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Old 05-12-2020, 05:14 PM
Zuts
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Well depth

Hi,

The 2600 MC has an advertised well depth of 50,000 -e, while the 1600 MC has 20,000 MC. However the recommended unity gain for the 1600 MC is 139 where the well depth drops to around 3,000 -e. The 2600 MC has well depths of 50,000 -e at gain 0 and 20,000 -e at gain 100.

I run my 1600 MC at the recommended gain of 139, should I go much lower to increase well depth or will it just increase the length of subs I have to take?

Also for people with the 2600 MC do they run the gain at 0 or 100 when doing DSO unfiltered shots?

Specs for ZWO 2600 MC
https://astronomy-imaging-camera.com...00mc-pro-color

Specs for ZWO 1600 MC
https://astronomy-imaging-camera.com...asi1600mc-cool
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Old 05-12-2020, 05:55 PM
Startrek (Martin)
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Paul,
These 2 cameras are entirely different in performance as far as specs are concerned (I can only comment on my 2600MC)
The 2600MC is a high performance low read noise camera and is recommended to be pushed towards full well which results in the highest dynamic range at the expense of only a small increase in read noise
I’ve used my 2600MC at both lowest read noise and highest dynamic range (Ascom) under Bortle 8 (Duoband filtered and unfiltered) and Bortle 3 skies with short and long subs
To be honest my best images have been using Highest Dynamic Range ( Gain 0 offset 50 ) with short ( 60 to 90 sec subs ) and long subs ( 180sec to 300 sec ) at both imaging locations
ZWO recommend to use HDR ( gain 0 ) in both light polluted and dark skies and as far as I’m concerned they are spot on !!!
Cheers
Martin
PS: I run my camera at - 12C in the summer months ( maxed out ) and -15C during winter months ( I can go lower but don’t really need to) At both these temperatures, dark current is extremely low and almost negligible
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Old 05-12-2020, 09:43 PM
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The_bluester (Paul)
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I run my 2600 at gain 0 and after last new moon I am routinely doing 600 second exposures. I run mine at -10 degrees as it should be able to maintain that year round and it saves me having to have dark libraries for multiple sensor temperatures.

I have not yet seen any reason to play with higher gain, maybe to try for short subs on bright targets, but the extended absolute range the 16 bit ADC gives was one of the reasons I was keen on this camera and I hesitate to hand that back by raising the gain. In theory the read noise of my 2600 at 0 gain (Closest to unity, all gains are above unity for the 2600) is around double that of my ASI294 at unity (At which point that camera has 16Ke full well) but sub for sub it certainly does not look like it has twice the read noise.
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Old 06-12-2020, 01:05 AM
Zuts
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Quote:
Originally Posted by The_bluester View Post
I run my 2600 at gain 0 and after last new moon I am routinely doing 600 second exposures. I run mine at -10 degrees as it should be able to maintain that year round and it saves me having to have dark libraries for multiple sensor temperatures.

I have not yet seen any reason to play with higher gain, maybe to try for short subs on bright targets, but the extended absolute range the 16 bit ADC gives was one of the reasons I was keen on this camera and I hesitate to hand that back by raising the gain. In theory the read noise of my 2600 at 0 gain (Closest to unity, all gains are above unity for the 2600) is around double that of my ASI294 at unity (At which point that camera has 16Ke full well) but sub for sub it certainly does not look like it has twice the read noise.
That's interesting thanks. I run my camera at -10 as well for the same reason. Then i thought it's actually summer now and it s only running at about 40%, so maybe i can go to -15 all year round.

Thinking again, coz I have had a few red wines, it only takes a few hours to get a good dark library so why not -30 for winter?
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Old 07-12-2020, 10:30 AM
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I suppose the question would be if there is any gain to be had from it. In the case of the ASI2600 I decided it was marginal enough improvement going from -10 to -15 that I would just stick to -10.

