ASI1600 giving totally white frames

[gorann]

A few days ago I attached my ASI1600MMpro (had it for 10 months now) to my Meade 14" LX200R (with Lepus 0.62x reducer so f/6.2) and successfully grabbed some 15 min subs using my usual settings: gain 139, offset 50, raw16, 1x1 bin, -20°C. Last night I tried collecting more subs using the same settings and the 15 min subs turned out all white = completely overexposed (attached here). I changed computer from a Dell Windows 10 laptop to a Mac laptop, bot running the ASICAP program, but still just white frames. I then tried a 90 s exposure and could see my target (NGC 7331) but the image was extremely grainy also attached here). I gave up and changed to my ASI071 and it worked like expected.

I have now registered at the ZWO support site and will ask the question there when their administrator accepts me as new user, but meanwhile I take the chance to ask you at SGL if you have any idea what is going on. My ASICAP is version 1.6.1. I recently updated to this latest version so maybe there could be a bug there that locks the camera at the highest gain even it it shows gain 139 (I use a higher gain for framing and focusing and turn it down when I start imaging).

2019-08-29-2131_7-CapObj_0001.FIT 2019-08-29-2131_7-CapObj_0001.FIT.txt 2019-08-29-2131_7-CapObj_0002.FIT 2019-08-29-2131_7-CapObj_0002.FIT.txt

[Adam J]

1 hour ago, gorann said:

A few days ago I attached my ASI1600MMpro (had it for 10 months now) to my Meade 14" LX200R (with Lepus 0.62x reducer so f/6.2) and successfully grabbed some 15 min subs using my usual settings: gain 139, offset 50, raw16, 1x1 bin, -20°C. Last night I tried collecting more subs using the same settings and the 15 min subs turned out all white = completely overexposed (attached here). I changed computer from a Dell Windows 10 laptop to a Mac laptop, bot running the ASICAP program, but still just white frames. I then tried a 90 s exposure and could see my target (NGC 7331) but the image was extremely grainy also attached here). I gave up and changed to my ASI071 and it worked like expected.

I have now registered at the ZWO support site and will ask the question there when their administrator accepts me as new user, but meanwhile I take the chance to ask you at SGL if you have any idea what is going on. My ASICAP is version 1.6.1. I recently updated to this latest version so maybe there could be a bug there that locks the camera at the highest gain even it it shows gain 139 (I use a higher gain for framing and focusing and turn it down when I start imaging).

2019-08-29-2131_7-CapObj_0001.FIT 31.26 MB · 3 downloads 2019-08-29-2131_7-CapObj_0001.FIT.txt 400 B · 1 download 2019-08-29-2131_7-CapObj_0002.FIT 31.26 MB · 1 download 2019-08-29-2131_7-CapObj_0002.FIT.txt 399 B · 1 download

Check out your offset setting too. 

I would say that 15min subs on a ASI1600mm pro are very long.... even in narrow band I only shoot 5mins at unity. 

Another possibility is that you had some high level cloud and it is just over exposed just to higher sky brightness. The fact that at lower exposure you see something but at poor S/N might support that theory. 

Shoot some Dark frames at the same settings, if they look normal for that length of exposure then I really doubt its the camera, if they white out then its the camera or firmware or settings. 

Adam  

[gorann]

50 minutes ago, Adam J said:

Check out your offset setting too. 

I would say that 15min subs on a ASI1600mm pro are very long.... even in narrow band I only shoot 5mins at unity. 

Another possibility is that you had some high level cloud and it is just over exposed just to higher sky brightness. The fact that at lower exposure you see something but at poor S/N might support that theory. 

Shoot some Dark frames at the same settings, if they look normal for that length of exposure then I really doubt its the camera, if they white out then its the camera or firmware or settings. 

Adam  

The 15 min subs worked well the night before (I usullay also do shorter subs but Vlaiv talked me into 15 min and it worked for this rather faint object). Sky konditions was good with an SQM of 21.3 and fair guiding (0.6 "/pix) so I doubt it was the sky (the SQM would have picked that up). My FITS headings confirms all my settings inkluding gain 139 and offset 50. I will see if I can fins an older version of ASICAP.

