×

INDI Library v2.0.7 is Released (01 Apr 2024)

Bi-monthly release with minor bug fixes and improvements

Re:Battling with focus

  • Posts: 10
  • Thank you received: 0

Replied by Wayne Hall on topic Re:Battling with focus

Thanks will do when the skies are clear again. Where do I find the median filter?
2 years 10 months ago #72463

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

  • Posts: 225
  • Thank you received: 16

Replied by Ron Clanton on topic Battling with focus

Are you taking dark frames for focusing? This will eliminate "fake stars" from being selected for focus. It really improved my focus accuracy.

Ron
2 years 10 months ago #72470

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

  • Posts: 10
  • Thank you received: 0

Replied by Wayne Hall on topic Battling with focus

I haven't, It seemed to not be saving files off to the dark library and kept asking to cover the scope. I'll try again, i might have done something wrong
2 years 10 months ago #72475

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

  • Posts: 10
  • Thank you received: 0

Replied by Wayne Hall on topic Battling with focus

Sorry it posted multiples times
Last edit: 2 years 10 months ago by Wayne Hall.
2 years 10 months ago #72477

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

  • Posts: 1222
  • Thank you received: 565

Replied by Hy Murveit on topic Battling with focus

I'd also say that you need to start autofocus somewhat near good focus. It doesn't do a good job of detecting stars when you're way out-of-focus. So, if the ideal will have an HFR in the range of, say HFR=1.5, then starting with an HFR of 5-10 will likely not work out. If you start at 2-3, things will work much better. 

You also need to adjust the step size for your focuser. Not sure what to say, but you don't want to use very small steps, where there are 5 inside the critical focus zone, nor very large, where a few steps and you're out of the range where stars can be detected well.
2 years 10 months ago #72480

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

  • Posts: 225
  • Thank you received: 16

Replied by Ron Clanton on topic Battling with focus

Have you tried the "Dark Library" feature in the Capture tab? It makes it really easy to take all of your dark frames in a range of exposures and bins.

Ron
2 years 10 months ago #72490

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

  • Posts: 10
  • Thank you received: 0

Replied by Wayne Hall on topic Battling with focus

Thanks, I typically start close to perfect focus. Typically get 1.8 HFR and I start 2-2.5 sort of range. I had a step size of 50 which throws it WAY out, I'll try making that smaller as well.
2 years 10 months ago #72515

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

  • Posts: 10
  • Thank you received: 0

Replied by Wayne Hall on topic Battling with focus

I'll try this again later tonight. Didn't have luck capturing darks when I did it before but will try again
2 years 10 months ago #72516

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

  • Posts: 319
  • Thank you received: 25

Replied by Mohamed on topic Battling with focus

My 2 cents as I faced such problem before (for a whole night), use 2x2 binning, start close to good focus with L filter, make sure your mechanics is suitable for your focuser (in my case max step was 1000, and each step is 100), set the exposure time for Ha, O3 and S2 filters to 15 seconds and most importantly in my case was enabling the coil power, as I discovered later that the optical train was heavy and always change position by gravity.

Since I made the above changes, my focuser works fine since then

hope this helps
The following user(s) said Thank You: Eric
2 years 10 months ago #72519

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

  • Posts: 10
  • Thank you received: 0

Replied by Wayne Hall on topic Battling with focus

Thanks for the help guys. Its been working reliably so far. I found that adding the median filter, 5s exposures for the narrowband filters, and changing the step size down and max steps out have helped a ton. WIll keep trying it out to see if its really 100% reliable. 
2 years 10 months ago #72528

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

  • Posts: 1029
  • Thank you received: 301

Replied by Eric on topic Re:Battling with focus

That's great. Also consider focusing with the fastest filter you have, and using filter offsets.

-Eric
2 years 10 months ago #72529

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

  • Posts: 10
  • Thank you received: 0

Replied by Wayne Hall on topic Re:Battling with focus

I will try that, my focuser does have some nasty backlash so I was concerned the offsets wouldn't be reliable.
2 years 10 months ago #72532

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

Time to create page: 0.806 seconds