Are fan-cooled cameras, like Altair Hypercam 294C PRO Colour, nearly as good as peltier cooled cameras? Are they much better than DSLRs

[gerardsheldon]

I have a DSLR, 1000D canon, and want to upgrade my camera for deep space objects.  As always, there are lots of choices.  My options are:

1) get a better DSLR with lower dark noise

2) get a fan-cooled carmera like the 9294C Altair Hypercam

3) get a peltier cooled camera like the ASI533 peliter cooled camera 

I live in a quite a light polluted area, though occasionally I will go to dark locations.

My questions are: 

a) can one get a DSLR with low dark noise that can perform similarly to a peltier cooled camera?

b) Is it a false economy to go for a fan-cooled camera instead of a peltier cooled one?  (I can't find any information about the temperature drop from a fan-cooled camera). 

 

 

[vlaiv]

This is actually not an easy question to answer as there are a lot of things in play.

Best option (but not always) is Peltier cooled dedicated camera with set point temperature.

Being at low temperature is not that beneficial in some cases (in some it is) - but being at set point temperature is very important. It allows you to properly calibrate your data.

I'm going to list pros and cons of dedicated non cooled / air fan cooled vs DSLR

Neither is capable of achieving set point temperature (not even air fan cooled as it depends on ambient air) which means that neither is capable of proper calibration.

DSLR pros:

- very large sensor for the money (often APS-C). This is important bit as it can mean significant increase in SNR if used properly

- has internal dark calibration (most modern DSLRs do). This is both pro and a con - depending on how you look at it. Pro is that you can get good dark calibration if sensor has uniform dark current noise (no amp glow) - and in most cases this is true. Con is that it is not proper calibration and that it makes subs noisier than they need to be (using just few pixel values for dark current reduction as opposed to stack of dark subs).

DSLR cons:

- Not as easy to work with as dedicated astronomy camera attached to laptop (this is subjective)

- Has very restrictive IR/UV cut filter installed and if you want good sensitivity across all visible range - you need to remove / replace that filter (not easy or cheap operation)

- Can't achieve higher FPS or be used for planetary imaging

Dedicated astro camera without TEC (air cooled or regular) Pros:

- Full spectrum sensitivity

- Fast readout

- Usually higher QE than DSLR

Cons:

- Very complicated dark calibration that depends on algorithms and is not 100% correct ( again - no proper calibration)

- Expensive - small area sensors available in price range of DSLR

Bottom line - I'm not sure which one I would choose - and even maybe am leaning towards DSLR. You really need to crunch the numbers to see which one is better.

Both have awkward dark calibration (DSLR is actually easier in this regard). Probably only issue with DSLR that is really important is that nasty UV/IR cut filter that needs replacing / modding.

Lower QE is offset by the size of sensor.

Place larger sensor to the larger telescope (to get the same FOV) and match resolution - you have faster system with DSLR as aperture is larger and collects more light. That offset lower QE.

[rnobleeddy]

One thing to add to @vlaiv's list is that the astro cameras almost always double up as a guide camera and can also be used for planetary, lunar or solar photography. So for example, I used to use a DSLR for nebula and galaxies, with a ZWO camera for guiding, and then it could also be used for lucky imaging.

 

My personal view of a fan cooled astro camera is that it can only be a good thing to have a cooler chip - but I wouldn't pay much for fan cooling over the cost of one with no cooling.

[ollypenrice]

Peltier cooled camera every time for me. CCD cameras on the used market are becoming bargains and they still take great photos.

Olly

[DaveS]

Yes, peltier cooled every time. If you buy a camera that's only fan cooled you'll soon be thinking "what if...", and "If only..."

[gorann]

Mesages on this thred are getting shorter and shorter for a good reason: Peltier every time! I do not understand why Altair keeps on trying to sell their fan cameras. If you just have a fan you cannot hold a stable temperature and get appropriate calibration frames like darks, so essentially you cannot calibrate the subs.

[Bibabutzemann]

depens on your budget and your scope.

For example:

If you have a scope that can correct full frame size sensor and a budget of 800 Dollar, i would buy a used EOS 6D over a cooled ASI 533.

I agree with the others, i would always save money for a peltier cooled, before buying a fan cooled. 

 

 

[tomato]

Might be ok on top of a mountain, but down in the lowlands with plenty of ambient temperature variation, Peltier cooler every time. You can retro fit the coolers for a modest cost, but it will void your warranty and they won’t perform as well as a factory installed item.

With the latest CMOS cameras, keeping the sensor temperature stable is more important than sub zero cooling, but you need a cooler to achieve that.

[Alien 13]

I would chose a DSLR over a fan cooled camera for the reasons listed below.

Self contained, no need for a heavy power supply or a laptop.

Bigger sensor.

The argument over QE is less of an issue, my now old camera has a QE of 54 which is in the same ballpark as a lot of dedicated CMOS devices.

Perfectly matched to camera lenses regarding inbuilt filters.

Inbuilt focusing aids.

