and depending on detail or widespread work the psi is going to change the flow of your airbrush and another good feature to have is a moisture trap.  My compressor also came with its own cord so that's also something to look into and make sure that it has the right adapting heads on both of it. There's a couple other things that come with owning an airbrush so the airbrush itself the compressor that we talked about somewhere to paint but then there's just a couple little must haves that also come with owning an airbrush because there's maintenance on an airbrush for both yourself and the brush. The number one thing you must buy with your airbrush is a cleaning pot.  You need to clean out your airbrush every color you use and all the time constantly and this makes it completely simple so this is just a cheap off-amazon cleaning pot like will be in the description below.  Twist it off and you can clean it out when it's two full like right now. You're also going to need a airbrush type cleaner. This is a necessity to owning the airbrush. You have to clean it out between paints. This is a water-based cleaner but it has properties in it that help break up the paint. Media Iwata airbrush cleaner. Fast-acting odorless and environmentally safe. There are more advanced ways of cleaning but I'll get into that in a separate video about how to clean your airbrush. There's a couple different kinds of paints that you can get for airbrush. There are paints that are designed specifically for the airbrush. I personally have used both Golden High Flow Acrylic and Vallejo Model Air. These both work great. They're paints that are designed to go straight into the airbrush. There's also paints such as Createx. There's a lot of different brands out there but there's specific airbrush paints that are designed to go right into the airbrush. I would recommend buying these paints versus mixing acrylic with water or a reducer or anything like that because they just work better. They flow out of the airbrush better. You'll be less likely to have clogs. You'll be more consistent in your color, your texture and your flow. You want to protect yourself when using these paints. A lot of the products that I've used directly say on them can cause cancer or bad fumes. Don't inhale. So getting one of these respirators is a really good idea and I wear this now every time I airbrush because the smell of the paint sometimes isn't great. It's not good for your lungs. It can cause cancer. So using a respirator when you're airbrushing is really important. So these are the correct filters that you should be using on your respirator. They are the 3M60921 designed specifically for vapors so they trap all of the particles that comes from using aerosols and paints. Highly recommend this. I have a whole video on it as well so I'll put the link to that in the description. So with my glass pot it also came with these funky cleaners. I don't find these super necessary but they are good to have on hand in case something goes wrong. They came with my cleaning pot so I'll link that in the description. My Iwana airbrush came with both a wrench and some lube but these are also important to have on hand. It's literally a lube designed for the airbrush. You can drop it in the room tomorrow and make sure everything's running good. And then this wrench is to take the airbrush apart. The last important tool that you should get is the Iwana nozzle wrench. Airbrushes frequently need to be taken apart and cleaned and you have to replace parts at times and this is a tool that will take off the nozzle safely so that you won't destroy it and wreck your airbrush. So it's a really important tool. It's a good idea to get some replacement parts, have replacement bits on hand. I always keep a replacement needle and a replacement nozzle in my studio because you never know when it's going to break down. So I hope that this helped make your decision a little bit easier and guided you in the right direction of what you're looking for. This whole airbrush escapade cost me around $400 all said and done. I made that back in probably the first month of owning it so it wasn't a huge investment for me but I would highly recommend just doing it even if you're just doing it for fun. It's a super fun tool. It's super rewarding. The level of work I've been able to get out of this airbrush I never would have been able to with another medium so it's really really fun. I would highly recommend it. I love airbrush.  I hope this helped. If you have any other questions feel free to message me. You can leave a comment below. Let me know what your concern is, your questions and I will try and help you out for sure. Thank you so much for watching and happy airbrushing. All of the tools used in this video are in the description below. Please subscribe for weekly Wednesday uploads. Follow me on Instagram and Facebook at DJB Studios. Check out my website and sign up to my mailing list to be the first to know about commissions, tutorials, and sales pieces. If you have any questions feel free to message me.