ZWO 294MC or 533MC or an onother

[gonzostar]

Hi 

I'm currently using a ZWO385MC camera with a 102mm ES APO triplet. This is great for planetary of Lunar images and brighter DSO's.

However I would like to have a camera with a wider FOV, Was looking at the above camera's and FLO's on line tools for suitability, Which looked ok in the most at worst slight oversampling. 

I was wanting to know what your experiences with either the 294 or 533, please

 

Thankyou 

Dean

[Adam J]

You don't specify Mono or OSC, Also what is your actual budget?

[gonzostar]

Sorry, OSC upto £850max

[orly_andico]

For similar money, I'd go for the 533 over the 294. I did have a 533 but switched to a 2600. The challenge is the 533 would have a narrower FOV than the 294 (11x11mm sensor vs 19x13mm).

The 294 is a 4/3 sensor but the resolution is so high that the pixel pitch is 2.3um - so the pixels and full well are smaller.

The 533MC is a great sensor, but physically small. It has the same sensor technology as the 2600 and 6200 and same pixel pitch, so because of the 1" sensor the resolution is much less (9 megapixel). But the read noise is potentially 1/3 of 294, and the full well much larger, so dynamic range would be much greater. It has a square sensor, so framing is less of an issue.

 

 

[Clarkey]

The SVbony 533 is on sale at the moment - apparently the banding is now sorted. Might be worth considering. £561 - but you might have to wait a while....

[Kyuss]

IMX 294 sensor is larger and has a far better full well than IMX 533. Beware though, narrowband with IMX 294 is a real pain in the ***. You need to take dark flats at 4 secs or higher to correct the flats (which will also be 4 secs or higher).

Edited June 19 by Kyuss

[Elp]

I use 183s mainly, first astro camera and still the main one.

I'd advise against the 294, although the sensor size 19 x 13mm is appealing as it's almost apsc, you'll likely get one which suffers from a hideous red/green random pattern after performing a background extraction, you can see the colour even before the operation. This limits how much you can stretch the data to the point it forces you to stop. Initially when looking into the issue I read it was related to flats acquisition, it isn't, it's the glass attached on the sensor which you can do nothing about (there's a lengthy CN forum post about it which came to this conclusion after much testing). I've got a feeling my mono also does it when it shouldn't though I haven't been able to test it much due to the weather.

The 533 produces nice data, the 11 x 11mm sensor might take some getting used to but it depends on your targets and how your optics frame them. Even 10 minutes darks produces next to no amp glow.

Leading to the 183, it amp glows but it's zero issue as the darks calibrate it out. The camera has small 2.4um pixels, but the sensor has resolution so you can bin. The 13 x 9mm size allows for more conventional photo framing.

Edited June 18 by Elp

[Adam J]

3 hours ago, gonzostar said:

Sorry, OSC upto £850max

For that sort of price and with the scope you have i would consider this:

U.K. Astronomy Buy & Sell (astrobuysell.com)

or if you want new:

ZWO ASI 071MC-Pro USB 3.0 Cooled Colour Camera | First Light Optics

The 533 is a small sensor still and the 294mc has too many..."features" for me to recomend. 

The 071 on the other hand is going to give you a wide field of view and pixels that are well matched to your focal length. 

Watch this covering this camera:

IC4592 Blue Horse Head (Konstantin Firsov) - AstroBin

SH2-184 (Almos Balasi) - AstroBin

Cygnus Region w/ Samyang 135mm (Elmiko) - AstroBin

IC434 Horse Head Nebula - Just a dream in full... (Jocelyn Podmilsak) - AstroBin

IC5070 (Joel85) - AstroBin

 

The benefit of a lager sensor can outweigh the benefit of a more modern / sensitive but smaller sensor. As soon as you need to take multiple panels to cover any given target you double your required exposures. But also if you want a given FOV you can do so with a longer focal length and so usually larger aperture scope than with a smaller sensor. 

but then i would also recommend mono over OSC every time. 

 

Adam

Edited June 18 by Adam J

[gonzostar]

Thankyou all for your responses and feedback, very much appreciated. Defo ruling out the 294 sounds to much of a hassle sorting out random patterns. As for the others suggested like the 071, a bit out of range so hope to save some more. For this amount I'd rather go new. Will keep you posted. Like the apples to apples comparison on the lazy greeks clip😁 Cheers Adam J 

[orly_andico]

23 hours ago, Kyuss said:

IMX 294 sensor is larger and has a far better full well than IMX 533. Beware though, narrowband with IMX 294 is a real pain in the ***. You need to take dark flats at 4 secs or higher to correct the flats (which will also be 4 secs or higher).

