Is 294 cameras still good nowadays?

Hi, I can only refer to the amp glow issue and yes, it is fully fixed taking a good set of darks. Now I have a completely different criticism and, it is regarding humidity, it has internal pills that must be replaced and baked to be re usable. The other issue is a funny X red shaped image that comes from that sensor, and with some flats can be detected. There is a thread on this in cloudynights if you are interested. So, in general, for me is a good camera, SvBony has a model based on the same sensor (IMX294) but with an external control of humidity.

Despite been old sensors I love them and have the 294 Color and the 1600 mono. To be honest I hate APS-C sensors. Too big and not so forgiving in most good optical systems.
I mean, there's a lot of good telescopes in our days, but for a good corrected field in an APS-C size, they are not cheep. An optical expert use to say to me that if you go with bigger sensors, you'll need bigger apertures which leads to a better corrected optical systems with not so forgiving tolerances, bigger filters, bigger mounts.. and that resumes to a bigger wallet. 

This is one of the main reasons that I still love those MFT sensor sizes. If you do the correct things like calibration, maintenance and use the recommended settings, you'll get great results.

Regards,

Cesar

I have the ASI294 and the ASI2600 (more modern low noise no amp glow), both Mono versions. 

Both are capable of exceptional images. Calibration is more important with the ASI294 to get rid of amp glow etc, but I do that even with the ASI2600 so am not saving much.

I find the large pixels of the ASI294 and the ability to use half size pixels (unbinned) makes it very flexible.

In many cases with some optical systems going beyond m43 is asking for trouble and you will crop anyway. For galaxy imaging in my SCT its a good fit.

The smaller size of the ASI294 sensor means I can use cheaper 31mm filters whereas need 36mm for the ASI2600… this matters as the 31mm astrodons are a lot cheaper.

Obviously if I want wider the ASI2600 is better, but for many purposes I prefer the ASI294. Dont think anything has replaced it.

Claudio Tenreiro:
Hi, I can only refer to the amp glow issue and yes, it is fully fixed taking a good set of darks. Now I have a completely different criticism and, it is regarding humidity, it has internal pills that must be replaced and baked to be re usable. The other issue is a funny X red shaped image that comes from that sensor, and with some flats can be detected. There is a thread on this in cloudynights if you are interested. So, in general, for me is a good camera, SvBony has a model based on the same sensor (IMX294) but with an external control of humidity.

The one i have is from QHY, it is an amazing brand and design quality, so i believe what you are talking about is from ZWO model, not with QHY, hope i am correct.

Thank you

Observatório Astrográfico do Boqueirão:
Despite been old sensors I love them and have the 294 Color and the 1600 mono. To be honest I hate APS-C sensors. Too big and not so forgiving in most good optical systems.
I mean, there's a lot of good telescopes in our days, but for a good corrected field in an APS-C size, they are not cheep. An optical expert use to say to me that if you go with bigger sensors, you'll need bigger apertures which leads to a better corrected optical systems with not so forgiving tolerances, bigger filters, bigger mounts.. and that resumes to a bigger wallet. 

This is one of the main reasons that I still love those MFT sensor sizes. If you do the correct things like calibration, maintenance and use the recommended settings, you'll get great results.

Regards,

Cesar

I am trying to hold longer on my 4/3" sensors because i have small size filters that i will never sell or give up, Astrodon/Chroma 1.25" are amazing quality, can't use them with APS-C, so it is like the issue of 4/3" is less than issues of new APS-C with 1.25" in my mind, i leave affordable price 2" for APS-C, even with 36mm i feel that smaller sensor is more forgivable.

I have the ASI294 and the ASI2600 (more modern low noise no amp glow), both Mono versions. 

Both are capable of exceptional images. Calibration is more important with the ASI294 to get rid of amp glow etc, but I do that even with the ASI2600 so am not saving much.

I find the large pixels of the ASI294 and the ability to use half size pixels (unbinned) makes it very flexible.

In many cases with some optical systems going beyond m43 is asking for trouble and you will crop anyway. For galaxy imaging in my SCT its a good fit.

The smaller size of the ASI294 sensor means I can use cheaper 31mm filters whereas need 36mm for the ASI2600... this matters as the 31mm astrodons are a lot cheaper.

Obviously if I want wider the ASI2600 is better, but for many purposes I prefer the ASI294. Dont think anything has replaced it.

First, nice gallery and beautiful images from both cameras, good job!

Second, all cameras can produce exceptional images, we still remember the era of CCDs, i never used those but i used to see results here from CCDs mainly premium observatories, so i assume even current several years CMOS sensors are capable of fantastic images once used properly and correctly.

