×

INDI Library v1.9.8 Released (29 Sep 2022)

Bi-monthly INDI Library released with new drivers and bug fixes.

Cannot adjust exposure time with iPolar

  • Posts: 44
  • Thank you received: 5
Hi,
I’m trying to use iPolar with Astroberry and KStars 3.5.0 stable. I’m able to acquire images and videos, both at 1280x960 and 640x960, but apparently there is no way to change exposure and gain. The image has always the same appearance. Interestingly, 1280x960 has a brighter exposure than 640x960. I see no particular issue in the log, attached. I also enabled stacking in Indi panel, and played with Auto/Manual exposure settings, with no results.
Any idea?
Thanks
1 year 9 months ago #64119
Attachments:

Please Log in or Create an account to join the conversation.

  • Posts: 1941
  • Thank you received: 417
Correct, the exposure time for this camera is fixed (afaik in the hardware but I may be wrong). It cannot be changed.

Wouter
Wouter van Reeven

ASI6200MM and 7 slot 2" filter wheel with a SkyWatcher Esprit 80 ED on a SkyWatcher HEQ5-Pro
ASI1600MM-Pro Cooled and 5 slot 1.25" filter wheel with an 8" TS Ritchey-Chrétien on a SkyWatcher EQ6-R
1 year 9 months ago #64125

Please Log in or Create an account to join the conversation.

  • Posts: 44
  • Thank you received: 5
Are you sure? From this post and the followings it seems that someone was able to adjust exposure and gain.

www.indilib.org/forum/stellarmate/6710-i....html?start=12#59454
1 year 9 months ago #64128

Please Log in or Create an account to join the conversation.

  • Posts: 1941
  • Thank you received: 417
No, I am not sure but I never managed to get the exposure time higher that 0.5 seconds. That is also the exposure time used by the iPolar app on my MacBook.
Wouter van Reeven

ASI6200MM and 7 slot 2" filter wheel with a SkyWatcher Esprit 80 ED on a SkyWatcher HEQ5-Pro
ASI1600MM-Pro Cooled and 5 slot 1.25" filter wheel with an 8" TS Ritchey-Chrétien on a SkyWatcher EQ6-R
Last edit: 1 year 9 months ago by Wouter van Reeven.
1 year 9 months ago #64143

Please Log in or Create an account to join the conversation.

  • Posts: 44
  • Thank you received: 5
Yes, 0.5s seems to be an hardware limit (which is recognized by Indi v4l2 driver), however in iOptron software it is possible to change the exposure time (but apparently no more the gain with the latest release...), whereas in Indi the exposure seems fixed (decreasing below 0.5s does not have any effect, and also changing the gain). Interestingly, from an indoor test, I get roughly the same exposure of Indi by setting 31ms in iOptron software. If this is true, it may be too low for actual use (sorry, I cannot test outside, completely cloudy)
1 year 9 months ago #64162

Please Log in or Create an account to join the conversation.

  • Posts: 10
  • Thank you received: 7
Changing the exposure within the capture routine appeared to have an effect for myself and changing the gain under the V4L options certainly has an effect on the image captured. Having popped the back off the iPolar since I wrote in the thread you reference it's basically a Sonix SN9C camera controller coupled to a low light sensor, specifically an SN9C6287 which I don't seem to be able to find any data for but some code for earlier sonix drivers does reference registers that can be used for exposure control so it's reasonable to assume that it can be controlled to a point, if only coarsely, but without reading the V4L code for the drivers it's using couldn;t be sure but the maximum exposure definitely seems to be limited to 0.5.

We use the iPolar routinely (and sucessfully) with the Ekos PAA so it certainly does work. (typically a 0.25s or 0.5s exposure time with a gain of 288-384 works fine in my bortle 7 garden and much lower gain when in darker skies.)

HTH

Jacqui
Last edit: 1 year 9 months ago by Jacqui Greenland. Reason: grammatical error
1 year 9 months ago #64928

Please Log in or Create an account to join the conversation.

  • Posts: 10
  • Thank you received: 7
Thought it might be useful to add my own update here - I was/am using a very old version of kstars/ekos (3.0.0) which I can make work with the iPolar for PAA happily. Recently I have been trying to upgrade to 3.5.2 and cannot make the iPolar work with it at all (the image it takes is deemed unsolvable). I know it's Ekos as I made sure every other driver was the same on the system (indi, kernel etc) but as yet don't know at what point between 3.0.0 and 3.5.2 it stops working.
1 year 6 months ago #69683

Please Log in or Create an account to join the conversation.

Moderators: Radek Kaczorek
Time to create page: 0.361 seconds