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Cooled Nikon D5500a Chills the Sensor for Clearer Star Photos
- DigitalJack 10y agoThat's really interesting. Better watch out for condensation on the electronics.
- blincoln 10y agoThe actual product page that foenix linked to (http://www.primalucelab.com/astronomy/d5500a-cooled-camera.html http://www.primalucelab.com/astronomy/d5500a-cooled-camera.h...) mentions that there is an anti-dew system for at least some of the internal bits.
- foenix 10y agoDirect link to the product page which has the same images and description and isn't blog spam: http://www.primalucelab.com/astronomy/d5500a-cooled-camera.html http://www.primalucelab.com/astronomy/d5500a-cooled-camera.h...
- jplahn 10y agoMeta question: what do you consider spammy about this blog post? It seems like a perfectly fine, digestible narrative of the product without requiring the reader to sift through a product page. On a more related note, I find it interesting that the product page says there's a 4 year warranty on the camera body. I didn't see anything about the warranty on the mod itself.
- andrewguenther 10y agoI agree, the blog post is a much better quality post. Also, I would imagine a direct link to a product page would turn a lot of people off.
- foenix 10y agoOh, looks like the OP link was updated since I posted that. The original link was to Gizmodo: https://gizmodo.com/this-upgraded-nikon-chills-the-sensor-for-clearer-shots-1787743794 https://gizmodo.com/this-upgraded-nikon-chills-the-sensor-fo... I should have linked to the original Petapixel post on the bottom of that Gizmodo page. My bad.
- jychang 10y agoPetapixel is half blogspam anyways, a tiny step up from Gizmodo. It was actually banned from r/photography for spam reasons.
- gohrt 10y agoAdmins/Mods, can we ban titles that use clickbaity "This"?
- matt_wulfeck 10y agoThere's simply no way that the fans don't cause considerable vibration artifacts for such long exposures. Am I missing something?
- maxerickson 10y agoThe focus is infinity, so as long as the camera is rigidly mounted the vibration that makes it past whatever damping they have won't wobble the field of view a lot. For $1000+ I imagine the fans actually don't have much impact.
- StavrosK 10y agoWhy does the focus matter to vibrations? Things vibrate wherever you're focused.
- jacquesm 10y agoIt all depends on the axis of the vibration. Front to back won't matter much, side to side will matter as soon as it is > .5 CCD elements.
- anotheryou 10y agoMuch more sensitive, the motion will be amplified by the zoom factor. It also introduces (minor) blur as soon as the image shifts further than the gap between the sensor pixels.
- CamperBob2 10y agoSounds like an accelerometer might give you the information needed to deconvolve that effect. Has anyone looked into that?
- anotheryou 10y agoOnly if you have a time resolution higher the shaking. How do active image stabilizers work? Edit: yes, that's how active systems work: gyro stuff and counteracting by moving the lens or the sensor¹. For astronomy rather a lens, because the sensor would have to move too far for the big shifts the tele causes². ¹ http://photo.stackexchange.com/questions/804/how-does-image-stabilization-vibration-reduction-work http://photo.stackexchange.com/questions/804/how-does-image-... ² https://photographylife.com/lens-stabilization-vs-in-camera-stabilization https://photographylife.com/lens-stabilization-vs-in-camera-...
- andy_ppp 10y agoWould combining Peltier coolers with CMOS/CCDs on high ISO photos work? How much of the noise at higher ISO is heat, little I'm guessing?
- abakker 10y agoYou'll notice on this page - http://www.primalucelab.com/astronomy/d5500a-cooled-camera.html http://www.primalucelab.com/astronomy/d5500a-cooled-camera.h... - that the before/after photo is taken at ISO 6400.I consider that to be reasonably high ISO. But yes, at some point, heat is not the primary issue anymore.
- Sanddancer 10y agoQuite a bit, actually. It's why high end telescope CCDs do similar things. A high ISO means you're ramping up the gain, so the bits of random noise get amplified too. Cooling it means you're getting rid of one of the more significant sources.
