Which ZWO Astro camera?

[CraigD1986]

Hi all.

I’m still very new to astrophotography but am looking to upgrade to a ZWO camera to use with my Sigma 150-600mm camera lens via the ZWO Canon EF mount adapter (Currently using a Canon 5D Mk IV). My thoughts are that a cooled camera will enable me to take better calibration frames and to also create darks the next day rather that eating into imaging time.

I don’t think I want to spend much more that £1000 so budget dictates it should be one of these:

https://www.firstlightoptics.com/zwo-cameras/zwo-asi-533mc-pro-usb-30-cooled-colour-camera.html

https://www.firstlightoptics.com/zwo-cameras/zwo-asi-294mc-pro-usb-30-cooled-colour-camera.html

I’m struggling to understand the differences between the two, aside from the sponsor size. Is anyone able to advise? Both get brilliant reviews.

[Adam J]

24 minutes ago, CraigD1986 said:

Hi all.

I’m still very new to astrophotography but am looking to upgrade to a ZWO camera to use with my Sigma 150-600mm camera lens via the ZWO Canon EF mount adapter (Currently using a Canon 5D Mk IV). My thoughts are that a cooled camera will enable me to take better calibration frames and to also create darks the next day rather that eating into imaging time.

I don’t think I want to spend much more that £1000 so budget dictates it should be one of these:

https://www.firstlightoptics.com/zwo-cameras/zwo-asi-533mc-pro-usb-30-cooled-colour-camera.html

https://www.firstlightoptics.com/zwo-cameras/zwo-asi-294mc-pro-usb-30-cooled-colour-camera.html

I’m struggling to understand the differences between the two, aside from the sponsor size. Is anyone able to advise? Both get brilliant reviews.

ASI533mc as it has no calibration issues with duel narrow band filters.

Adam

[bottletopburly]

I have the zwo533mc and it’s a game changer 👍

[AstroNebulee]

This may be of help to you. 

I went with the 294mc pro just for the bigger sensor size. The amp glow on the 294mc pro can be calibrated out. 

Edited January 8, 2022 by AstroNebulee

[Pitch Black Skies]

Apart from the sensor size and shape. I think the next main difference is that the 533 has zero amp glow, although that could be easily calibrated out with darks on the 294.

Here is an example of 2 hours work from my 533. I didn't use any darks, flats, dark flats etc.

I think you will be pleased with either camera. It's personal preference really.

Best of luck.

[Budgie1]

15 hours ago, CraigD1986 said:

Hi all.

I’m still very new to astrophotography but am looking to upgrade to a ZWO camera to use with my Sigma 150-600mm camera lens via the ZWO Canon EF mount adapter (Currently using a Canon 5D Mk IV). My thoughts are that a cooled camera will enable me to take better calibration frames and to also create darks the next day rather that eating into imaging time.

I've got better news for you; you can create a Darks Library when it's cloudy and just re-use the Darks, no need to create a new set after each session.   You can do this as long as you use the same temperature, gain & offset settings and create a set of Darks for all the exposure settings you're likely to use. 

I went for the ASI294MC Pro because I prefer the sensor shape to the square one on ASI533. It gives me better framing options and, as has been mentioned above, the amp glow on the sensor is calibrated out with Darks. I did notice with mine that using Bias frames caused a residual of the amp glow to remain on the image, so I only use Darks, Flats & Dark-Flats.  

[PeterCPC]

I just imaged IC405 (see other thread) with my 533 set at -10C and I did not use any callibration frames in the processing.

[Pitch Black Skies]

11 minutes ago, PeterCPC said:

I just imaged IC405 (see other thread) with my 533 set at -10C and I did not use any callibration frames in the processing.

What thread are you referring to? I'd like to have a look.

[PeterCPC]

 

[The Lazy Astronomer]

To be honest, it's six of one and half a dozen of the other. Both cameras would give you great results. The 294 will require a little bit more attention with calibration, but it's no more difficult than making sure you have good matched darks for your lights.

Basically, do you want a square sensor or a rectangular one - that's about the only real difference. 

[CraigD1986]

Thanks everyone for the replies. It sounds like I can’t go too far wrong with either.

 

@Adam J That’s interesting about the filters. I’ve never used filters but would like to try in future so I’ll look into this. 

@Pitch Black Skies That’s absolutely stunning and amazing to say there are no calibration files used.

@Budgie1 Yeah, calibration file libraries are a big reason for me wanting to upgrade. I read somewhere that you can do the same with Flat or Bias (Can’t remember which one).

 

I was initially leaning away from the 533 due to the square sensor (although I have no particular reason for this) but I’m leaning toward it a bit now as I feel it might give me more flexibility time wise with not relying so heavily on calibration frames.

