Images taken with a DLSR

[AstroGee]

....Well mirrorless actually but I use the term to differentiate from a dedicated astro setup.

I wanted to share some images taken with a Canon EOS R and super telephoto lens so people can get an idea of what can be achieved. These are first attempt shots so could no doubt be improved with experience and environmental conditions. They are also taken from inner London, so limited to the moon and large planets.

Here is the moon, taken last week, with the Canon EOS R, 800mm RF lens and a 2x teleconverter. The camera was on a decent tripod and stabilisation enabled. I was pleasantly surprised by the detail at such a high f-stop of f/22.

I hope to add more as they are finished. Thanks for looking.

[rickwayne]

Nice! Single frame, right?

 

[AstroGee]

12 minutes ago, rickwayne said:

Nice! Single frame, right?

 

Yes, just a single frame. I will work out alignment and stacking in due course I'm sure.

Edited October 22, 2021 by AstroGee

[AstroGee]

Here is an image of Jupiter and moons, again from inner London. RF 800mm + 2x teleconverter, heavy crop. Just a single shot, exposed for the highlights.

Edited October 23, 2021 by AstroGee

[AstroGee]

One more, Saturn with similar settings to before.

These were moving very fast across the sensor, I had to recompose every 30s or so.

Thanks for looking, hope they were useful to some others who only have a DLSR. Star tracker for me next, I think.

 

Edited October 23, 2021 by AstroGee

[happy-kat]

What was your exposure on the Moon with your f22?

I took some single shots with the Moon last week and have stacked them using Registax (planetry stacker) which also has super wavelet sharpening functions.

[AstroGee]

Ta

17 minutes ago, happy-kat said:

What was your exposure on the Moon with your f22?

That particular shot was slow - 1/8sec, f/22, ISO 50. I did take a range of speed/ISO shots, it happened that this was the sharpest (likely due to tripod movement at that focal length).

1/8s is quite slow, there is potential to be sharper with a faster shutter speed I think. I liked the look/feel of this image the best.

Edited October 23, 2021 by AstroGee

[happy-kat]

You did well capturing the Moon at 1/8. It's good to experiment. Faster repeated exposures give greater chance of capturing during moments of less atmospheric disturbance. If possible video is good to use to be able to capture lots more frames as software like Registax stacks the best frames. 

[AstroGee]

10 minutes ago, happy-kat said:

You did well capturing the Moon at 1/8. It's good to experiment. 

Thanks for your encouraging words, to be honest I was quite surprised at the shutter speed myself on that image. There's plenty to explore  here (hence the beginners section) - Looking forward to some winter nights now for a change!

[happy-kat]

As an example I took some a couple days ago17/10  50mm 246mm fl and f4.9 (fixed) and the shutter on the DSLR was 1/500

Perhaps your lens has a sweet spot for sharpness at f8 for working with 

Edited October 23, 2021 by happy-kat

[AstroGee]

2 hours ago, happy-kat said:

Perhaps your lens has a sweet spot for sharpness at f8 for working with 

Yes, I would have gone for f/8 if possible. That's generally the sharpest. In my case the lens was a fixed focal length and aperture, 800mm at f/11. When used with the 2x extender, resulted in effectively a 1600mm f/22. The isn't much light at all by typical standards, but the EOS R was able to autofocus through it... although I was manual focussing for the sky.

 

your shutter speed is more preferable...which ISO setting was that with?

[happy-kat]

F4.9 it was a small refractor telescope I'll have to check tomorrow on iso I did reduce to 100 or 200 but I'll check

 

 

Edited October 23, 2021 by happy-kat

[ItsmeMaw]

I use a Canon SL1, still single images.

Some turn out good, others dont. My biggest issue is still getting a good focus. What I see is not always what I get in the image.

[happy-kat]

I don't know if the new eosr are supported but with the canon 1100d I use I connect to my android phone and use app DSLR Controller to control and focus the camera

[AstroGee]

10 minutes ago, ItsmeMaw said:

My biggest issue is still getting a good focus.

I found this to be very tricky too. Similar to Kat, I used a tether to my laptop - Canon connect I think. Gives a big screen with extra 5x or 10x magnification.

I found that when the focus is just right, the distant stars and moons around Jupiter pop into view. Autofocus didn't find them.

[rickwayne]

Yep. That's even an issue for astro autofocus setups -- if the stars aren't looking like fairly small discs, the system doesn't get any traction on them.

Since focus for the Moon is the same as for stars, the Bahtinov mask technique works quite well. It really does make it easier to fine-tune your focus. Then you can slew to your target and go nuts.

[AstroGee]

11 hours ago, rickwayne said:

That's even an issue for astro autofocus setups

Thanks for that - this is the type of info I hope to learn here.

The other niggles are the slight delay between the remote shooting display and using the manual focus grip. It's probably a combination of the software deal and could also be the fly-by-wire configuration of the RF 800 lens, so it is controlled electronically rather than directly.

I haven't heard of a Bahtinov mask before so I'll look it up. Are there differences in quality/price?

 

[Nik271]

Bahtinov masks are not very expenisve you can make one yourself from cardboard.

I never rely on the autofocus of my camera (Canon 250D) for astrophotography. First manually focus on a bright star using the dispaly at x5 or x10 magnification.

At such focal lengths (1600mm and above) the atmosphere is the main limiting factor. So you need to take many shots and stack  the lucky ones.

Keep the shutter speed between 1/100 and at most 1/500, if you go any slower than 1/100 the air turbulence starts to blur all photos; faster than 1/500 and noise will become a problem.

Also with 1/100 second exposures you don't need a star tracker yet  

Edited October 26, 2021 by Nik271

[happy-kat]

Where possible it's best to choose a star where a third intersects to focus on, this spreads sharpness across the frame better.

[AstroGee]

36 minutes ago, happy-kat said:

Where possible it's best to choose a star where a third intersects to focus on, this spreads sharpness across the frame better.

Great tip and sublime sketching there, thanks!

[AstroGee]

1 hour ago, Nik271 said:

Also with 1/100 second exposures you don't need a star tracker yet  

It's the last word there which might be most significant...

I'll put the other points to use, thanks