How to Lunar Image with QHY600L

[Midnight_lightning]

I have only used my QHY600L for deep sky but would like to get some lunar shots.

I could take a standard approach and use SGP to take lots of subs and then stack but I am wondering if there is a better approach.

I have read a bit about lucky imaging using video but download times for single shots are 7 seconds full frame so not sure if it is an option - perhaps it is possible to only use part of the frame to make video run?

Any suggestions for how to approach lunar imaging with this camera?

 

[vlaiv]

I'd use following approach:

Highest F/ratio that you should use is F/15 so don't go over that if you don't have to. Faster is fine, but slower won't bring any additional detail.

Look into ROI and in particular - look at the specs for your scope. Loose any correctors you usually use for AP - these tend to correct some aberrations but sometimes soften up telescope at planetary "scales" (they trade some on axis sharpness and PSF sharpness in general for good correction over larger field). Calculate diffraction limited field for your scope and compare it to the size of the moon given your focal length.

You might be able to fit whole moon in single frame - or maybe you'll have to do mosaics to get full lunar disk. In any case - you should look into ROI that will work given your scope. Using ROI will speed up download time.

Use higher gain - one that minimizes read noise - this is important for planetary stacking.

Shoot very short exposures to freeze the seeing - like 2-3ms on the moon (5-6ms max, but moon is bright and you'll probably won't need that long exposures) - don't look at histogram - except if you start saturating / clipping in white.

 Maybe try SharpCap software - as it is somewhat specialized for planetary imaging.

Use filter - like Green filter you otherwise use for imaging. Alternatives are OIII or Ha - narrowband filters if you have those. Selecting smaller bandwidth helps with refractor optics to select part of spectrum with best correction (that is green for example) - minimizes atmospheric blur and seeing impacts less longer wavelengths (this is why Ha tends to be good as it is longer wavelength than most in spectrum).

For rest - look up some tutorials, but in essence:

- you image a ser video (or sequence of fits)

- use PIPP to calibrate those and export as a ser video again

- use AS!3 to stack that video

- In the end sharpen using wavelets in Registax and further process in app or your choice.

- If creating a mosaic - look into one of these - Microsoft ICE (no longer available for download from Microsoft site, but people kept installers and shared them online so it can be found), iMerge - small utility to merge mosaics, ImageJ has several plugins for "stitching" of images and so on ...

[Midnight_lightning]

Thanks for the detailed reply. My scope is 926mm f6.8 so with the full frame QHY600 the moon will Only fill a tiny proportion of the sensor. I will look at sharp cap.

[vlaiv]

If you want to do high resolution work - it would be good to add x2 barlow, but for starters - you can use it as you have it.

Using ROI will give you much faster download speeds.