Banging head on wall

[badgerchap]

Hi all,

I don't really like posting "what am I doing wrong" type posts, but I'm getting pretty frustrated with planetary AP so rather than pull any more hair out, I'm succumbing to the siren-call of SGL and i ts ever knowledgeable denizens.

Enclosed are my two best planetary images to date, both taken as 200 frames through a Celestron C8 & Celestron Ultima 2x Barlow with a monochrome uEye ui-1480le-m-hq (link: https://en.ids-imaging.com/store/ui-1480le-rev-2.html). The camera's not ideal due to its low frame rate, but I don't think it's the limiting factor here.

Data processed in PIPP and Autostakkert!3, roughly following JamesF's excellent guide: https://stargazerslounge.com/topic/184821-beginners-guide-to-stacking-planetary-images-with-autostakkert2/

I'm getting frustrated as I keep seeing other people's 'first planetary images' and they're routinely far superior to mine despite using more modest equipment and by people with far less astronomical experience than myself who, with the exception of planetary imaging, has been at this game for about 12 years now.

It's not all bad; I can just about make out the hint of some detail where the Cassini division should be, and Jupiter isn't quite a mere grey disc, but still, I somewhat hoped for more. I suspect that focus is at least part of my issue, so as well as the general "what am I doing wrong", there's also a question about how people tend to focus for planetary imaging.

Thanks in advance for any tips or tricks anyone can give!

[carastro]

To be honest I gave up planetary imaging after trying for several years and making little progress, I find it far more difficult than DS imaging.

I certainly think part of your issue is focus and again focus was difficult for me as well.  I was told to focus on the Moon and then lock the focus and it will be the same focus for the planets, and this helped when the Moon was up.   I was also told to use a Bahtinov Mask on Jupiters Moons and that also helped though they are quite small and sometimes difficult to get them to show up.  I seem to recall having to change the settings in your capture software to reveal the Moons.

HTH

Carole 

 

Edited June 15, 2020 by carastro

[badgerchap]

Certainly seems like a dark art! 

I can certainly reveal the moons by over exposing, so I'll try using them to focus, although I don't have a Bhatinov or a printer to help me make one. Still, they might be easier to focus than the disc of Jupiter.

[carastro]

You can make your own, and they are not expensive to buy anyway.  Or you can make a Y mask dead easy.  You can make them from cardboard (need smooth cuts though) , plastic board, I once made a Y shape cut it out and laminated it and just stuck it onto a collar to keep it on the scope.  

https://www.google.com/search?q=Y+mask+for+focus&client=avast&sxsrf=ALeKk02oQZT2mzG8UnLVApBPtSvMwHiBGw:1592225720532&tbm=isch&source=iu&ictx=1&fir=VS_TVosDokquMM%3A%2CGEIg7nQzpT7ooM%2C_&vet=1&usg=AI4_-kRhNfdzqDC9x_FlfvmqjEfsIXYz8w&sa=X&ved=2ahUKEwjLyeWD74PqAhXTQ0EAHeX3BLoQ9QEwAHoECAoQAw&biw=1004&bih=615#imgrc=VS_TVosDokquMM:

https://www.cloudynights.com/topic/224593-better-alternative-to-bahtinov-focusing-mask/

Carole 

Edited June 15, 2020 by carastro

[badgerchap]

4 minutes ago, carastro said:

Or you can make a Y mask dead easy.

Oh thanks, not heard of that approach before! Stupid question: is the 'Y' hole or mask? I ask because if it's hole the middle would need supporting?

[carastro]

The Y is solid, the space is around it, so if you make a Y the tips will need to be attached to something.   A couple of pictures I found on the Net. 

 

Edited June 15, 2020 by carastro

[badgerchap]

Ah good, thought so. Would be a bit of a faff otherwise! 

 

Excellent, thanks Carole, I'll give that a try next time the sky elves deign to let me see past the clouds again!

[carastro]

[RayD]

I totally agree with Carole in that the focus looks a little soft.  Also 200 frames seem a pretty small number if you are looking to pull out a fair bit of detail.  By way of example, I would usually use a minimum of 1,000 (usually 2,000) and stack the best 30% of that lot.

[symmetal]

I focus on a nearby star with a bahtinov mask. You may have to up the camera gain and exposure a lot to get 'useable 'spikes'.