[david_taurus83]

I also shoot 15 minute subs in narrowband. Get very good results. As Adam has said, shoot some darks and see if they are ok. I use the same settings as you, unity gain, -20 etc. A 900s dark at 50 os should have a median value of around 850 adu. 60 os should be around 950 adu, there or there abouts.

[gorann]

3 hours ago, david_taurus83 said:

I also shoot 15 minute subs in narrowband. Get very good results. As Adam has said, shoot some darks and see if they are ok. I use the same settings as you, unity gain, -20 etc. A 900s dark at 50 os should have a median value of around 850 adu. 60 os should be around 950 adu, there or there abouts.

Thanks for the suggestions. I tested darks yesterday and the were dark. My theory is that there was some bug that made the gain remain very high even it it was set on 139. I may get dark skies tomorrow so I could test it for real again. I will also see if I can dig up an older version of ASICAP if this somehow was caused by a bug in the new version (1.6.1)

[Adam J]

On 31/08/2019 at 13:45, gorann said:

Thanks for the suggestions. I tested darks yesterday and the were dark. My theory is that there was some bug that made the gain remain very high even it it was set on 139. I may get dark skies tomorrow so I could test it for real again. I will also see if I can dig up an older version of ASICAP if this somehow was caused by a bug in the new version (1.6.1)

The classic one is that if you have a ZWO guide camera (which i see you do) PHD2 can get confused and end up setting the gain of the ASI1600mm pro to the gain intended for the guide camera.

[gorann]

22 minutes ago, Adam J said:

The classic one is that if you have a ZWO guide camera (which i see you do) PHD2 can get confused and end up setting the gain of the ASI1600mm pro to the gain intended for the guide camera.

Thanks and Yes, but unfortunately not in this case since I used my Lodestar X2 and I also run the guiding on a separate laptop just to avoid confusions like that (which I have had in the past). I have now installed the previous version of ASICAP and got the rig up - only waiting for clouds to clear around midnight, but so far the ASI1600 appears to respond properly to my gain settings.

[Guest]

The best would be, to report a case + a file where the subs turned out all white to the ZWO ASI Support group, so they analyze the reason, my ZWO ASI 1600 ( V2 and not the PRO version ) does the same.. " sometimes "  

https://bbs.astronomy-imaging-camera.com/

Edited September 2, 2019 by Guest

[gorann]

1 hour ago, artem said:

The best would be, to report a case + a file where the subs turned out all white to the ZWO ASI Support group, so they analyze the reason, my ZWO ASI 1600 ( V2 and not the PRO version ) does the same.. " sommetimes "  

https://bbs.astronomy-imaging-camera.com/

I am still waiting to get administrator approval by the ZWO support site so I can send them some subs. In any case, it worked most of last night but then did it again after the flip. I restarted ASICAP and then it worked again, so I seem to be in the same "sometimes" situation as you.

[Guest]

Did you contact ASI? and have any feedback from them ?

 

[retret66]

are you using another zwo camera as guide camera? usually I believe I experience this when there is a conflict between two camera. I don't let the computer choose, I choose the camera manually via ascom. are you experiencing this with just one camera attached?

Edited September 15, 2019 by retret66
addition

[gorann]

6 hours ago, retret66 said:

are you using another zwo camera as guide camera? usually I believe I experience this when there is a conflict between two camera. I don't let the computer choose, I choose the camera manually via ascom. are you experiencing this with just one camera attached?

 

On 14/09/2019 at 20:11, artem said:

Did you contact ASI? and have any feedback from them ?

 

No at the time I was using a Lodestar X2 for guiding and no I have not contacted ZWO.  It is generally working now. Once or twize I have had to restart it when its seems like it does not respond to the gain command and stays on the high gain I use for focusing and framing. If the problem comes back (I am shooting right now and it works) I will contact ZWO.

[retret66]

I don't think this is an issue with the camera, I am sure because this happens to me before when I let the capture app select the driver. I can duplicate this anytime. I use APT and if I just choose ASI1600mm from the list this will happen. I have 3 ASI1600mm connected at the same time.

[gorann]

2 hours ago, retret66 said:

I don't think this is an issue with the camera, I am sure because this happens to me before when I let the capture app select the driver. I can duplicate this anytime. I use APT and if I just choose ASI1600mm from the list this will happen. I have 3 ASI1600mm connected at the same time.

Yes it is most likely a software issue. As long as I am aware of it and remember to check I can live with it.