 

ZWO quotes 1.3e - 2.6e of read noise for the 294 (the lower figure is probably for gain zero) and 14.4K full well (also probably for gain zero)

https://www.zwoastro.com/product/asi294/

and 1e read noise, 50K full well for the 533 which intuitively is correct given the much larger pixels (3.76um vs 2.3um, which is 2.67X larger by area)

https://www.zwoastro.com/product/asi533-pro-series/

[orly_andico]

18 minutes ago, gonzostar said:

Thankyou all for your responses and feedback, very much appreciated. Defo ruling out the 294 sounds to much of a hassle sorting out random patterns. As for the others suggested like the 071, a bit out of range so hope to save some more. For this amount I'd rather go new. Will keep you posted. Like the apples to apples comparison on the lazy greeks clip😁 Cheers Adam J 

 

The 071 doesn't look bad at all

https://www.firstlightoptics.com/zwo-cameras/zwo-asi071mc-pro-usb-30-cooled-colour-camera.html

The read noise appears to be the major disadvantage versus the 533/2600/6200 generation. The pixels are larger which would partly compensate for that (higher read noise means you need longer exposures to get off the noise floor).

I think a used one can be obtained for the stated budget.

I understand the desire to purchase a new one, but (in my experience) these things rarely break. I've bought some old, old cameras - an ST8300, old Apogee Alta, Orion Starshoot Pro; all these were 5-10 years old or more when I had them, and they never failed, I even sold them on. And when you buy a new one, it immediately takes a big hit in value if you try to sell.

 

Also: with the 533 you don't have that many pixels (but the KAF8300 was 8.3 megapixel and many people were happy with that) and a small sensor. If you want a really wide field with the 533, you have to use a really short focal length. I was planning to try the 533 with a Nikon 180mm ED lens, which would give a pretty wide field..

 

Edited June 19 by orly_andico

[Elp]

The new 585 cooled might be an alternative.

I've used the 485 for planetary and dso fine even though it was uncooled, it's practically the same camera but the 585 has the zero amp glow tech and with the cooled one, obviously tec cooling.

The only issue I had was with the 16:9 aspect ratio, you do wish for more verticality like a standard near 3:2 sensor, it however framed well with camera lenses.

[Kyuss]

52 minutes ago, orly_andico said:

 

ZWO quotes 1.3e - 2.6e of read noise for the 294 (the lower figure is probably for gain zero) and 14.4K full well (also probably for gain zero)

https://www.zwoastro.com/product/asi294/

and 1e read noise, 50K full well for the 533 which intuitively is correct given the much larger pixels (3.76um vs 2.3um, which is 2.67X larger by area)

https://www.zwoastro.com/product/asi533-pro-series/

You are refering to ASI 294MM but ASI 294MC is another sensor for some reason with bigger pixel size and full well. (https://www.astroshop.eu/astronomical-cameras/zwo-camera-asi-294-mc-pro-color/p,56499#specifications)

Edited June 19 by Kyuss

[Elp]

I believe the OSC is a binned version of the mono

[orly_andico]

Yes now that you mention it, I do remember that oddity! 

[dunc]

I have used an ASI294MC Pro (the OP wants OSC) for years and as long as you use a tiny offset it's very good.

I've also got a QHY294PROC which can be unbinned to get the full pixel count as in the MM though I've yet to find a way of using the subs as nothing seems to do the special debayering required.  It's a feature of the security camera chip, https://www.sony-semicon.com/files/62/flyer_security/IMX294CJK_Flyer.pdf .

The advantage of the QHY version is access to the overscan areas for BIAS replacement. This is great as every sub has its own bias measured and subtracted, bias is a variable amount in modern sensors which is why you are recommended not to use bias but dark flats instead. For the QHY I use overscan and dark flats and get excellent results. This camera is now discontinued unfortunately 🙁.

HTH

Duncan

[Budgie1]

33 minutes ago, dunc said:

I have used an ASI294MC Pro (the OP wants OSC) for years and as long as you use a tiny offset it's very good.

I think that's the key with the 294MC sensor. I've tried using an offset of 30, which I've seen recommended, but I find it works better with the standard ZWO default of 8. Also, using a gain of 200 with dual-band filters also seems to subdue the colour casting and allows the flats to do their job.

And just to confirm, the colour version of sensor is BIN x2 with a native pixel size of 4.63um. 

My ASI294MC Pro was my first dedicated astro camera and has allowed me to take some good images and has collected great detail. 

[Elp]

If indeed the glass on the sensor is the cause of the 294 colour casting issue then no amount of settings will fix the issue, I normally use it at 120 gain which is where the HCG kicks in with the ZWO version. I'm surprised such a sensor was ever used, I've used at least half a dozen other astro cameras, also daytime camera bodies and none produced an issue like the 294 does (a Sony a7s comes close but it's a separate issue with that one).

I have produced images from the 294, but I've had to keep the stretching very minimal (say 3-4 histogram stretches, when normally I can to 8-10 with other cameras) due to the random colour patterns in the background sky becoming visible.

[Adam J]

22 hours ago, Elp said:

I believe the OSC is a binned version of the mono

No its not there are both IMX294 and IMX492 OSC sensors listed on Sony's website. The sensor is not the same model between the 294mc and 294mm despite the common misconception. 

 

I posted about it above but no one seemed interested. 

 

Adam

[PadrePeace]

11 hours ago, Elp said:

If indeed the glass on the sensor is the cause of the 294 colour casting issue then no amount of settings will fix the issue, I normally use it at 120 gain which is where the HCG kicks in with the ZWO version. I'm surprised such a sensor was ever used, I've used at least half a dozen other astro cameras, also daytime camera bodies and none produced an issue like the 294 does (a Sony a7s comes close but it's a separate issue with that one).