Both cameras so seem to have pretty low resolution (9MP and 12MP) compared to my 5D Mk IV at 30MP. Should this concern me?

Also, there is a slight difference in pixel size between the 533 and 294. What are the implications on this?

 

Should I also consider the ASI183MC Pro?

https://www.firstlightoptics.com/zwo-cameras/zwo-asi-183mc-pro-usb-3-cooled-colour-camera.html

[Adam J]

3 minutes ago, CraigD1986 said:

Thanks everyone for the replies. It sounds like I can’t go too far wrong with either.

 

@Adam J That’s interesting about the filters. I’ve never used filters but would like to try in future so I’ll look into this. 

@Pitch Black Skies That’s absolutely stunning and amazing to say there are no calibration files used.

@Budgie1 Yeah, calibration file libraries are a big reason for me wanting to upgrade. I read somewhere that you can do the same with Flat or Bias (Can’t remember which one).

 

I was initially leaning away from the 533 due to the square sensor (although I have no particular reason for this) but I’m leaning toward it a bit now as I feel it might give me more flexibility time wise with not relying so heavily on calibration frames.

Both cameras so seem to have pretty low resolution (9MP and 12MP) compared to my 5D Mk IV at 30MP. Should this concern me?

Also, there is a slight difference in pixel size between the 533 and 294. What are the implications on this?

 

Should I also consider the ASI183MC Pro?

https://www.firstlightoptics.com/zwo-cameras/zwo-asi-183mc-pro-usb-3-cooled-colour-camera.html

In theory the larger pixels will deliver a slightly better signal to noise ratio. I dont recommend the ASI183mc pro in anything except very fast optical systems as I'm most cases your conditions and scope are unlikely to realise the resolution provided by those small pixels. 

[jacko61]

28 minutes ago, CraigD1986 said:

 

@Budgie1 Yeah, calibration file libraries are a big reason for me wanting to upgrade. I read somewhere that you can do the same with Flat or Bias (Can’t remember which one).

 

I was initially leaning away from the 533 due to the square sensor (although I have no particular reason for this) but I’m leaning toward it a bit now as I feel it might give me more flexibility time wise with not relying so heavily on calibration frames.

 

You have to do your flats at the same time as your light frames unless you leave your scope set up with the camera till the next day. Flats are a record of any dust particles or vignetting etc AT THE TIME THE IMAGE WAS TAKEN.  Obviously if you move your camera or adjust focus, the dust bunnies will move and the flats will be useless (the calibration processing subtracts the dust bunnies from your image).

I don't bother with Bias frames. I read somewhere that they're not needed (or even advisable) for modern CMOS astro cameras.

I bought the ASI533 and can recommend it for ease of use. I quite like the Square format but if I need a rectangular image it's simple enough to crop the image. Here's the most recent image I took. 90 minutes of lights, 15 flats that took less than 2 minutes to record at the end of the session plus darks I used from the library I built up a month or two ago (cooled cameras are brilliant!)

Graeme  

 

Edited January 9, 2022 by jacko61

[vlaiv]

30 minutes ago, Adam J said:

In theory the larger pixels will deliver a slightly better signal to noise ratio. I dont recommend the ASI183mc pro in anything except very fast optical systems as I'm most cases your conditions and scope are unlikely to realise the resolution provided by those small pixels. 

Or perhaps binning?

 

[Pitch Black Skies]

6 hours ago, CraigD1986 said:

Both cameras so seem to have pretty low resolution (9MP and 12MP) compared to my 5D Mk IV at 30MP. Should this concern me?

I think it will only be a concern if you want very large prints of your images.

As you probably already know the general recommendation for printing is 300ppi (pixels per inch). I can print 12"×12" which is about 250ppi and the image still looks quite resolved up close.

 

It might be worth sending FLO a quick email asking them which one they would recommend. There are very helpful.

Edited January 9, 2022 by Pitch Black Skies

[Adam J]

2 hours ago, vlaiv said:

Or perhaps binning?

 

Would kinda turn it into a much smaller 294 with higher read noise though for 80% of the price?

Adam

Edited January 9, 2022 by Adam J

[vlaiv]

18 minutes ago, Adam J said:

Would kinda turn it into a much smaller 294 with higher read noise though for 80% of the price?

Adam

I'm all for 294 - from performance / price standpoint - it's probably one of the best (together with 2400pro - $4 per mm2).

[Adam J]

15 hours ago, vlaiv said:

I'm all for 294 - from performance / price standpoint - it's probably one of the best (together with 2400pro - $4 per mm2).

