topic Re: EOS R5 Mark II Astro photos - not coming out well in EOS DSLR & Mirrorless Cameras

EOS R5 Mark II Astro photos - not coming out well

Samtata2024 — Wed, 30 Jul 2025 12:49:51 GMT

Hi everyone,

I have been trying to take some astrophotography. I have a R5 Mark II - my settings for these pictures are Manual focus, 15 - 35 mm f2.8 lens.

the picture settings I had at 15 - 20 sec shutter speed, ISO 3200, and f 2.8. I thought 3200 is a good ISo but im still seeing so much pixelation and blur.

Re: EOS R5 Mark II Astro photos - not coming out well

kvbarkley — Wed, 30 Jul 2025 13:00:16 GMT

20 seconds is when you willl start to see motion blur from the sky’s rotation. You need a tracking mount.

i assume you have a good tripod

Re: EOS R5 Mark II Astro photos - not coming out well

johnrmoyer — Wed, 30 Jul 2025 13:26:04 GMT

Also, star blur from rotation of the earth will happen at a shorter exposure with a 45 megapixel camera than with a 20 megapixel camera because the pixels are closer together.

The manual focus peaking assist feature seems to help if there is a bright object in the field of view.

Re: EOS R5 Mark II Astro photos - not coming out well

Waddizzle — Wed, 30 Jul 2025 15:52:52 GMT

I agree with my colleagues. You are seeing star trails because the shutter speed is too long.

The rule of thumb says that the maximum shutter exposure time is determined by the focal length in use. 500/FL

Re: EOS R5 Mark II Astro photos - not coming out well

Waddizzle — Wed, 30 Jul 2025 16:02:15 GMT

Apply the formula to the 35mm focal length works to just over 14 seconds. Use 13 seconds. The 15mm focal length works out to just over 33 seconds. Use 30 seconds.

Re: EOS R5 Mark II Astro photos - not coming out well

Samtata2024 — Wed, 30 Jul 2025 18:15:27 GMT

actually ia gree with teh star trails but that was not what i was referring to - if you look at the bottom of the photo with the bushes or if you just zoom in - the picture is heavily pixalated - like static even though i was max at 3200 iso

Re: EOS R5 Mark II Astro photos - not coming out well

jrhoffman75 — Wed, 30 Jul 2025 19:25:39 GMT

https://focusonlens.com/calc/calculators/astro.php
This is the formula that should be used with modern digital cameras.
Have you processed the images you posted; what software did you use to render the RAW files?

Re: EOS R5 Mark II Astro photos - not coming out well

Waddizzle — Wed, 30 Jul 2025 20:37:11 GMT

“ https://focusonlens.com/calc/calculators/astro.php
This is the formula that should be used with modern digital cameras.
Have you processed the images you posted; what software did you use to render the RAW files? “

Thanks, for the interesting link, John.

———————

I neglected to mention that the formula I posted assumes ISO 100. John’s link seems like it would give better results.

I entered focal length and aperture. The tool calculated ISO and shutter speed.

If you divide ISO by 16 and multiply SS by 16, then you get the same result as the formula. The formula reports the longest exposure time, not necessarily the best exposure.

What I like most about John’s link is the shorter SS. You can capture several and stack them. Just keep the total length of the series of stacked exposures under the maximum time provided by the formula, 26 seconds.

Re: EOS R5 Mark II Astro photos - not coming out well

Samtata2024 — Wed, 30 Jul 2025 20:42:26 GMT

thank you everyone ! seems like i need to reduce my exposure time and perhaps the blur is because i am increasing exposure. in post processing without stacking i.,e trying to show the green in the bushes whilst still showing the milky way

Re: EOS R5 Mark II Astro photos - not coming out well

jrhoffman75 — Wed, 30 Jul 2025 20:53:58 GMT

If you are using Lightroom or Photoshop try boosting the shadows rather than the overall exposure. You could even try the landscape mask and select vegetation.

Re: EOS R5 Mark II Astro photos - not coming out well

Peter — Wed, 30 Jul 2025 21:39:21 GMT

The pattern seems to be from the lens correction.