SIde note on peltier devices (thermoelectric modules/coolers): The stacking capacity is limited, notice how each TEC in the image at 12:20 has smaller and smaller TECs. The first is causing a thermal gradient, effectively moving its heat from one side to the other using power, cooling the sensor. The second one is doing the same, however it also has to move its own heat plus the heat load of the first. The third therefore is moving its own, plus the second, plus the first. A common mistake is to stack the same size modules, and while this will work in some applications, it doesnt quite provide 'twice the cooling' one would expect and its very easy to overlook how electrical power and heat energy move and stack through TECs leading to burning out the modules by overloading them. The long skinny is they're not magic, and do your homework. So long as you dont treat them like magic cold makers you should be golden ;)
I think this project is ahead of its time currently. It is clear only to a small amount of people that you can do better science by knowing your device inside an out. Do you think Im wrong here?
It is not ahead of time, it is the right frontier effort to get things moving. There is much more information in public domain to expand it features and performance wise, to the point of making it viable replacement of commercial systems.
I'm sometime confuse about the PUMA main goals... In one hand, it seem to aim to make science more affordable worldwide. For example, the basic microscope that don't use electricity, only a simple mirror like in the old days (including my old days!). But on the other hand, like in this video, it seem like the only 'sensor version' is prohibitory expensive and any cheaper alternatives are not viable/possible. Off course the proper expensive camera will get better results, but is there a way to offer the phone camera sensor as a genuine alternative? I've went to Haiti to offer free training to University students. They have very limited access to electricity (solar), internet, computer and of course no money. However, despite having no money and almost no access to electricity, all of them had their personal phone (with camera). My whole point: Is there an option to use their cheap phone as a microscope sensor? Or the only viable option is without sensor? It could cut some cost down by removing the eyepiece as well. I did not watch all your video, I might be totally wrong with my assumptions. In all case, you have no idea how I appreciate your tremendous work and dedication to the humble science.
There are two prime goals of PUMA: 1. Free education about how microscopes work and 2. Providing people with the knowledge means to make their own affordable yet high end / professional standard customisable microscope. 'Affordable' is relative to the level of sophistication (e.g. what is affordable for a basic manual viewing scope in ordinary transillumination will be different for what is affordable for a fully robotic motorised epi-fluorescence microscope with multiple camera outputs). The PUMA system - with its modular approach - allows both these systems to be made but obviously one will cost more than the other to build DIY but in both cases it will be orders of magnitude cheaper than buying the equivalent functionality microscopy from a big microscope company. Regarding cameras the choice is up to you. You can use professional standard cameras like the ones shown in this video or you can use a cheap camera costing about £5 or you can use your smart phone for sure - you might need to modify some of the 3D prints to fit a smart phone to a PUMA without an eyepiece but it is definitely possible. There may not be a model or module to fit your particular smart phone but that is why I make PUMA schematics freely available to anyone in FreeCAD editable format - so you can tweak the design to suit whatever apparatus you happen to have lying around. The 'cost' in this case is not money but your time and hard work in learning what needs to be done and then doing it.
