Planets: Still v video

[Jezphil]

Hi. A muddling-though newbie's question from me here...

Question 1: I'm planning to stack some pictures of Jupiter, using Lynkeos. I'm using a Skywatcher Evostar 120ED, HEQ5 equatorial mount and Canon EOS Ra. What will give the best results? 1) Stacking still frame photos, or 2) Stacking video? All advice welcome! 

Question 2: I plan to use an Astronomik 742 ProPlanet clip filter for the above. I tested this on the moon (not with my telescope, but with EOS Ra camera and 600mm Sigma zoom lens) but it made the moon image so dark in the camera that I could barely see it and couldn't see well enough even to focus it, even after changing the ISO and film speed to make it brighter. It makes the image incredibly dark. Presumably it'll be even darker when I use it with the telescope on Jupiter. 

Jeremy

[RT65CB-SWL]

Hi @Jezphil and welcome to SGL. 

ref: question 1. As long as your camera can 'shoot' an .AVI -> process in PIPP -> then process in Registax or Deep Sky Stacker.
If it is a .MOV then that will need to converted to .AVI 

Unsure about question 2. Hopefully a more experienced astro-imager/SGL'er will be able to assist and answer.

BTW - I am purely visual at time of writing.

[happy-kat]

With planetary imaging you ideally want to use video to be to get an image made from the best data as atmosphere turbulence will show more on still images as you don't take as many.

Deep sky stacker DSS is aimed at deep sky objects and not the Moon or planets really

Without a filter I would anticipate an exposure around 1/200 and iso say 200 for stills on the Moon though video gives more data to play with to get a nice image.

[Cosmic Geoff]

  Ideally you want a dedicated  planetary video camera. It seems you refer to an infrared filter.  My ZWO camera, having some IR response, can be fitted with an IR-cut filter for normal use or an IR-pass filter for imaging in infrared.   Video exposure times are about 10x longer in infrared.

If your camera is unmodified (red filter not removed) ir may have no IR response at all.

[Jezphil]

Thank you all for your super-fast replies! Very useful and much appreciated. Just to address some of the points...

I'm using Lynkeos to stack, so no need to convert to .avi.

My camera is a Canon EOS Ra, so it's a dedicated astronomy camera, but not specifically a dedicated planetary camera. 

Bright Giant: many thanks - understood and will go for video rather than stills.  I've been using around 1/200 and ISO for Moon stills and am confident with the moon. Hoping to be more adventurous now and try Jupiter video stacking so thanks for your advice. Would I use one burst of video and use those frames? Ten seconds of video? Or multiple segments?

 

 

Edited July 16, 2020 by Jezphil

[happy-kat]

Are you a static or tracking mount

I think aim for no more than a minute or two video clip even if tracking mount as the planet will be rotating

Edited July 16, 2020 by happy-kat

[Jezphil]

Bright Giant - I am on a Sky Watcher HEQ5 Pro, so tracking and can do longer clips. And will try a minute or two - thanks. 

Edited July 16, 2020 by Jezphil

[happy-kat]

Does your camera support video crop mode ) some canons do) as it'll focus the video in the middle where hopefully the planet is

[Aramcheck]

5 minutes ago, Jezphil said:

...tracking and can do longer clips.

I read the other day that rather than recording say a 10min video, it's better to do 5x2min or 10x1min video's & then to use the free WinJupos software to help de-rotate the images:-
https://www.skyatnightmagazine.com/astrophotography/astrophoto-tips/use-winjupos-derotate-planetary-images/

Cheers
Ivor

[Jezphil]

Yes, it has a function called 'cropping' in the video menu. But the flip-out screen on the Canon Ra magnifies x30 in the viewfinder which really helps manual focusing and makes it easy. Wouldn't I be better off focusing manually with the excellent focusing dials on the telescope (bigger dial and smaller dial for fine tuning) and looking at the x30 image? 

[Jezphil]

Star Forming - thanks. I'm trying to avoid converting to .avi files and I think both those software options need .avi. Was thinking Lynkeos was therefore the route to take. I am trying to keep the post-processing as simple as possible, at least for now, as I am a newbie. Lynkeos looks fairly easy to use and requires no conversion from Canon files on a Mac. 

[miguel87]

15 minutes ago, Jezphil said:

Yes, it has a function called 'cropping' in the video menu. But the flip-out screen on the Canon Ra magnifies x30 in the viewfinder which really helps manual focusing and makes it easy. Wouldn't I be better off focusing manually with the excellent focusing dials on the telescope (bigger dial and smaller dial for fine tuning) and looking at the x30 image? 

Cropping will give you a 1:1 pixel ratio for your image and is the optimal way to pick up planetary detail. Use this video mode if you can for all planetary photography.

[Jezphil]

Proto star - okay, thanks. Will figure out how this works. 

[happy-kat]

Just to say like your name is Jezphil mine is happy-kat, bright giant refers to post count 🙂

[Jezphil]

Ah - apologies, happy-cat! Doh! Was just thinking re cropping... The Canon Ra camera does record video in 4k. Would this be a good way to go? i.e. more pixels for cropping. But maybe 4k doesn't the work with Lynkeos and I need to do a test.

[happy-kat]

The word cropping is a misnomer, see Miguel87 post above

Experimentation is fun

Edited July 16, 2020 by happy-kat

[Jezphil]

Indeed Happy-kat. Just experimented and discovered Lynkeos is happy to process 4k mp4 movie files, so will record in that format. 

[miguel87]

1 hour ago, Jezphil said:

Indeed Happy-kat. Just experimented and discovered Lynkeos is happy to process 4k mp4 movie files, so will record in that format. 

I know it seems weird, but you might better more detail in cropped video than in 4k.

I'm no expert but basically you have more sensors on your camera chip than pixels in a 4k image, I think! So a tiny detail from the chip might get lost in translation to 4k. Whereas crop video pulls out one pixel per 'sensor' on the chip. That's why it only uses part of the sensor and the picture appears more magnified.

I guess it depends on the individual camera but it is something worth looking at.

[Jezphil]

Thanks miguel87. Will investigate. 

[Jezphil]

Thanks Miguel87. Got it now. The camera is now set with cropping enabled. It allows this to combine with 4k. So would you use cropped 4k or cropped 1080p? Presumably cropped 4k?  This works with Lynkeos.

Edited July 16, 2020 by Jezphil

[miguel87]

11 minutes ago, Jezphil said:

Thanks Miguel87. Got it now. The camera is now set with cropping enabled. It allows this to combine with 4k. So would you use cropped 4k or cropped 1080p? Presumably cropped 4k? 

Not sure about that one. I would guess the same as you. Mighy dictate the area of the sensor used perhaps? I'd go with 4k 🤷‍♂️

[Jezphil]

Thanks for your time. Much appreciated.

[happy-kat]

try both or you wont know which is better for your end result, the image if the planet.

[Owmuchonomy]

Using a DSLR in video crop mode is best for planets. The planet will only cover a small part of your sensor so capturing anything else is just data you don’t want to be trying to process. If it has 640 x 480 crop mode then use that at the fastest speed it can attain. Also, I imagine your pixels are around the 5 micron size so you need to get your scope to about f/20. A 2.5 Barlow would work well. Good luck.

[Jezphil]

Thank you all.