- wlievens 10y agoOn a CMOS higher ISO is just increased analog amplification. If your pixel is measuring thermal noise the. You will amplify that too I guess.
- mutagen 10y agoI recently ran across this homemade camera mod [1] to reduce astrophotography noise. There's some brief notes on creating it somewhere in the creator's (James Tobin) profile [2] but G+ isn't the happiest place to search. Edit: Found one of them [3] [1] https://get.google.com/u/0/albumarchive/110103212360961433158/album/AF1QipNHCy7jXdvjcNpJonAk2aRuyBxEEiIOq329Mloq https://get.google.com/u/0/albumarchive/11010321236096143315... [2]https://plus.google.com/110103212360961433158 https://plus.google.com/110103212360961433158 [3]https://plus.google.com/110103212360961433158/posts/58k5AgTxwku https://plus.google.com/110103212360961433158/posts/58k5AgTx...
- dom0 10y ago> “It’s the first ever cooled Nikon camera ever for astrophotography,” * first ever commercial The technique isn't at all new, even in DSLR space.
- anon1253 10y agoNot quite sure why this hits the front page. Most serious astrophotographers have been using similar setups for a while now, or ideally peltier cooled CCDs (like Starlite Express, Atik or QHY cameras). More recently cooled CMOS sensors (like the ZWO1600MM-Cool) have also gained popularity. It's a bit of niche market, but for long exposure photography having a cooled sensor greatly reduces thermal noise. And since the signal is very faint you often do a lot of "histogram stretching", bringing out the signal, but also the noise. In addition to having a low noise camera you also often do things like bias, dark and flat callibration, reducing impurities further. Dark subtraction is often known as "long exposure noise reduction" in consumer cameras, but astrophotographes like to do it manually. There are a lot of details to consider when doing astrophotography, but I'm always happy I can set my CMOS or CCD (own both the QHY10-OSC and ZWO1600MM-Cool) to a deltaT of -40ºC.
- mustpax 10y agoThe reason that this is on the front page is because not everyone is a serious astrophotographer. If you find yourself asking "I already know about this, why is this on the front page?" Take a moment, you've just answered your own question.
- deleted 10y ago[deleted]
- Florin_Andrei 10y agoThe article is mildly interesting, but this is not state of the art by any means. It's a little bit like an article saying "computer engineers use special software that could take human readable source code and convert it into executable binaries for faster execution". A layperson would have their minds blown, but it's a super-yawner for those in the industry.
- tgb 10y agoPlease post a better article: I'll upvote it!
- peignoir 10y agoUsed to do that with an ST6 back in the 90s :)
- Hasz 10y agoThey're essentially using Peltier elements to cool the elements electronically. They're also using two elements stacked in series for a lower total temp. Thank god the CCD is small -- a Peltier unit, as a heat pump, is pretty inefficient, topping out a ~15%, at a low t delta. When you stack two on top of each other, the efficiency is now 2.25%, and this only gets worse as the delta increases or more units are added.
- Retr0spectrum 10y agoThe CCD also doesn't generate that much heat, so the peltier cells don't need to do that much work.
- Apreche 10y agoIs this more effective than dark frame subtraction?
- raverbashing 10y agoNo because dark frame removes the systemic differences between sensors, not noise
- raverbashing 10y agoIf you can't tell the difference between the chilled and regular frame I have to suggest taking the dust out of your monitor, as in certain conditions the difference might not be visible (I just did that)
- GregBuchholz 10y agoAnyone using liquid nitrogen to cool their CCDs on a hobby / amateur level?
- anon1253 10y agoNot that I know of. CCDs don't generate a lot of heat, so the cooling only has to be relative to ambient, which peltier can do fine. I'd worry more about things like thermal shock when pouring liquid nitrogen over a CCD than the gains in Signal-to-Noise ratio. Although, there are scientific instruments that get cooled way further into super conducting state.
