How many frames for lunar disc?

[nft_photo_art]

Hi to everyone! Will make my first lunar imaging session in some days, I never done an imaging session by myself.
I know general rules for deep sky as I use remote imaging for that, but for lunar/solar disc I don't know basically anything except that you have to record a video and the basical workflow needed.
So when you capture the entire lunar disc how many frames do you use minimum? There is a maximum? If you know some nice tutorial which explain general rules I would be very happy to read it.

My "setup" is:
Telescope: Bresser Pollux 150/750
Sensor: Svbony SV105
No tracking (the main reason for this questions)

Thank you so much for your time

[vlaiv]

People often use couple of thousand of subs.

It is more important to keep individual subs short - less than 5ms to freeze the seeing.

You will have trouble capturing full lunar disk with that camera - camera sensor is very small and at 750mm focal length - it won't cover whole lunar disk. FOV will look something like this:

You will need at least 6 to 8 panels to do whole disk.

Another issue with that camera is that it is USB 2.0 camera that uses compression. That introduces artifacts in the image and if you follow usual tutorial for planetary lucky imaging  (capture video, stack, wavelet sharpen) - it is likely that you will have issues with compression artifacts.

Having said all of that - you need at least one hundred of stacked subs and often people only use few percent of total capture. Good thing is that you are not time limited when shooting the moon (unlike other planets) - and you can shoot say 5000 subs even at 30fps (that will take 5000/30 = 166.7s or about 3 minutes) and keep 2% best subs - that will give you 100 subs to stack (maybe you will get to keep even 5-10% of best subs - depending on seeing during the session).

[nft_photo_art]

Thank you so much for precious advices, I'm currently making some experiments with the camera in daytime to better understand all the technical features of it. The compression of the camera is what gives me more thought, but using only 5 or 10% of best frames in PIPP+AutoStakkert I would be able to discard frames which introduces artifacts, right?

 

[vlaiv]

38 minutes ago, nft_photo_art said:

The compression of the camera is what gives me more thought, but using only 5 or 10% of best frames in PIPP+AutoStakkert I would be able to discard frames which introduces artifacts, right?

I'm afraid not.

Artifacts are there in every frame. They are usually not seen in single sub, after all - that is the reason they are used at all - because they don't mess up image in normal usage.

Problem with lucky imaging and those artifacts is that we sharpen our result to bring out detail. We can do that because we stack many subs and have high SNR. If you sharpen just one image - you will bring out the noise - but by stacking many images you average noise out because it is random - and it is no longer issue for sharpening.

Same process happens for artifacts - only difference being - artifacts are not random and they don't really average out. They remain in the image after stacking.

[nft_photo_art]

It's really clear, thank you a lot! I will try a session