Its a good camera, but i think if your target will fit onto a 533 then its a better camera. I think that the 2400pro is a great camera if you can afford one. 

 

Adam 

[drjolo]

You may also consider FOV for your imaging targets. 533 is significantly smaller chip, it has 128mm2, while 294 has 248mm2. It may look like a few mm larger in the specs, but that is actually two times larger imaging area. 

[CraigD1986]

Thanks everyone for the responses. It sounds like I'll be happy with either camera but I think I like the sound of the 533 so am going to look into getting one of these I think.

[900SL]

I'm looking at the same decision. Think I'll go with the 533. The square sensor means that FOV will be narrower on my GT71, compared to my APS-C, so framing is good on the usual suspects. The pixel scale is a good match, and the edge field flatness and abberation should be reduced compared to a rectangular sensor.

Plus no amp glow.

I assume you can shoot 2*1 and 2*2 panoramas for high resolution wide field fairly easily with a square sensor camera? 

[Richard_]

On 15/01/2022 at 08:20, 900SL said:

I'm looking at the same decision. Think I'll go with the 533. The square sensor means that FOV will be narrower on my GT71, compared to my APS-C, so framing is good on the usual suspects. The pixel scale is a good match, and the edge field flatness and abberation should be reduced compared to a rectangular sensor.

Plus no amp glow.

I assume you can shoot 2*1 and 2*2 panoramas for high resolution wide field fairly easily with a square sensor camera? 

Correct, you can shoot mosaics to widen the field of view with this smaller sensor.

I wanted to shoot the Veil nebula using my Redcat51 and ASI533 but I can only just fit it into my field of view. By the time you consider dithering and edge artifacts to crop, I'd lose some signal. So mosaic is the way! 

I planned my mosaic using the tool on telescopius.com which is really nice to use. It's critical that your rotation in the website and your telescope are very close because if you plan to shoot "four squares" (ie sides touching) but your rotation is out by 45°, you end up shooting "four diamonds" (ie corners touching) which would cause a lot of gaps between panels and would ruin your mosaic. After I planned the mosaic I just needed to copy and paste the RA and DEC coordinates as CSV into my ASI Air Pro in the Plan mode, it was very straight forward to do! Remember to take some test shots of each panel to verify you have orientation correct then off you go. 

I shot the below 2x2 mosaic with a higher overlap between panels than was necessary (~50%) as I didn't want any gaps in my panels on my first attempt! I spent some time ensuring that I had my rotation spot on which resulted in very little regions which did not overlap during registration, so I was really happy with it. Processing was interesting and I found that you do need to have a good amount of signal to get a good blend between panels (I think the below was 1.5hrs of l-extreme data per panel). Image dimension is 3,950 x 3,950 pixels, so about 30% wider and taller than native size. 

I've recently shot IC 443 Jellyfish nebula with about 25% Overlap using my 120mm refractor and the ASI533. I've yet to perform the mosaic merge, so it'll be interesting to see how it turns out! 

Edited January 17, 2022 by Richard_
Corrected typo

[900SL]

15 minutes ago, Richard_ said:

Correct, you can shoot mosaics to widen the field of view with this smaller sensor.

I wanted to shoot the Veil nebula using my Redcat51 and ASI533 but I can only just fit it into my field of view. By the time you consider dithering and edge artifacts to crop, I'd lose some signal. So mosaic is the way! 

I planned my mosaic using the tool on telescopius.com which is really nice to use. It's critical that your rotation in the website and your telescope are very close because if you plan to shoot "four squares" (ie sides touching) but your rotation is out by 45°, you end up shooting "four diamonds" (ie corners touching) which would cause a lot of gaps between panels and would ruin your mosaic. After I planned the mosaic I just needed to copy and paste the RA and DEC coordinates as CSV into my ASI Air Pro in the Plan mode, it was very straight forward to do! Remember to take some test shots of each panel to verify you have orientation correct then off you go. 

I shot the below 2x2 mosaic with a higher overlap between panels than was necessary (~50%) as I didn't want any gaps in my panels on my first attempt! I spent some time ensuring that I had my rotation spot on which resulted in very little regions which did not overlap during registration, so I was really happy with it. Processing was interesting and I found that you do need to have a good amount of signal to get a good blend between panels (I think the below was 1.5hrs of l-extreme data per panel). Image dimension is 3,950 x 3,950 pixels, so about 30% wider and taller than native size. 

I've recently shot IC 443 Jellyfish nebula with about 25% Overlap using my 120mm refractor and the ASI533. I've yet to perform the mosaic merge, so it'll be interesting to see how it turns out! 

Many thanks Rich, nice example and guidance.