I just shot 50 X 900 second darks for mine. A recent test showed that the camera would respond well to 900 second exposures so I better get ready to use them! Handy for really dark stuff or if I put a HA filter in the train.
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Old 07-12-2020, 08:16 PM
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The answer is provided by ZWO in their specs...at -10C, the thermal noise is roughly 0.0006e per second.

Simply multiple that by the number of seconds

The different between the two temperatures is negligible compared to the read noise, when using LCG mode.
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Old 07-12-2020, 09:03 PM
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Originally Posted by Camelopardalis View Post
The answer is provided by ZWO in their specs...at -10C, the thermal noise is roughly 0.0006e per second.

Simply multiple that by the number of seconds

The different between the two temperatures is negligible compared to the read noise, when using LCG mode.
Hi Dunk,

I see what you mean, I was taking 10 minute subs last night, not sure of your figure as I am looking at the ASI1600 MC Pro which says around 0.01 which is about 6 e- for 600 second subs, far less than the read noise of 2 e- if I am reading the graphs correctly.
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Old 07-12-2020, 09:06 PM
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Thanks Paul & Martin for your replies,

All I can say is I am thinking seriously about getting a ASI 2600 MC!
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Old 08-12-2020, 11:25 AM
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Everyone I have seen who has imaged with one is very happy with it (I am)

I have not yet found anyone who has a problem that can be definitively sheeted home to the camera. I have seen someone report that they cant get it to connect but that could just as easily be a cable or PC issue, or even an issue with another bit of gear, I had a problem with the USB port on my guide camera which was connected to the USB hub of my old ASI294, that turned out to be a tiny bit of corrosion from being out in the dew and was cleaned up with a bit of isopropyl, but while it was a problem it actually took my ASI294 offline as well as the guide cam (But not the focus motor, which was also on the camera hub!)

If I had the money I would buy another one and retire the ASI294, which I still have. Hopefully they make the choice harder for me and release a mono version of the 2600 next year!
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Old 08-12-2020, 11:54 AM
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Quote:
Originally Posted by Zuts View Post
Hi Dunk,

I see what you mean, I was taking 10 minute subs last night, not sure of your figure as I am looking at the ASI1600 MC Pro which says around 0.01 which is about 6 e- for 600 second subs, far less than the read noise of 2 e- if I am reading the graphs correctly.
Yeah the dark noise is a fraction of that of the 1600 even.

Makes me wonder why people _still_ think CMOS is inferior to CCD

(That's a rhetorical question, I have no interest in debating with "traditionalists")
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Old 08-12-2020, 11:55 AM
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Quote:
Originally Posted by The_bluester View Post
Everyone I have seen who has imaged with one is very happy with it (I am)

I have not yet found anyone who has a problem that can be definitively sheeted home to the camera. I have seen someone report that they cant get it to connect but that could just as easily be a cable or PC issue, or even an issue with another bit of gear, I had a problem with the USB port on my guide camera which was connected to the USB hub of my old ASI294, that turned out to be a tiny bit of corrosion from being out in the dew and was cleaned up with a bit of isopropyl, but while it was a problem it actually took my ASI294 offline as well as the guide cam (But not the focus motor, which was also on the camera hub!)

If I had the money I would buy another one and retire the ASI294, which I still have. Hopefully they make the choice harder for me and release a mono version of the 2600 next year!
Indeed!

If I had the funds, I'd be all over one of these like a bad rash
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Old 08-12-2020, 12:21 PM
Startrek (Martin)
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Thanks Paul & Martin for your replies,

All I can say is I am thinking seriously about getting a ASI 2600 MC!
You won’t be disappointed it’s a tremendous camera
Just a reminder it has an APS-C sensor size of 23.5 x 15.7 and pixel pitch of 3.76uM just to check your FOV and Sampling
The only issue I’ve had so far was initially trying to cool it down to -15C but that was my fault as I didn’t have long enough cooling steps in APT . All rectified now
Martin
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