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Choice a new camera for a dual rig setup.

Equipment CMOS Buying Advice
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Pranalabs avatar
Pranalabs avatar
Hi,
I am deciding for which camera to purchase in conjunction with my William Optics GT81 WIFD reduced to 0.8x (382mm f.l.).
Whereas, in parallel I have a WO FL120 @0.8x with a Poseidon M Pro - IMX571 Mono (1.24"/px and FOV 2.16°x1.44°) with which I am doing very well in relation to my seeing.
I have two possible choices:
1) a Poseidon C Pro (IMX571C) with which I would have a wide field of 3.52° x 2.35° and a resolution of 2.03"/px
   PRO:
   - Wide field compared to FLT120 for extended targets directly in color (with an option for FLT120 in parallel but with mosaic for narrow band and/or luminance)
   - I could use the GT81 (to do RGB as if it were a Bin2 on the FLT120 (I know, it's not exactly like that because of the Bayer Matrix - [25% R, 50% G, 25% B] )
   - No filter to buy (at least at first)
   - 16 bit camera
   - no ampglow
   CON:
   - Resolution of 2"/px which on an OSC might be penalizing since I am used to it well with the FLT120
2) An Artemis M Pro (IMX492 Bin1x) with which I would have a wide field of 2.87° x 1.95° and a resolution of 1.25"/px. Pretty much the same resolution and a slightly wider field than the FLT120 (to be cropped).      
   PRO:
   - same resolution and compatible FoV between the two setups
   - more sensitive mono camera
   - possibility of reversing the cameras between the two instruments
   CON:
   - cost of 36mm wheel and filters (at least LRGB)
   - camera 12bit (bin1) and 14bit (bin2)
   - ampglow (perhaps not a problem on mono?  I have no experience with this)
   - I lose the convenience of the OSC in case I need to make a mobile short-focal setup
   - large files in bin 1x (46MPx).

I would like to exploit the two instruments in parallel to make twice as many images per single session and maybe avoid some mosaics.
What do you recommend?

Thanks
GT
V avatar
V avatar
I would personally say to go with the Poseidon C, and use the Color data as L, and use the stars for narrowband data.
Dunk avatar
Dunk avatar
I'd also go with the Poseidon C for the same reason (I actually have both Poseidon's and have done as @OklahomAstro  suggests).

Another advantage is that now you have an OSC camera for those times you don't have time/can't be bothered to shoot mono.
Bray Falls avatar
Bray Falls avatar
Mono, not being able to collect good data with one of the scopes during the brighter part of the moon phase is worse for overall efficiency. The cost and complexity are worth the extra quality data you will be able to shoot.
Dunk avatar
Dunk avatar
Bray Falls:
Mono, not being able to collect good data with one of the scopes during the brighter part of the moon phase is worse for overall efficiency. The cost and complexity are worth the extra quality data you will be able to shoot.

Spoken like somebody who has dark skies and plenty of time ;-)
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Julian Shroff avatar
Julian Shroff avatar
Dunk:
Bray Falls:
Mono, not being able to collect good data with one of the scopes during the brighter part of the moon phase is worse for overall efficiency. The cost and complexity are worth the extra quality data you will be able to shoot.

Spoken like somebody who has dark skies and plenty of time ;-)

The irony lies within the fact, that Mono should be the choice especially if you do not have dark skies and plenty of time, because it will give you a better image in less time.
Especially considering that the reduced F4.7 isn't the fastest focal ratio, which will further aggravate the "issues" OSC-Cameras are dealing with.
D. Jung avatar
D. Jung avatar
A bit tangential to the op question. I just did the switch from color to mono. Based on plenty of discussions and back of the envelope calculations the general conclusion usually seems to be that mono has only a small advantage over color comparing time/effort/outcome. Yet comparing the SNR of the mono to my color images (same filter, same optics), I find that the mono data is so much better that I wonder where the flaw is in those calculations. 1h mono easily matches several hours (>5h and more) color. Maybe the SNR degradation from the debayer process is hugely underestimated.
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Pranalabs avatar
Pranalabs avatar
Hi,
first of all, thank you for your answers.
You have basically summarized my dilemma!

Now, taking into account that I live under a rural Italian sky (Bortle 5/6) and good nights are actually quite limited (surely Bray Falls beats me hands down :happy-4smile I should opt
for mono.

The question is: the IMX492 (bin1x) in 2024 still a sensible choice? Or are we talking about something far removed from the performance of the IMX571 Mono?

I mean, would staying on a resolution of 1.2"/pix on both setups then penalize me because the camera with IMX492 is inferior in terms of dynamic range (12 bit vs 16 bit) etc ?

Thank you very much
G
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Julian Shroff avatar
Julian Shroff avatar
Pranalabs:
Hi,
first of all, thank you for your answers.
You have basically summarized my dilemma!

Now, taking into account that I live under a rural Italian sky (Bortle 5/6) and good nights are actually quite limited (surely Bray Falls beats me hands down ) I should opt
for mono.

The question is: the IMX492 (bin1x) in 2024 still a sensible choice? Or are we talking about something far removed from the performance of the IMX571 Mono?

I mean, would staying on a resolution of 1.2"/pix on both setups then penalize me because the camera with IMX492 is inferior in terms of dynamic range (12 bit vs 16 bit) etc ?

Thank you very much
G

You basically have three choices when it comes to monochrome cameras. IMX533, IMX492 and IMX571. Given that your telescope is used at F4.7 you can definitely get away with 3,75 micron Pixels, 2,4 might have me worried in terms of noise. I doubt that the benefit in resolution is worth the SNR lost. The loss in dynamic range is slightly noticeable, but as long as you don't overexpose you should once again be fine at F4.7. If you can afford it, obviously the IMX571 would be a high quality future proof sensor. Otherwise, if you really want the improved image quality, I would consider the smaller but very clean IMX533 sensor. I would probably prefer it over the 492, given its record of issues with flats & amp glow.
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