For the planet itself you want as low an exposure duration as you can manage to try and 'freeze' the seeing. 5mS is a good starting exposure. You may then have to put a lot of gain in the camera to get a bright enough image and it looks like a mass of noise on the preview, but once the frames are stacked the noise is 'magically' reduced a great deal. Take several videos at different exposures and gains and see which gives the best stacked image.

A high frame rate just means you can get your 1000 frames or more quicker. It doesn't by itself make the image better. It just means there's less a chance of clouds etc. upsetting the video. With Jupiter however, too long a video, over several minutes, will lead to image blurring due to planet rotation.

Alan

[badgerchap]

12 minutes ago, symmetal said:

 

A high frame rate just means you can get your 1000 frames or more quicker. It doesn't by itself make the image better. It just means there's less a chance of clouds etc. upsetting the video. With Jupiter however, too long a video, over several minutes, will lead to image blurring due to planet rotation.

Alan

Hi Alan, thanks for that, plenty of stuff for me to work with in there. I suspected as much with the camera.

I do have a DSLR though which I use for DSO imaging. I was considering using that instead as it's colour, but it also has a slightly larger pixel size (5.2 um vs. 2.2 um). Would you expect this to cause a serious decrease in resulting image quality for an otherwise identical setup? I don't really have much of a feel for this yet!

 

Thanks

[maw lod qan]

Never surrender, never give up!

When everything falls into place you find yourself smiling and saying "oh yeah!"

[badgerchap]

Just now, maw lod qan said:

Never surrender, never give up!

When everything falls into place you find yourself smiling and saying "oh yeah!"

Yep, I remember getting that when I got my first Horsehead

[symmetal]

23 minutes ago, badgerchap said:

Hi Alan, thanks for that, plenty of stuff for me to work with in there. I suspected as much with the camera.

I do have a DSLR though which I use for DSO imaging. I was considering using that instead as it's colour, but it also has a slightly larger pixel size (5.2 um vs. 2.2 um). Would you expect this to cause a serious decrease in resulting image quality for an otherwise identical setup? I don't really have much of a feel for this yet!

Your uEye camera doesn't look like it has a ROI (Region of Interest) selection which would normally enable higher framerates.

It's worth trying your DSLR. It's larger pixels means the on screen image will be less than half the size for a single frame, but should therefore give a brighter image as more planet area is covering a pixel Unfortunately, many DSLRs downscale the full frame image to video resolutions leading to a lower quality smaller video image.

The drawback with DSLR videos is that they are lossy compressed, mp4 or similar, so stacking can't do such a good job  as using uncompressed videos but should still give a reasonable image. If your DSLR can do centre cut-out videos where the central 1920 x 1080 pixels (or whatever the video resolution is) are used for the video instead of downscaling the full frame, you'll get a larger, higher quality image. Canon camera users can install the 'Magic Lantern' firmware which enables centre cut-out video recording.

Alan

Edited June 15, 2020 by symmetal

[badgerchap]

6 minutes ago, symmetal said:

 

The drawback with DSLR videos is that they are lossy compressed, mp4 or similar, so stacking can't do such a good job  as using uncompressed videos but should still give a reasonable image. If your DSLR can do centre cut-out videos where the central 1920 x 1080 pixels (or whatever the video resolution is) are used for the video instead of downscaling the full frame, you'll get a larger image. Canon camera users can install the 'Magic Lantern' firmware which enables centre cut-out videos.

Alan

I was recently reading that you should take a series of stills rather than a video with a DSLR, but this seems unlikely to be successful with Jupiter as getting enough images without showing rotation whilst also avoiding shutter vibrations seems unlikely, Does that seem correct?

[symmetal]

2 minutes ago, badgerchap said:

I was recently reading that you should take a series of stills rather than a video with a DSLR, but this seems unlikely to be successful with Jupiter as getting enough images without showing rotation whilst also avoiding shutter vibrations seems unlikely, Does that seem correct?

For lunar images stacking a series of DSLR stills would be likely to give a better image more easily than video recording. It's certainly worth trying for planets. It'll give you an idea of what can be achieved. Jupiter's rotation really only starts to be noticeable on high resolution images after a few minutes. For your size images it won't really cause any issues. If your image is good enough that only the planets rotation is causing it to look a bit blurry I think you'd be very happy. 😁

Alan

[badgerchap]

5 hours ago, symmetal said:

If your image is good enough that only the planets rotation is causing it to look a bit blurry I think you'd be very happy. 😁

 

Now that is a remarkably good point! 🤣

[carastro]

Quote

I focus on a nearby star with a bahtinov mask.

