
Is the QHY183c a good choice for me?
#1
Posted 14 May 2022 - 07:59 AM
The 183c seems like a good fit but I’m skeptical as to why everyone doesn’t have one at $700.
I know they are small pixels but it gives me a pixel scale of 1.15. I probably won’t be upgrading the scope for a while as I dropped a chunk on a new mount.
Any issues with that camera? Any funky calibration tricks it needs?
Thanks for any info!
Clear skies
#2
Posted 14 May 2022 - 08:52 AM
The QHY183 has been out a while, and yes, it's a very good price, but most people on the beginning level seem to stay away for a couple of reasons.
1. The buy the ZWO version for compatibility with the Asiair pro mini computer, which only accepts ZWO cameras and DSLRs
2. Amp glow. With taking darks, the amp glow calibrates out perfectly, but regardless, it scares some people.
3. QHY had some driver issues in the past
4. Small well depth - This camera is great for short exposures , although with narrowband filters, i was taking 180-240 shots.
I owned one for 1 year, but I sold it, because i was funding another purchase, but lately I miss it. It has a small sensor array, perfect for 300--1000mm focal range.
Here is an image taken with my Orion newtonian and QHY183C last year december: doing 20 second subs
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#3
Posted 14 May 2022 - 09:04 AM
What does the small well depth do? I’m in bortle 6 so I don’t take long subs 30s-180 ish.
Does that limit the dynamic range? If so is it something I’ll actually see?
Thanks!
#4
Posted 14 May 2022 - 09:15 AM
Doesn’t seem like down sides that affect me. No asi air, glow is fine, I take calibrations.
What does the small well depth do? I’m in bortle 6 so I don’t take long subs 30s-180 ish.
Does that limit the dynamic range? If so is it something I’ll actually see?
Thanks!
Small well depth means that the camera can only take certain amount of photons until the image start to over saturate and the light captured start to spill over to other pixels- or what it looks like visually on the images.
Basically it's easy to over expose images. In broadband (no narrowband filters) I was doing gain 0 . The camera has its own UV/IR cutting sensor window, so no extra filters needed.
With narrowband, you have to experiment. between various gains settings , I can't remember what I used often, but it might have been gain 10 or 11.
Here and image I took with narrowband filter last summer. I can't remember what gain settings I used:
Edited by unimatrix0, 14 May 2022 - 09:16 AM.
#5
Posted 14 May 2022 - 09:25 AM
I’ve got a WO Z73 scope, I’m currently using a dslr and I’d like to move to an astro cam.
The 183c seems like a good fit but I’m skeptical as to why everyone doesn’t have one at $700.
I know they are small pixels but it gives me a pixel scale of 1.15. I probably won’t be upgrading the scope for a while as I dropped a chunk on a new mount.
Any issues with that camera? Any funky calibration tricks it needs?
Thanks for any info!
Clear skies
The big deal first. Is $700 the price for an uncooled version? This is a bad place to save a few hundred dollars. An uncooled astro camera is little better than a modded DSLR. Cooling is a major reason astro cameras are better than DSLRs.
I have both 183s. Purchased for a C8 RASA.
I've moved on to 2600s.
It's a decent camera. Amp glow is a problem some people can't seem to shake. I've NEVER had it. I do bias, flats, darks. Shortcutting by omitting any of those is risky. It's easy to process badly, and get amp glow.
The small pixels are signal to noise ratio challenged, decent total imaging time compensates.
A 533 is a nice camera, and significantly easier to live with. People here worry too much about numerically larger image scales. This is 2.8. I won't post the usual CN jpg, the image is sharp enough that that blurs it.
https://www.astrobin.com/367734/C/
Edited by bobzeq25, 14 May 2022 - 09:34 AM.
#6
Posted 14 May 2022 - 09:43 AM
I generally try to get double digit hours in subs so it sounds like I can get the s/n ratio livable.
I’d looked at the 533 but it’s a little more money and I’m not really sold in the square sensor. Of course I could always crop.
The wife wants the dslr for a project so I’ll probably jump in a 183c since they are in stock.
Thanks guys!
#7
Posted 14 May 2022 - 09:48 AM
I've never seen blooming or smearing in any of my CMOS cameras. My understanding has always been that CMOS cameras do not bloom/smear because they convert charge to voltage at the pixel level. So, that's the last thing to worry about when selecting the 183 camera. So the FWD simply determines the maximum signal that the pixel can hold as far as I know.
As Bob said, get a cooled camera. Your images with thank you (figuratively).
Rgrds-Ross
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#8
Posted 14 May 2022 - 09:54 AM
As Bob said, get a cooled camera. Your images with thank you (figuratively).
Rgrds-Ross
The OP is talking about the cooled camera . The QHY183C is sold for $700 and I've seen it as low as $600. That's the cooled version.
#9
Posted 14 May 2022 - 10:04 AM
I’ll go check the specs on the FF but would like confirmation as usual.
Thx!
Edit: I just checked and the FF has m48 threads, do I also order an adapter to go from m48 to m42? Will I still meet my backfocus?
Looking it up I need 55mm - camera back focus (17.5)= 37.5 of spacer in front of the camera. Agreed?
Edited by Desertanimal, 14 May 2022 - 10:20 AM.
#10
Posted 14 May 2022 - 10:18 AM
Yes, but you will want to buy extensions. I used a step-up, since my flattener was M48.
So i got a M42 to M48 adapter/extension and depending on the flattener requirements (usually 55mm) I added enough M48 extensions.
The QHY183C has a 17.5mm flange distance, so I had to add 37.5mm extension pieces to get to 55mm.
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#11
Posted 14 May 2022 - 03:17 PM
No calibration "tricks" - just be consistent about matching darks to lights. People here usually forget that the well-depth figure that actually matters is well depth per unit area. The 183 sensor does have less well depth than many other sensors, but It's not as big a difference as looking at the non-normalized numbers would make you think.
The ZWO 183c does not have a built-in UV/IR cut (but has threads to mount a 1.25" filter right onto the camera). The QHY183C does have a UV-IR cut filter,
It's the only camera I use, and I am still happy with it. But it's not for everybody. Make sure you spend some time on astronomy.tools to see if you're comfortable with the small field of view, compared to some other options.
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#12
Posted 14 May 2022 - 06:55 PM
If you add an IR/UV filter and you plan to use a reducer or flattener that has a precise spacing requirement be aware that you will need to increase the spacing by 1/3 of the thickness of the filter. That's true for a mono or color camera.
I prefer to use Telescopius to look for targets. I can describe any imaging system fully and get excellent feed back about target timing and field of view.
Rgrds-Ross
#13
Posted 14 May 2022 - 11:11 PM
Excuse my ignorance but what does the IR/UV cut filter do for me? When does one need to use it?
Edit: I did read a post of the same question and it’s to prevent bloat in the stars. Sounds good.👍
Thanks!
Edited by Desertanimal, 14 May 2022 - 11:36 PM.