This is one of the reasons i am keeping 294 mono, i can use it with different scopes for better sampling, i even can think about using it for solar without buying different pixel sizes cameras, i just felt that people are giving up this sensor in favor of new models of sensors, which made me to question if it is any good sensor at all to give up that fast.

I have Astrodon/Chroma 1.25" filters, i will never sell them or give up, so i have to keep smaller sensor to my collection, i don't like that 1" from 533, so i didn't have another choice, unless i use 1.25" with APS-C and then crop a lot, not a good idea in my mind.

I bought 571 for two reasons, one because it is newer with better performance, and second to have wider FOV, but the pixel size is kind of not matching perfectly for some scopes, so if sampling is that much important then i have to use a camera to match that, and 294 mono is like 2 in 1 camera for that purpose.

My QHY294C PRO's red bayer filter has strange pattern on the picture which is only visible when  red light reflects of the sensor. It shows up in all my lights. With narrowband filters the pattern perfectly calibrates out with flats but I couldn't find a way to calibrate them with broadband filters yet.

Except this issue, dark frames works perfectly and I do not have any issue with dew on the sensor.

I use and used the QHY-Models, never had problems with humidity. All my pictures were made with the Mono-Version fix in an observatory, the OSC I use on a mobile setup.
No problems with calibration if you have a good dark library.
The 294M from QHY can also be used with unbinned 2.4um. The 294M is not so good in blue as the 571-Chip, but much better in red.
I can recommend both cameras.

I use a ZWO AIS294MM pro as well as the QHY 294M. They are my work horses and both have pros and cons. The cooling system on the ZWO is in my case better than that of the QHY. I reach lower temperatures with the ZWO easily but I also have some dew problems with this camera. But they only show up at really extreme cooling settings. I tried to fix them and even put new tablets in, but it's not 100% solved. What I did instead is cooling to a somewhat higher temperature (still low enough) and it works really well. During the colder seasons, all is fine.

The QHY on the other hand has this external desiccant container which I leave on all the time. It is working exceptionally well and if I issue some dew, the problem is fixed within a minute or two. This is much easier than dealing with the ZWO and can be done even with the camera attached to the telescope. The same is true for my QHY 183c. I love this system so much, that I built myself some more containers for my Touptek cameras as wel (I know you can even buy them)l. Sadly the ZWO did not offer an opportunity for attaching something similar.

I got my ZWO 294MM kind of early in this hobby. Even with less experience, I never had any problems with calibration frames and amp glow. Every year, I take a new dark library and reuse the frames most of the time. I am looking for a third camera with the same sensor for my third rig as well. There I currently use a ZWO 183MM Pro. This camera runs now for about 5 years. I never had to do any maintenance on this one ever. It still runs perfectly well from day one until now. I hoped this for the 294MM as well, but you can't have everything, can you?

I am not sure if I really want to spend my money on a ASI2600 or similar. I am so happy with the 294s. Their pixel size (11MP or BIN2 mode) fits all my telescopes really well and I am at a sweet spot at sampling here.

Of course there are better cameras out there these days. This is how technology works. But I don't really mind. No need to replace something now. It would be just a waste of money (if there even exists such thing in our hobby, I know :cool-1.

Tareq Abdulla:

Ron:
I agree with Claudio regarding the humidity, however, I don't believe it is a chip issue, rather a manufacturing issue.  I purchased an ASI294MM Pro in September of 2023 and it already is showing severe dewing on the sensor less than a year after purchase.  Following ZWO's instructions, microwaving did not reactivate the dehumidifying tablets.  Baking them at 200F for 2 hours also did not reactivate them, either.  I'm concluding that either the camera is poorly sealed (yes there is an o-ring that should provide a good seal) or the tablets do not contain enough desiccant.  

Aside from that, I like the camera.  The amp glow is completely removed by darks.  There is a weird flat pattern particularly noticeable in the reds (broadband red, H-alpha, S-II) but it also is not noticeable after calibration.

HTH,
Ron

That issue could be only with ZWO camera, actually i read more issues of design quality upon ZWO cameras rather than another manufacturers, for example QHY has better design quality, only cons with QHY is their drivers which is almost ok with me, i manage software WAY much better than body design anyway, in fact i have that dew issue with my QHY163M the old model, no issue with ASI1600mm, i will test QHY294M more to see if i will have that issue or not.

Indeed, I did refer to the ZWO ASI294 MC Pro

I have two 533's, a 2600, and now both the 294MM and MC, and they all have their place and use. I like the 294s for their high QE, full well depth, and large pixels. They can be used with less expensive 1.25" filters as well. The larger pixels are a nice match for my Edge HD, and in bin1 they are perfect for my Redcat 51. They have issues, but as long as you shoot the proper calibration frames they are a terrific camera. If you need smaller pixels to match with your telescope then go with a 2600 or 533 if you can live with a square aspect ratio and narrow field of view.