7 replies to this topic

[JosephATL]

Last night was my first time using my new Altair 6nm Ha & Oiii filter on my 9.25 edge hd. It's an upgrade from my NBZ filter that has a 12nm bandpass so I expected I might might have to up the exposure time but I was having issues plate solving too. Usually a 4 second exposure is fine for plate solving with just the UV/IR filter, but then I upped to 11 seconds and it was still failing. The fix was an 8s second exposure with a 2x2 bin for the plate solve.

When I finally got to imaging I was stil getting plate solve errors. I have NINA plate solve after every image to check for drift but it could do it even with a 6 minute exposure. I could see on the auto stretched image that my target was in the center so I wasn't too worried.

Is this normal?

For clarification there nothing wrong with my plate solver. Ive used it many times before and set up using the 3 points polar algin that night but with the UV/IR filter.

[lumos]

What gain do you have in NINA (Options---Platesolve)? Do you have an autofocusser and is that working. What settings do you have for each filter?

[JosephATL]

What gain do you have in NINA (Options---Platesolve)? Do you have an autofocusser and is that working. What settings do you have for each filter?

I'm using the QHY 268c camera (IMX 571).  Readout mode is High Gain 2CMS, gain is 60, offset 10.  I'm using the ZWO EAF and it works...ok.  I'm not thrilled about it and want something better, but that is a for another thread. AF routines actually were fine with both the UV/IR filter and the new 6nm filter.

[lumos]

I was specifically asking about the gain you specify in NINA to do the plate solving. If that is also 60 try increasing it to 200 or even 400. 

[JosephATL]

It is by default set to the gain and offset used for imaging.  I left those settings as they were, and only changed the exposure time and then the bin when I got up to 11 sec (I don't want to spend all night on set up and calibration).

 

That's any easy thing to fix for the platesolve to target, but it doesn't explain why the platesolve fails after a 6 min exposure.

[lumos]

I use 3nm NB filters with my faster f/7 scope and only use 5 seconds at gain 200 on my ASI2600MM. The reason I suggested changing the gain was to make sure you were not getting something funky at 6 minutes such as not tracking. 

 

The very first thing I look at if a plate solve fails is what does the actual captured image look like. What does the histogram show. Looking at the image can you see lots of nice bright tight stars?

[JosephATL]

I use 3nm NB filters with my faster f/7 scope and only use 5 seconds at gain 200 on my ASI2600MM. The reason I suggested changing the gain was to make sure you were not getting something funky at 6 minutes such as not tracking.

The very first thing I look at if a plate solve fails is what does the actual captured image look like. What does the histogram show. Looking at the image can you see lots of nice bright tight stars?

I have some examples of M101 with the filter here.
https://drive.google...02cgV8J1Nb9Ttij

[lumos]

I am seeing more hot pixels than stars in the supplied images, I wonder if that is causing your problems.