Mono Camera for EAA

[PeterC65]

I currently use an IMX585 OSC camera for EAA. I’m considering getting a mono camera to compliment it and wanted some feedback on my reasoning and possible mono camera choice.

A mono camera will be three times more sensitive than the equivalent colour camera due to the absence of a Bayer Matrix, so I would be exchanging colour for more detail.

The objects that would benefit most, and suffer least, will be those that are faint and don’t exhibit much colour. I’m thinking galaxies, reflection nebulae, and maybe planetary nebulae, not so much larger emission nebulae. So mostly smaller fainter objects for which I would be using a longer focal length, wider aperture scope, an 8” F5 Newtonian in my case.

I don’t want to spend any more that I did on the IMX585 camera. Camera price is strongly correlated with sensor size, and mono cameras are more expensive than their colour equivalent. So I’m looking for a mono camera with a sensor that is a little smaller than the IMX585, but not so small that plate solving starts to fail with the 8” Newtonian.

Sensitivity also increases with pixel size, but I can make bigger pixels by binning smaller ones, both to increase sensitivity and to match the scope. So for a given sensor size it would be best to choose a camera with small pixels so that binning allows a range of larger pixel sizes (2µm, 4µm, 6µm, 8µm being better than just 4µm and 8µm for example).

With all this in mind I’m thinking that an IMX678 mono camera would be a good choice, such as the QHY5III678M. It has an 8.8mm diagonal sensor (12.9mm for the IMX585), 2µm pixels, 4K resolution (so enough pixels to bin without too much pixelation), and no amp glow.

Does this make sense? Am I missing anything? Are there other cameras worth considering? What do owners of IMX678 mono cameras think of them?

 

[Richard N]

This topic hasn’t quite gone viral yet. 

[PeterC65]

41 minutes ago, Richard N said:

This topic hasn’t quite gone viral yet. 

No! But thanks for replying.

There are only a few of us on SGL doing EAA so I wasn't expecting many replies. I keep posting about EAA in an attempt to increase our numbers. I did also post on CN where EAA is more popular and have had some replies there.

What I've learned so far is that mono should show me more detail but I won't really know the difference until I try it. It's also been mentioned that the extra sensitivity of a mono camera could be "spent" on using a narrow band Halpha filter (or maybe an L-Ultimate) for better views of faint emission nebulae, which is something I hadn't considered. I find that with my colour camera I can't use really narrow band filters as they require much longer exposure times to get enough photons to the sensor.

 

[PeterC65]

59 minutes ago, PeterC65 said:

maybe an L-Ultimate

Maybe an L-eXtreme. I've just looked up the price of the L-Ultimate (expensive), and I think 3nm may be too narrow anyway, even for a mono camera, doing EAA.

 

[Chris-h]

I sometimes do EAA with my Samyang 135. I have the 585 as well, and I don't think you lose out that much to mono with this sensor. I also use it with my Altair Dualband filters. These work well even at f/2! The stars are horrible though, so starless all the way!🤣

Here are NGC1499 (30x30sec) at F/2 And M42 (106x30sec) at f/2.8. Gain 300

Edited March 8 by Chris-h

[Chris-h]

Oh btw, Sony does have the 585 in mono as well. I think ZWO are looking into it, so might be worth waiting a bit

[Artik]

On 01/03/2024 at 14:35, PeterC65 said:

Does this make sense?

Absolutely. I myself use Mono camera (Meade based on IMX178) frequently, especially on objects like galaxies.

Honestly being mono it gives more feeling of visual like.

Here few days ago my short session. 

SVBony sv501p 60/400 achromat, AZ GTi az-mode, Meade IMX178 Mono, IR/UV cut, software Android tablet with OpenLiveStacker

Most of them around a minute or so (because I have a very little patience) - also some absolutely need more time 🙂 

 

[PeterC65]

33 minutes ago, Chris-h said:

Oh btw, Sony does have the 585 in mono as well. I think ZWO are looking into it, so might be worth waiting a bit

Yes, I have that on my radar. I think that would be the ideal solution.

 

[PeterC65]

10 minutes ago, Artik said:

Absolutely. I myself use Mono camera (Meade based on IMX178) frequently, especially on objects like galaxies.

Honestly being mono it gives more feeling of visual like.

I think it's hard to know without doing a like for like comparison. I get much more detail than your images show in M65/66 and M82 for example, but you're using a 60mm refractor which is at the smaller end of my scopes. I would normally use the 6" or 8" for these objects. Here is M82 for instance with the 8" and x1.7 Barlow ...

I was using darks and flats and the stack is 28 x 15s exposures. This is what I saw on the night, with no post processing.

The question is what would this look like with a mono camera instead? I would loose the colour which I think is a problem for an object like M82, but not so much for the fainter galaxies of which there are plenty.

I agree with your point about mono being more like visual. I occasionally wind the colour saturation down to zero with the colour camera to see what the object looks like in mono but that doesn't also give me the extra sensitivity that I should get from a mono camera.

 

[Artik]

Obviously 150mm or 200mm is way better. I sometimes use my 102/660 scope on galaxies and results are obviously way better.

Also I use mostly 5s subs.

I just wanted to show an example. I find myself using mono more than my color camera because both of speed and imx178mm is better than my asi224mc