Help using R5 for astrophotography

[Ozark-Bill]

Hi everyone,

I have used Canon dSLRs for years for doing astrophotography, including deep sky and nightscapes. Over the past couple of years, I have tried to get my R5 involved, but have not been able to solve a problem I am having. The issue is not being able to see enough stars to acquire focus. When using both the back screen and the viewfinder, only the brightest planets/stars will be bright enough for me to see and to use for acquiring critical focus. For something like a wide angle nightscape, this is doable most of the time. However, for shooting deep sky objects, this makes it impossible. I am a low-tech astrophotographer and do not use any type of "go-to" apparatus. So, being able to see the dimmer stars is critical for the star-hopping I need to do to find some of the trickier DSOs that are not visible to the naked eye.

I use very fast lenses and I have tried it both with exposure simulation turned off and on. I assumed this was the issue, but it doesn't seem to make any difference at all. I have also tried using the highest possible ISO settings, thinking this would help with the sensitivity on the screens, but have not had luck with this either.

There must be some setting that I am overlooking, or there is something wrong with the camera. I appreciate any thoughts you'd care to share. 

[johnrmoyer]

I have EOS R5, but am no expert on astro. I have photographed Jupiter and a few of his moons using auto focus.

I have photographed Orion's belt by using manual focus and the manual focus aids in the camera and the viewfinder.

I have used the Canon app on an iPad or an android phone as a remote trigger

Maybe focus manually on something bright like Jupiter, Saturn, or Venus or even a bright star and then move the camera to point in the direction interest?

Focus might change as the camera warms up. Auto focus on a bright star might get it close enough to infinity to autofocus on a dimmer star. I start with center focus area.

[mandritoiu]

I'm facing the same issue with the R7.

I'm disappointed that the so-called exposure simulation is not simulating long exposures.

Canon should add a live view gain boost to make star focusing possible even with slow lenses.

[Waddizzle]

Are you using Bulb mode?  ExpSim does not work in Bulb mode. How would the camera know what shutter speed to allow for. 

[mandritoiu]

I used manual mode, ISO 6400, f/8, 10s.

I also tried Aperture Value (AV) mode. The only option I had was to take a photo (which was much brighter than live view), focus, then repeat. After that, I had to guess the Andromeda position in the sky and do the same until I framed it. Very tedious.

I read that a camera reset might address the problem. I did it, and it seems like it may be true, although I will test it again tonight.

[shadowsports]

Greetings,

I'm curious to know what lenses everybody's using?  "Fast lenses" does this mean Canon or another brand?

[Finelld]

I have used canon cameras to do a variety of types of astrophotography and especially like the deep sky objects.  While I do have a go-to setup I always use a secondary scope for guiding.   The secondary scope will provide a wide enough field of view to see bright enough stars especially if you are doing star hopping to locate your object.  As nearly all stars are at an effective infinity focal distance it doesn't matter which one you focus on so long as the focus remains set as you move between targets.  so find a bright star to set your focus on then move to the dark sky object you are wanting to image.  I use a C-8 and an Orion ED80 for imaging scopes and a William Optics 66sd for the guide scope.