I have produced images from the 294, but I've had to keep the stretching very minimal (say 3-4 histogram stretches, when normally I can to 8-10 with other cameras) due to the random colour patterns in the background sky becoming visible.

I take it you are employing calibration frames in your images? I use the 294MC Pro at 200 gain and 30 offset and with >4sec Flats and dark Flats I’ve never seen any of the mentioned colour patterns stretch through in post. Calibration sorts that entirely. 

[Adam J]

7 minutes ago, PadrePeace said:

I take it you are employing calibration frames in your images? I use the 294MC Pro at 200 gain and 30 offset and with >4sec Flats and dark Flats I’ve never seen any of the mentioned colour patterns stretch through in post. Calibration sorts that entirely. 

This is true, at 200 gain and with good calibration frames it will work fine. I guess the issues is really with beginners getting all that correct. 

Edited June 20 by Adam J

[Elp]

11 hours ago, Adam J said:

This is true, at 200 gain and with good calibration frames it will work fine. I guess the issues is really with beginners getting all that correct. 

As mentioned I have not had a single issue with a 485/183/600D/A6400 so it's NOT through a lack of experience. The 294 simply acts completely different.

I use multiple perspex to dim my flat panel with the panel itself on its lowest setting, from a casual view looking at it like this it doesn't even look like the panel is on. Usually I leave the asiair to calculate the right flats exposure and haven't had issues with other cameras, I've tried seconds long exposures and it still does it, if you do a histogram preview in Siril before and after background extraction the issue is clear to see, in fact it's worse after background extraction even when manually carefully selecting sample points but it's difficult due to the colour cast rendering the operation mostly moot as it's not a linear LP gradient.

I must note the majority of the time when I use the 294 is with an lextreme which I strongly suspect causes an issue but again, haven't had an issue with that and other cameras even daytime camera bodies with the filter on the front of the camera lens exposed to stray LP sources which optolongs don't like.

I'll try and find the CN forum post, it's quite long and people did multiple tests recording values etc, at the end it was concluded as the sensor glass causing the issue.

I don't think it was just one thread as multiple threads exist on the issue, here are two examples:

https://www.cloudynights.com/topic/611039-help-me-with-this-artifact-zwo-asi294/

https://www.cloudynights.com/topic/792863-asi294mc-pro-strange-recurring-color-pattern/

Edited June 21 by Elp

[Adam J]

43 minutes ago, Elp said:

As mentioned I have not had a single issue with a 485/183/600D/A6400 so it's NOT through a lack of experience. The 294 simply acts completely different.

I use multiple perspex to dim my flat panel with the panel itself on its lowest setting, from a casual view looking at it like this it doesn't even look like the panel is on. Usually I leave the asiair to calculate the right flats exposure and haven't had issues with other cameras, I've tried seconds long exposures and it still does it, if you do a histogram preview in Siril before and after background extraction the issue is clear to see, in fact it's worse after background extraction even when manually carefully selecting sample points but it's difficult due to the colour cast rendering the operation mostly moot as it's not a linear LP gradient.

I must note the majority of the time when I use the 294 is with an lextreme which I strongly suspect causes an issue but again, haven't had an issue with that and other cameras even daytime camera bodies with the filter on the front of the camera lens exposed to stray LP sources which optolongs don't like.

I'll try and find the CN forum post, it's quite long and people did multiple tests recording values etc, at the end it was concluded as the sensor glass causing the issue.

I don't think it was just one thread as multiple threads exist on the issue, here are two examples:

https://www.cloudynights.com/topic/611039-help-me-with-this-artifact-zwo-asi294/

https://www.cloudynights.com/topic/792863-asi294mc-pro-strange-recurring-color-pattern/

I was not calling you a beginner it was more of a general statement on the camera. 

[Elp]

2 minutes ago, Adam J said:

I was not calling you a beginner it was more of a general statement on the camera. 

It's fine no issue, just to clarify the experience I've had with other cameras. Maybe I need to try higher gain (like much higher away from the 120 HCG value), but I think I've already done mostly everything with it. I generally only keep it around due to the sensor size, and can sometimes apply synthetic flats to reduce the issue.

I've also standardised my flats set, dimmable panel and I think I can get away with one sheet of 10mm thick black colour perspex (before I was using four sets of different colour perspex from white opal through to grey then black 2mm sheets).

[Budgie1]

2 hours ago, Elp said:

Maybe I need to try higher gain (like much higher away from the 120 HCG value), but I think I've already done mostly everything with it.

Using the Askar Duo-Band or the L-eNhance filters I have for my ASI294MC Pro, I always use a gain of 200 and this seems to work. I only use 120 gain with a UV/IR filter for broadband imaging.

It's also worth trying the offset at 8, instead of 30, as I found it gave a cleaner image. 

For my flats, I use the APT auto-flats tool and set the ADU at 32,000 and try to get the exposures to around 2 seconds. To subdue the flats panel, I normally add 2-4 layers of white t-shirt.  

Do some experimentation, the 294 may surprise you.