My astro CCD has a (slow) fan attached the peltier. The vibration isn't usually a big deal for two main reasons:
1) If your setup is sophisticated enough that fan vibration may cause an issue, you're likely already using a german-equatorial mount and some kind of guiding correction (secondary guide scope, or off-axis guider). These adjust the scope's positioning in real-time to keep on-target. So that removes any large-scale deviation that may be caused.
2a) Small-scale deviation is generally not a problem, since most setups are likely to be limited by the resolution of your entire optical train. For example, my 800mm newtonian combined with a CCD with 7.2mm pixels means I have a resolution of ~2.01 arc-seconds. Assuming perfect guiding, my scope can tolerate any vibration as long as my target stays within ~2 arc-seconds. *
2b) In reality, most locations are limited by seeing conditions (e.g. how turbulent the air is), which averages 1-3 arc-seconds in non-mountain regions. Also the calibration of your mount (periodic errors, guiding errors, etc) are almost certainly a greater concern than the vibration added from the peltier.
That's from an amateur's perspective. Obviously high-end setups will start to worry about things like the fan's vibration, but for someone with a backyard setup (doubly so for someone using a consumer DSLR instead of dedicated CCD), there are bigger causes of inaccuracy :)
* This is a bit of a simplification, since things get a bit more complicated due to FWHM, wavelength, etc.
Ugh, yeah, backlash on mine too :( I'm actually in the middle of rebuilding my mount to help with periodic errors and backlash. Replacing a bunch of bearings, re-greasing, replacing the direct gear train with a geared-belt system, etc.
Speaking of... I need to finish that up soon before winter season starts in earnest!
Most actual cameras dedicated for astrophotography (the stuff shown in the article is more like a frankenstein improv) have fans. Most of the large dobsonians have fans. Many high-end SCT telescopes (typically used for astrophotography) also have fans. Fans are good, fans are your friend. They fight all sorts of thermal issues.
They're typically fans with high quality bearings that also are spinning slowly. There's essentially zero vibrations coming out of that.
It's very hard to get decent results out of any optical stack, especially for photography, without having any sort of fans, heaters, coolers, and other air flow and temperature management devices in various places.
From one of the links elsewhere, they're claiming it doesn't: "[...] the relative speed of the cooling fan (which does not introduce vibrations) [...]".
Perhaps they use the fan to initially cool the sensor and then switch it off and let the Peltier cooling maintain the temperature or something?
I would be concerned about this as well. I've not done a lot of astrophotography, but when I have, I've had to make my framing/focusing adjustments, then wait anywhere from 10 to 60 seconds for the vibrations that motion introduced to fade away, before I used a wireless remote to trip the shutter. Obviously this is worst with a long lens[1], but I seem to remember it being a factor with any of the telephoto lenses I tried. This was using a Manfrotto tripod and head.
Seems like some sort of liquid cooling system where the radiator/fan assembly was not mechanically coupled to the camera body (except by flexible plastic tubing) would be a better approach.
[1] For example, I have an antique 400mm focal-length lens that really is about 400mm long. With it attached to the tripod near the middle, and the camera at one end, there is a lot of potential for bouncing around.
Part of the idea is that you will need significantly shorter exposures. Shorter than would be needed to introduce artifacts from vibration.
Such cameras (sold by Nikon [1]) are routinely used on high-end microscopes. They usually have a smaller resolution though - 1024x1024 is pretty common. There are a number of technologies used in scientific microscopy that work well for night-time photography, but most are just too expensive. Electron multiplying CCDs, chilled CMOS sensors, etc. They end up being one of the more expensive parts to a half-million dollar scope though.
In astrophotography, this is actually the opposite of what you want to do. Generally you add cooling so that you can let your sensor run for longer, so you can collect more photons without increasing the noise appreciably.
Image stacking can reduce noise afterwards, but there's no substitute for collecting more photons to increase the signal in an image... and the only way to do that is to try and clean up the noise floor (via cooling, better sensors, etc) :)
Peltier cooling or heating does require a fan.
The peltier cell only moves heat from on side to the other side. Then, you still have to remove the heat somehow (heat doesn't simply dissapear) that's why most peltier setups have fans.
The 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.
You've missed out the rotational modes, which matter hugely. A fraction of a degree on a long telephoto lens is a huge part of the frame. (If you're focusing at infinity the translational modes theoretically shouldn't matter at all)
Much 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.
Only 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.
