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Old 23-11-2017, 07:11 PM
Andrew_Campbell (Andrew)
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Cooled CMOS advantages

Sorry for the potentially thick question, folks. I'm thinking of getting a cooled CMOS camera (ZWO 1600 Mono Pro or the like). Would I be correct in assuming that I can run a packet of darks, etc, at a set cooled temp, and so long as the image I'm taking is at the same temp and exposure length, can roll out the same darks time and time again?

Ie, have a pre-generated folder of 500x 30 second -10 deg C, and throw them into every 30 second -10deg c light capture I use?

Too simplistic?
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Old 23-11-2017, 07:17 PM
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Camelopardalis (Dunk)
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Yup - simple as that - I've found the 1600 to be very reproducible wrt darks.
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Old 23-11-2017, 07:26 PM
Andrew_Campbell (Andrew)
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Wow, that's fantastic. Cooled cams that you can set to a specified temp are worth it just for that reason alone.
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Old 23-11-2017, 07:30 PM
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Yeah just be warned that not all sensors are equal...some of the Sony family of sensors have pretty horrendous amp glow, which is much less predictable and tricky to calibrate out. I have the ASI178 mono cooled with such a sensor and it can be a bit of a headache.

The 1600 I've found to be a model citizen.
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Old 23-11-2017, 08:07 PM
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Atmos (Colin)
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I’ve found the ASI1600 to be easy to calibrate as well, it’s certainly what you want.
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Old 23-11-2017, 08:10 PM
glend (Glen)
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Take some time to build a Dark Library, and honestly you do not need 500 subs to build a Master Dark. The idea is to pre-create a number of Master Darks for your usual shooting situation; for example i shoot a lot of 5min narrowband subs at the 1600s Unity setting (Gain 139, Offset 21), with the sensor temp at -25C, so i have a Master Dark built to match. I don't worry about shooting alot of Dark subs, i think most of my Master Darks are using around 30 subs. I have Master Darks for all of my normal sub shooting configurations, for example if i am shooting high gain (200), i will pick the high gain Dark that suits, same with the max well depth setting of Gain 76, etc. Once you have built that Master Dark Library you only need to pick that one Master when doing your calibration.
Note the same applies to Bias Frames, but simpler in that they are all 0 seconds (if your using SGP you can select 0 second Bias subs, but some software does not permit a 0 second bias sub). A 0 second Bias is simply an instant dump of the idle sensor.
BTW, there are folks who never use Darks with the 1600, they may use Dark Flats, or nothing at all, its that clean. If your shooting alot of short sub LRGB then any AMP Glow will be undetectable. Its only when you get into long narrowband subs do you need to think about AMP Glow. The new Pro model with the DDR chip is suppose to significantly reduce long sub AMP Glow, but for most early model owners it was never an issue anyway because it calibrates out with Darks. I suppose with the Pro version there maybe more of an argument for ignoring Darks altogether, but i will stick with using them.
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Old 24-11-2017, 05:54 PM
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Good to see you join the 'dark' side Andy, or at least considering!

Amp glow is not an issue even for us first adopters, calibrates out easily. Short subs can cause no signal to be registered, again easily corrected with good darks.
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Old 30-11-2017, 12:29 PM
Andrew_Campbell (Andrew)
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Thanks, gents. All the reports and reviews of the ASI1600 Mono Pro seem to agree on its value as an AP camera. Now I just need to get my head around whether to buy one of the kits with the LRGB / NArrow filters and a manual / electronic filter wheel. Decisions decisions...
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Old 30-11-2017, 12:51 PM
glend (Glen)
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Quote:
Originally Posted by Andrew_Campbell View Post
Thanks, gents. All the reports and reviews of the ASI1600 Mono Pro seem to agree on its value as an AP camera. Now I just need to get my head around whether to buy one of the kits with the LRGB / NArrow filters and a manual / electronic filter wheel. Decisions decisions...
There are other filter wheel options, the QHY wheels allow screwing directly to the ASI1600. I would suggest going with the 36mm filters, and consider quality filters. Electronic filter is a necessity imho, it allows you to program an imaging sequence in an app like SGP and just let it run and software switch the filter. Its pretty neat to have your entire nights imaging automated, allowing you to sleep if you wish.
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Old 30-11-2017, 07:25 PM
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ZeroID (Brent)
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I bought the 1600mm-c mini kit with the 1.25" filters all from ZWO. They are good for scopes down to f5 as they are very close to the sensor. It's been an interesting learning experience so far. Nothing wrong with the gear but coming to grips with the added processing and imaging requirements.
Still haven't produced anything I'd dare show here yet but getting the hang of it slowly.
Clouds haven't helped much either...
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Old 30-11-2017, 09:22 PM
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I use the mini EFW with 1.25" filters and don't see any vignetting at f/5.5. Wish I'd bought the 8-position EFW though as 5 positions isn't enough for LRGB + narrowband. It is a lot bigger though.
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Old 02-12-2017, 07:14 PM
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Go on put them up. I put up my pics warts and all. The comments have been really helpful !

Quote:
Originally Posted by ZeroID View Post
I bought the 1600mm-c mini kit with the 1.25" filters all from ZWO. They are good for scopes down to f5 as they are very close to the sensor. It's been an interesting learning experience so far. Nothing wrong with the gear but coming to grips with the added processing and imaging requirements.
Still haven't produced anything I'd dare show here yet but getting the hang of it slowly.
Clouds haven't helped much either...
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Old 03-12-2017, 08:49 AM
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ZeroID (Brent)
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Go on put them up. I put up my pics warts and all. The comments have been really helpful !
Nah, I need to reprocess to get rid of some alignment issues during the image processing. Quite happy with the result re colour and depth but I want my stars to all be single dots, not smeared RGB blobs .
It's the result of demounting the camera after each session and not getting a perfect match next time. I'd rather not leave the camera out in a tin shed Ob for some dodgy character to walk off with it.
I'll find a solution.
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