9 replies to this topic

[SkyRx83]

If you plan to shoot an emission nebula with an OSC and a narrowband filter is the recommendation to polar align without the filter in place and then add it once aligned and you go to your target?  I'd like to shoot the Lagoon Nebula and this is my equipment for this session:

RedCat 61
AM5N
ASIAir2600 MC Pro
ASIAir Plus
ASI 120mm Guide cam
ZWO 30mm F/4 MiniScope

Optolong L-Quad Enhance filter

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[rlmxracer]

All you need to do is set the centering time to 5 seconds in the mount section of the app. The standard 2 second exposure is too short unless you are under dark skies. 
Welcome to CN.

Edited by rlmxracer, 24 June 2025 - 06:53 PM.

[SkyRx83]

I just updated my ASIAir Plus and it now limits PA exposure times to only 3 seconds.  I found I could not PA at all with the Optolong L-Quad Enhance filter in place.  I spent two hours trying.until I finally figured out it was likely the filter.  Thanks for the welcome to CN! 

[rlmxracer]

How many stars did the plate solving screen say it detected?

[DirtyRod]

Yes. I PA with just an IR-Cut or even no filter and then swap in the filter before kicking off the plan.

 

The L-Quad is not very restrictive so 3s will probably work with that filter anyway. 

Edited by DirtyRod, 24 June 2025 - 08:11 PM.

[Alex McConahay]

If you can get a good plate solve with a reasonable exposure using the filter, go ahead and do so. Just keep it on through the Polar Alignment procedure. 

 

However, these filters are known to cut down on the amount of light available to the sensor, thus, you need to increase the exposure. If you can, fine. No problem. But if the exposures are taking too long, or you are not getting good plate solves, it will be frustrating. 

 

So, take the filter off, and use the routine to polar align. And replace the filter. 

 

THe plate solver and the polar alignment routine based on it does not care whether there is a filter in front of the sensor or not. YOu get the same polar alignment either way. It does, however, care if it is getting enough light. And that is something that is easy to experiment with. 

Alex

[rlmxracer]

Yes. I PA with just an IR-Cut or even no filter and then swap in the filter before kicking off the plan.

 

The L-Quad is not very restrictive so 3s will probably work with that filter anyway. 

I misspoke earlier and didn’t realize the PA screen no longer allows 5 second exposures. Pretty dumb on ZWO’s part because not everyone has a wheel or drawer set up to easily swap filters. 

[AnneD]

I updated my ASI Air Plus yesterday and tonight I was able to PA with the Optolong Ultimate filter in the filter drawer. I do not recall the exposure time it used and will pay attention to that the next time. It did take me longer to PA tonight, but I figured that might be due to the heat and humidity in the air tonight.

[DirtyRod]

I misspoke earlier and didn’t realize the PA screen no longer allows 5 second exposures. Pretty dumb on ZWO’s part because not everyone has a wheel or drawer set up to easily swap filters. 

I assume that’s another bug. I’d bump the exposure or go Bin2 until they fix it or just pull the filter.

Edited by DirtyRod, 24 June 2025 - 10:48 PM.

[DirtyRod]

Looks like ZWO is re-releasing 2.3.3 for both IOS and Android until they sort out 2.4x.

 

Links pinned in the FB forum page.