Depends on the camera, not all web cameras used for planetary are capable of seeing stars.

Carole  

[knobby]

If your pixels are 2.2 then you're probably better off ditching the Barlow, ideally you want the f no. to be about 5 X pixel so f 11. You're at f 22. Also you look a bit over exposed so try a faster frame rate. Good luck and stick at it.

[Cosmic Geoff]

It looks like focus is your major issue.  The suggestions above are good.  I generally focus either on Jupiter's moons or on a star.  I have also seen the suggestion from an experienced imager that one focus on the planetary detail.  Good single frame captures should look better than the images above.

I think that your choice of camera is another issue.  If you use a dedicated planetary camera (at a minimum ZWO ASI120MC-S or similar, or better a ASI224MC with IR-cut filter, or equivalent) you can get frame rates exceeding 200fps on Jupiter and can easily save videos of 5000 frames or more. These cameras allow you to adjust the region of interest, closing in on the planet and increasing the possible frame rate.

Once you achieve better images, you will start to see the need for an atmospheric dispersion corrector (ADC) also available from ZWO.

 

[Pete Presland]

Not at all familiar with the camera you are using. 6FPS is painfully slow though, you should still be looking to capture more than 200 frames, as you do at least 180 second imaging runs (1000+) frames. the imaging scale for Jupiter looks too big to me, which would focusing even harder as well. Saturn looks a bit overexposed.

As for focusing i follow the same process every time. Firstly i don't stand to close to the monitor, i then experiment inwards and outwards slowly making smaller movements in each direction, until i think i am somewhere close to the point of focus. I then watch the image for a period of time to see what it looks like at the better moments, as the focus tends to come and go depending on the seeing conditions on the night.

[nfotis]

On 15/06/2020 at 16:48, symmetal said:

Your uEye camera doesn't look like it has a ROI (Region of Interest) selection which would normally enable higher framerates.

It's worth trying your DSLR. It's larger pixels means the on screen image will be less than half the size for a single frame, but should therefore give a brighter image as more planet area is covering a pixel Unfortunately, many DSLRs downscale the full frame image to video resolutions leading to a lower quality smaller video image.

The drawback with DSLR videos is that they are lossy compressed, mp4 or similar, so stacking can't do such a good job  as using uncompressed videos but should still give a reasonable image. If your DSLR can do centre cut-out videos where the central 1920 x 1080 pixels (or whatever the video resolution is) are used for the video instead of downscaling the full frame, you'll get a larger, higher quality image. Canon camera users can install the 'Magic Lantern' firmware which enables centre cut-out video recording.

Alan

 

At least on Canon dSLR, you can use the ALL-I option, which means essentially uncompressed HD video - that should offer quite an improvement compared to the typical setup.

 

N.F.

 

[si@nite]

Its not easy planetary imaging at the best of times, using a dslr makes life even more difficult because lots of frames are needed to give a good stack result!

On ‎15‎/‎06‎/‎2020 at 20:53, knobby said:

If your pixels are 2.2 then you're probably better off ditching the Barlow, ideally you want the f no. to be about 5 X pixel so f 11. You're at f 22. Also you look a bit over exposed so try a faster frame rate. Good luck and stick at it.

I agree your images are over exposed & looks like there are focus issues too!

Ive reprocessed your Saturn image taking these issues in to account pulling more detail out you can clearly see the cassini & some banding on the globe!

[zcapp96]

I had a very similar result when using my new c9.25 the other week. I found it was the barlow, it was not in the correct position in the imaging train so was giving much more than 2x and with the low altitude just too much to achieve focus. Try without the barlow and see if that image gets more detail.

[badgerchap]

On 03/07/2020 at 09:10, si@nite said:

Its not easy planetary imaging at the best of times, using a dslr makes life even more difficult because lots of frames are needed to give a good stack result!

I agree your images are over exposed & looks like there are focus issues too!

Ive reprocessed your Saturn image taking these issues in to account pulling more detail out you can clearly see the cassini & some banding on the globe!

Only just spotted this. Thanks! That's a great improvement!!

Considering you had only one frame to work with too! What did you do?