- aortega 10y agoCCDs generate lots of heat. Maybe you are thinking about CMOS sensors, much more efficient, but even cmos sensors overheat in many cameras.
- tomkinstinch 10y agoHobby use would be a pain: LN2 could be used, but it boils off so a dewar would need to be constantly refilled. For sensor applications where cold matters but a Peltier TEC is insufficient, a Stirling/Joule-Thomson/turbo-Brayton/Gifford–McMahon cryocooler can be used to remove heat, but they're expensive (this is how the Hubble Space Telescope does sensor cooling). They often have high-pressure LN2, neon, or helium as the working fluid, with a cold head attached to the sensor and a remote compressor. Cryocoolers are also used to chill superconducting RF filters (of the sort that may be used in cell phone towers). They're also used to cool MWIR sensors, and thus are often ITAR-controlled. Sometimes higher-temp cryocoolers pop up on eBay...
- CamperBob2 10y agoSometimes higher-temp cryocoolers pop up on eBay... One of Ben Krasnow's videos comes to mind: https://www.youtube.com/watch?v=7PWESWqhD8s https://www.youtube.com/watch?v=7PWESWqhD8s
- camtarn 10y ago
- Keyframe 10y agoSensor cooling can lead to moisture appearing in the camera, so the D5500a Cooled uses a special anti-dewing system that uses targeted heat to avoid dew drops appearing. I'd like to hear more about this.
- ucaetano 10y agoYour refrigerator probably has the same technology.
- polyfractal 10y agoThese are often called "dew heaters", and are really quite simple. It's usually nichrome wire (e.g. what you see in a toaster), or sometimes a bunch of resistors. The tiny amount of heat generated by these straps are enough to raise the optical port a degree or two above the dew point. My QHY8 (a dedicated astro CCD) for example has a poor/old design, where the CCD compartment is not air-tight. This allows humid air to get inside, which can then fog up the optical glass due to the peltier cooling the sensor down. The fix is a small ring that screws into the port, and raises the temperature just enough to combat dew. You could also wrap a dew heater strap around the part of the optical train at that point for a similar effect. Dew (and frost) are the astrophotographer's great, persistent enemy and not just on the CCD. You'll also have dew problems on the telescope itself. For example, my newtonian sometimes has dew problems on the secondary mirror, occasionally on the main mirror, and always on my guide scope. Most people just create some DIY dew heater straps with nichrome wire... it's super simple and effective.
- Keyframe 10y agoInteresting. So it's a heating element (wire) which serves as a controlled heater to keep the close environment above dew point. If it's controlled, that is. Maybe it works as a dumb heater also? OTOH, I've never considered somewhat more performant (not to say extreme) cooling of CMOS in order to eliminate noise. I'm surrounded by CMOS and CCDs every day, in film cameras and telecines (both array and linear chips). I knew, and saw, that temperature can influence noise, but apart from staying within 'normal' operating range, I never considered it would eliminate more noise if significantly cooled down. Probably because I knew noise was inherent to the way those things work and not much could be done to eliminate it altogether. Interesting. I'll try to experiment with a bit more extreme cooling on my equipment to see what yield would come out of it. I'm not that concerned about dew, because equipment is in controlled environment (dry and +-2C deg. stable environment), but nice to know.
- wyager 10y agoGiven the fact that (correct me if I'm wrong) camera sensors use the same sensor elements for red, green, and blue, but with a different filter in front, it seems strange to me that blue and green are almost eliminated by the cooling but red remains to a large degree. I would expect this distribution if the camera used different photodiode types sensitive to their respective color range.
- planteen 10y agoWhat makes you say that blue and green are eliminated? The stars are still white. The California nebula itself is mostly red. https://en.wikipedia.org/wiki/California_Nebula https://en.wikipedia.org/wiki/California_Nebula
- wyager 10y agoI mean in the noise image.
- aortega 10y agoMost CMOS sensors are much more sensitive in the red/infrared spectrum, that's why all cameras have a IR cut-out filter. This filter is removed in astrophotography cameras (you want all the light you can get) giving aprox. 50% more light gathering, but mostly in red/IR colors.
