geoflewis

Nicely done

That's lovely Graham

Those are both excellent images Stuart.

Did you mean undersampled or oversampled? I think you were saying that my Mars images were oversampled.....🤔

Thanks for the further explanation Nicolàs, so are you saying it is the large black border in the FFT of my Mars images that tells you it is oversampled? Regarding using a B-Mask for planetary focusing, for me that is a complete no. Even with aftermarket mirror locks on my C14, moving the scope from a bright star back to the planet will likely see the mirror move enough to lose focus, but in any case I don't have a B-mask for the C14..... I did have one for my old 10" Meade LX200, but that never worked well enough for me for planetary imaging, so I almost always use planetary surface features to focus.

I think I now understand......, a least a little better than I did....🤔🙄

Sorry Vlaiv, I don't understand what you did here, so please could you explain some more, thank you.

Thanks Nicolàs, I do not know what FFT is, or what it is that is clearly showing that the images are well oversampled. It is not at all clear to me what shows this, so where can I see that please? Also I think that the RESIZED 25% - 400% image has lost a bit of detail, though not a lot - maybe it just looks smoother to me. As I said to Vlaiv, the biggest issue for me is the size of the image on screen when I am trying to focus, prior to capture.

Thanks Vlaiv, I agree that they are similar, so it may just be what I said several times, which is that I prefer to work with the bigger image on screen during capture. I know that I can zoom the FireCapture window, but I find too much zoom in FC gives me a poorer quality image, so accurate focus becomes more challenging. I know that I can resize the images in post processing, but it is getting a good focus at time of capture which is critical and the bigger over sampled image helps me.

Thanks Nicolàs. Unfortunately, I do not understand a lot of what you did, nor similar analysis done by @vlaiv. All I do is try my gear and see what works for me and IMHO what I get from oversampled data is better than what I get from 'correctly' sampled data. This may just be an eyesight thing, with me prefering to work with a larger image, but I can't change my eyes, whereas I can change the image size with a barlow in the optical train. Got to run to a medical appointment now, so I'll look out for any further answers when i get back in an hour or so.

Here are 2 similar views of Mars taken several weeks apart the one dated 13 Nov 2022, was at F13 (no Barlow), the one dated 20 Dec was with the barlow in poor seeing captured through passing cloud, but I still prefer it. A much better, but slightly different view was captured with the barlow on 16 Dec. One noticible thing is that the edge rind is much more prominent in all my 'correctly' sample images. You can see them all on my Astrobin page here I pretty much changed from F13 (without the barlow) to F21 (with the barlow) wef 2 Dec. Here are 2 similar views of Mars one from 1 Dec at F13 and the second on 2 Dec at F21 with the barlow. I know which I prefer. I have also included the TIFFs if you want to poke around in imageJ or whatever you use. 2022-12-01-2345_8-GDL-RGB-Mars_lapl4_ap5_P30_sharp90_R6(Hist50-200)_Wav(10-20-30).tif 2022-12-02-0007_5-GDL-RGB-Mars_lapl4_ap26_P30_sharp90_R6(Hist50-200)_Wav(1-1-20-30-40-50).tif I have not used drizzle or resampled, resized either of those last 2 images, just run through AS3! and applied wavelets in Rexistax. If you want the raw stack TIFFs out of AS3!, here they are.... 2022-12-01-2345_8-GDL-RGB-Mars_lapl4_ap5_P30_sharp90.tif 2022-12-02-0007_5-GDL-RGB-Mars_lapl4_ap11_P30_sharp90.tif I will be genuinly interested in your findings and explanations please.

I use Firefox, but it didn't translate, so could you send me a link to the plugin that you used please?

This is difficult, as I don’t have side by side captures processed. It may just be a feeling, but the sessions I ran at ~F21 just appear better results to me than the sessions I ran at ~F12. My observing conditions in UK are very inconsistent, so maybe I was just lucky at F21, but after many sessions trying one or the other (not the same session) it seems to me that F21 is better.

Yes please, in English would be great, as I could not read your article when I opened the link.

Thanks Vlaiv, I know that you’ve said it many times, but my personal experience (and I think many others) says that oversampling gets better results. I have tried both correct sampling and over sampling and my oversampled images are almost always the better ones. I don’t understand why, maybe it easier to obtain accurate focus with larger over sampled image on screen, or something else, but operating at F21 or F24 gives me better results despite ‘correct’ sampling is ~F14. I cannot deny the maths/physics that you describe, but equally I cannot deny the evidence of my own eyes.

Nice one, well done

I think you’ll be fine with what you’ve got for starters. Give it a try and good luck.

Superb image Avani

Lovely set of images

IMHO Astronomy Tools is really only relevant for deep sky (DSO) imaging, not at all relevant for lunar and planetary imaging.

Thanks Nicolàs, yes, I am aware of the lengthy discussions about optimum FR for planetary imaging, indeed I have joined with @vlaiv and others at some length just a couple of months ago. However, many of the ‘experts’, do not follow those recommendations and I personally have better results with both colour and mono cameras when significantly over-sampled. I do not know why this is, but I used to get my best results with the 290MM at around F24, and currently F20/F21 is yielding my best results with the 462MC - both cameras have 2.9mn pixels. It is very difficult to get side by side comparisons in the UK because the conditions, especially seeing, can change significantly even after only a few minutes. It is particularly interesting that you make the distinction between mono and colour cameras and that the x7+ that I’m currently using with the 462MC is more in line with the x7.4 that you mention for RG pixels. Thanks also for the link to the article, which I will read with interest. I also look forward to your findings with the 290MM.

Yes, x5 px_size is a good rule of thumb for planetary, but I’ve recently been operating at F21 with my 2.9mn px ASI462MC and C14+Baader barlow lens, so that is more like x7.

Those are great Kostas, I couldn’t get anything usable when I went out last night, due to fog, cloud and terrible seeing.

Well I tried, but the seeing was awful and then the clouds rolled in. This is a quick look from the best of the three runs tonight (21/12), well two and a half runs as clouds crashed the last one.... It's just a blur, so I won't be bothering to take the processing any further. It is best 20k frames, I also tried best 10k and equally as bad....🙄. At least I'm back inside in the warm nice and early tonight.... 😀

Thank you very much 😊