Alan

 

[alacant]

12 hours ago, gerardsheldon said:

get a better DSLR

Hi

The 1000d is over 20 years old. You'll see a big difference between it and a modern eos.

Have a look at/borrow a 600d, 700d 4000d... They and a few others all share the excellent 18mp sensor and can be had for a tenth of the price of a cooled model with the same sized sensor. They're also rugged and built to last.

Just our €0,02 but HTH.

 

 

 

[Stefek]

Well , every task requires appropriate tools . I tried all 3 types. Have Altair fan cooled 178c, using it for planetary . Of course, fan can't cool it below ambient , but keeps the temperature at ambient or around.  It does not add anything much to the image quality so I removed it. 

Was also using Nikon, after a while usb connector became a bit loose, had to add additional 9V power supply (DC/DC converter) , clip in filters are more expensive... removing IR filter expensive again cost something,...

At the end, got myself proper cooled astro camera .... so again the tool for the task. 

 

 

[gerardsheldon]

Thanks,  that is really clear.  Don't bother with fan cooled.   If I can afford it, go for a decent peltier cooled camera.  Otherwise go for a modern DSLR.  There is a good company in the UK that modifies canons to allow Hydrogen alpha. (cheap astrophotography). 

Edited April 16, 2022 by gerardsheldon

[DaveS]

13 hours ago, Stefek said:

Well , every task requires appropriate tools . I tried all 3 types. Have Altair fan cooled 178c, using it for planetary . Of course, fan can't cool it below ambient , but keeps the temperature at ambient or around.  It does not add anything much to the image quality so I removed it. 

Was also using Nikon, after a while usb connector became a bit loose, had to add additional 9V power supply (DC/DC converter) , clip in filters are more expensive... removing IR filter expensive again cost something,...

At the end, got myself proper cooled astro camera .... so again the tool for the task. 

 

 

"The right tool for the job" sums it up perfectly. Yes you can bodge out images with a modded DSLR or even a fan cooled camera, but it's a bit like asking Grinling Gibbons to carve an alter screen using a sharpened screwdriver  (I know they didn't have screwdrivers in the 17th century) instead of a finely honed chisel.

[Quatermass]

Interesting thread, I have just purchased the Altair Astro Hypercam 294c fan cooled camera because it was 600.00 and at my budget. This is to move up from using a Canon 450d and many years of using a DSLR. Having been already baffled by the many new things to puzzle over, gain, offset, binning etc I just went out a few nights ago to try it out. I have to say I was blown away by the difference this camera produced even though I have not fully got to grips with it I could see that this was a real game changer from using the DSLR.

For example just using only 10 of the fit files it produced on the subject of the Orion Nebula and stacking them in deep sky stacker with no calibration frames at all I was able to get this image. Yes I know its colours are not quite right but I am colour blind and this was a very quick process in PS. But having used a dslr for a long time this was amazing the noise level was virtually gone compared to my Canon 450d and not having to keep changing battery's was great and also focusing was so much easier to do.

This image was not even trying compared to what I normally do and with the addition of  a Ha filter the potential for much better imaging is now a reality.  Ok so its not the more expensive cooled version but that does not really matter to me as my set up is permanent and I can do my darks the same night. So I have to say I absolutely love this camera and very glad I have made the jump from my beloved Canon 450d.

[City9Town0]

Just SCNR'd your image.

[ollypenrice]

On 15/04/2022 at 22:41, alacant said:

Hi

The 1000d is over 20 years old. You'll see a big difference between it and a modern eos.

Have a look at/borrow a 600d, 700d 4000d... They and a few others all share the excellent 18mp sensor and can be had for a tenth of the price of a cooled model with the same sized sensor. They're also rugged and built to last.

Just our €0,02 but HTH.

 

 

 

It's 14 years old but you're still right, progress has been enormous.

Olly

[michael.h.f.wilkinson]

I have imaged with DSLRs, non-cooled (essentially planetary) CMOS cameras, and Peltier-cooled CMOS cameras. My first foray with a DSLR was with a modded EOS 450D, which worked, but the later 550D completely blew it out of the water

I then started using my non-cooled ASI183MC with the Meade Schmidt-Newton, with quite pleasing results:

Getting darks for every single temperature you are working on was a bit of a pain, however.  I then migrated to Peltier-cooled cameras, which make life so much easier in grabbing a dark library once for you favoruite set-point cooling. 

 

Having said that, I still use the DSLR for wider-field imaging

[Dark Raven]

You can also Peltier cool DSLR/M with Tilta’s Canon EOS R5, R6 cooling fan. 

 

 

And you can Peltier cool uncooled planetary AP cameras with Black Shark Magnetic Cooler

 

Neither will be as good as a dedicated cooled AP camera but it may help if you are already invested in DSLR/M or planetary cameras.

I tested the second option, and you can hardly beat the price.

[Stu Wilson]

Hey i know its not the sales page but i still got a QHY8L up for grabs for sensible price. IM me

 

Stu