- wyager 10y agoThat doesn't explain why the noise image is red, given that the noise excitations are endogenous and don't go through the filter, does it? Unless that noise isn't noise at all but IR from the room.
- deleted 10y ago[deleted]
- thebakeshow 10y agoQuestion to those astrophotographers out there. I notice the cooler has a fan on it, is the fan vibration damped somehow? I shoot a lot of long distance photos (300mm F/2.8 and 600mm F/4 are my main lenses). Any vibration is greatly amplified when I shoot, and this is a much longer range than that.
- cperciva 10y agoI notice the cooler has a fan on it, is the fan vibration damped somehow? I'd assume that the fan is simply turned off for the duration of a photo (plus the time it takes for vibrations to decay). The sensor won't heat up instantaneously.
- aortega 10y agoGood question. I have a peltier cooled ccd (atik 460) and the fan stays on during the entire exposure, but it doesn't affect the final picture at all, touching the camera I can't feel any vibration, but can hear the fan. Quality is much better than in my fanless Canon 400D.
- madaxe_again 10y agoMost Pelletier chilled assemblies use magnetic bearings for fans, so very low shake. I use an Orion star shoot G3 (can't really recommend it), but vibration from quarrying 20 miles away is more of a problem than the fan. Oh, and that's on 2032mm f/10.
- fest 10y agoThere is a saying in electronics engineering world: "Every sensor is also a temperature sensor." What this means is: almost every electronic sensor is affected by it's temperature- from expensive image sensors to cheap MEMS accelerometers and gyroscopes. That is why many of digital sensors also report their temperature, although that is not their primary purpose- so that current temperature effects on the measured result can be calibrated out either in sensor's logic, or by host software.
- gnipgnip 10y agoErm, you can't calibrate out Boltzmann noise.
- planteen 10y agoI think OP meant calibrating out noise that leads to a bias (non-zero mean) that changes with temperature. Such things are common in many sensors.
- cperciva 10y agoYou can calibrate out the mean "light level" resulting from Boltzmann noise. You can't calibrate out the variance, but eliminating the mean noise is better than nothing.
- robzyb 10y ago> There is a saying in electronics engineering world: "Every sensor is also a temperature sensor." I've never heard that before, but its awesome. Though, it could probably be generalised to "every component is also a temperature sensor."
- abetusk 10y agoI was experimenting with visual calibration of my desktop CNC by hooking up one of those cheap USB 1000x cameras. I had done some back of the envelope calculations to figure out that it was about 5 pixels per thousandth of an inch. After a few hours of getting weird inconsistent results, I finally figured out to my shock and horror that the image was drifting and warping by upwards of 20 pixels after the camera had been one for a while (I think it was 640x480 resolution). My friend and I thought this was due to the CCD heating up and warping. It looks like they're using the cooling for noise suppression but I bet the CCD also has the same effect I noticed of 'pixel drift/warp'.
- maxxxxx 10y agoI wonder why they didn't pick a full frame camera like the D750. This would make more sense to me.
- amdavidson 10y agoAPS-C sensor cameras get you an effective 1.5x multiplier on your focal length, handy for astrophotography. You could always crop down a full frame photo to get the same effect, but then you're just wasting pixels.
- deleted 10y ago[deleted]
- toomanybeersies 10y agoI'm amazed at the difference only 20 C makes. Does this mean I'd get much better photos in winter than summer?
- raihansaputra 10y agoit's not that much of a difference if you're shooting less than 15seconds exposure.
- anovikov 10y agoNo way this will beat a dedicated astronomy CCD camera. And price point is already not so attractive, ST-8300C costs $1995 and while has 30% less sensor area, is light years away in thermal current at given temperature, and quantum efficiency. For me, if a wanted a color camera (bad idea most of the time), picking between ST-8300C and this would be a no brainer in favor of ST-8300C.