@@PUMAMicroscope Ok, it is exactly what I taught about PUMA noble goals and I love it as you know! Maybe it was my feeling about this video, I had a vibe that cheap camera was not an option at all. Many disadvantages on cheap camera, but without saying that you still can use it and get 'better than nothing' usable image. It would be very nice to see more comparison between cheap DIY/expensive DIY/High end microscope options with price, benefits/limitations and side by side image quality. For example, you discuss about the limitation of the cheap sensor, but we only see a blue square. A direct comparison would be more self explanatory I think. It might be enough quality to go that route or it might be an obvious waste of ressources. When you are in a very tight budget, testing non-viable options that require buying parts is a risky business. Wasting time is not a problem, it's learning. Wasting money on the wrong (too low/high quality) piece of equipment is the big issue. I really appreciate the fact that the designs are truly open source (free and 100% customizable). I have not seen the files yet (I do have a 3D printer, so I will). It would be great if people could contribute more to this project. Maybe use PUMA_Microscope as a reference word within Thingiverse? I invite you to do a collaborative video with other YT like MicrobeHunter and others. Not only asking people to take your designs, but also improve them and share their work. You are working so hard and producing top level quality; we should spread the words. And theses YT in microscopy are very willing to share that precious knowledge. You can also reach the YT in 3D Printing; they have the same vibe and huge community waiting for cool projects to contribute. Thank you for your time. We are blessed to have people like you in this Universe. Love from Montréal
This particular video is about education in quantitative scientific image capture - not pretty picture capture for simple illustration. Maybe that is why you got confused? For simple illustration capture you can use cheap cameras without all the features discussed in this video. However, 'cheap' cameras cover a large range - I have tried some cheap cameras that are really no good for anything. Others are OK for simple picture taking but no good for scientific quantitative imaging (like the example shown in this video). [Please note in general: I do not allow comments to have links to other websites in them so if you put a link into any comment it will be automatically rejected and not show up here (even if the website is innocent). This is just a blanket filter I set for anyone posting on my channel.]
@@PUMAMicroscope Your explanation about my confusion is spot on! Back in the time of Julius Richard Petri, scientific was not so picky about what we consider lower resolution in modern standards. As long as you can support your theory, science should not complain. But low res image might make it hard/impossible to support your point! Like a blurred image of UFO/Yeti won't fly high in a serious scientific convention. Sorry about the shared link. I never taught about other malicious person. Next time I will adjust myself. Thanks to let me know about that.
One of the most important microscopy imaging experiments I have ever done involved the used of a 'camera' with only 1 pixel - yes you read that correctly, just 1 pixel (not 1 megapixel, no, just one a single pixel). So, basically it was just a single point light meter - but it gave accurate quantitative photometric results and I got a good scientific image result from it (don't try to understand how - that needs a lot of explaining). So my point it that accurate photometry is much more the important feature of any camera or light sensing device for scientific quantitative phortometric microscopy imaging than resolution - no matter how low. Some experiments do need high spatial resolution as well, others don't - but what is common to all is that they need accurate photometry (which is what this video is about). Some scientific imaging does not even need photometry - it all depends of what is the scientific question being asked (counting objects, for example, does not need quantitative photometry). But again, all of this is completely separate from people who just what to take pretty pictures - that is a whole other field of work and the requirements of a camera will be different for that purpose.
7:09 or 10:16 Stupid/basic question warning: If we get only an infini-corrected objective aligned on an open camera sensor, will it produce a usable image on the surface of such sensor without any additional lens? How wide the image is in mm on the sensor? How wrong I understand it all again!? My goal was to make a slightly cheaper microscope without the eyepiece, without a precise length tube, only objective and phone sensor (with or without the phone's lens in place, whatever is the easiest and the cheapest, or according to the possibles different results). I'm a scientist, but a noob in this field. And to be honest, I've watch many of your video, and sometime I feel stupid! It's like learning a new language with so many unknown words! I Google most of them, but even then, it's not that easy. FYI, I was an analytical instrumentation specialist, mainly in chemistry/pharmaceutical and mining industry. Love from Montréal
You will not get an image with an an infinity-corrected objective because they are designed to emit plane wave fronts when the sample is in focus so you must have some lens after the objective to focus those plane wave fronts into an image on the chip. (You could use an infinity corrected objective in a way is was not designed for in order to get what you want but the image quality will be poor). If this concept of plane wave fronts is not familiar to you, I will be making some videos to explain them some time next year. So, if you want to do this kind of direct-to-chip projection without an eyepiece then what you want is to use a finite tube length objective (not infinity-corrected). This will project an image directly onto a camera sensor (without any other lenses -neither camera lenses nor eyepiece lens). This projection ability is illustrated in this video at about the 3:00 minute mark: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-58N5I5oGLLE.html The basic optics of microscopy are explained in this video: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-uB48D5KueU8.html
