Cameras and focussing

[Bongo]

Hi,

I have a modest telescope (see footer) and have recently had a go at some photography. Using an aging DSLR and a 2x Barlow I was able to get some OK-for-a-beginner's-first-attempt pics of Jupiter, and some nice moon pics (see attached). I don't expect amazing photography with my set up, my goal is to be able to show family and friends what I'd seen through the 'scope with my own eyes.

One of the problems I have is focussing - through the viewer of the DSLR, Jupiter is a tiny, bright speck and its hard to tell whether its in focus or not. I tend to guess, take a photo, view it on the cameras screen, zoom in, adjust focus and repeat until its 'near enough'. Is there a way of doing this more precisely and/or quicker?

Also, if I was to invest in a 'proper' camera e.g. one of the cheaper ZWOs, would I be able to preview images live on my laptop? I guess it would be easier to see if I was in focus on a bigger screen.

Any and all tips welcome! Thanks in advance.

[Mandy D]

@Bongo What DSLR do you have? Most recent (manufactured in the last 15 years or so) DSLRs have live view, where you can zoom in and focus using the LCD on the rear of the camera. If you can tell us which one you have we can probably help much more.

[Bongo]

2 hours ago, Mandy D said:

@Bongo What DSLR do you have? Most recent (manufactured in the last 15 years or so) DSLRs have live view, where you can zoom in and focus using the LCD on the rear of the camera. If you can tell us which one you have we can probably help much more.

Hi! Thanks for your reply. Yeah, it really is an aging DSLR - a Nikon D40 - and as far as I know it doesn't have live view. It was languishing unused in a drawer si I thought I'd try to put it to some use. 🙂

[Mandy D]

5 minutes ago, Bongo said:

Hi! Thanks for your reply. Yeah, it really is an aging DSLR - a Nikon D40 - and as far as I know it doesn't have live view. It was languishing unused in a drawer si I thought I'd try to put it to some use. 🙂

Digicam Control supports D40. You should get live view on screen with that. You'll just need a suitable USB cable.

 

https://digicamcontrol.com/cameras

Edited December 12, 2023 by Mandy D

[Bongo]

2 minutes ago, Mandy D said:

Digicam Control supports D40. You should get live view on screen with that. You'll just need a suitable USB cable.

 

https://digicamcontrol.com/cameras

Aaaaah! That's interesting. I'll take a look. Thanks.

 

[Elp]

If you connect it to a computer controller or software like NINA or APT it may have the capability to live focus, live focusing with a DSLR is a little slow as you have to wait for the shutter mechanism between exposure samples whereas an astro camera is near real-time. I've done it via an Asiair when I had my Canon 600D.

You can continue doing it how you are currently, take an image then check the image and zoom in, it's how I usually use a camera body but for planets it's a bit more difficult because the atmospheric seeing distorts the view constantly. You may also have more of a chance freezing seeing on planets taking video rather than stills.

Edited December 12, 2023 by Elp

[Elp]

An astro camera will always be better, the right tool for the job, and they'll have high FPS capture rates for planetary, the sensors tend to be smaller for the planetary models compared to dslr sensors so you'll get a crop factor "zoomed in" view.

[900SL]

Look up ' Bahtinov mask'

[bosun21]

Bahtinov masks are not ideal for planetary imaging and you are much better focusing on the planet itself like the bands on Jupiter. A dedicated planetary camera will allow you to focus on the live preview and hone in on the details on the planetary surface. For DSO's a Bahtinov mask is the correct choice. Good luck.

[PeterC65]

I'd recommend using a Bahtinov mask. Make sure you can see the cameras image on a laptop while being able to adjust focus (I'd recommend using SharpCap software for this). Put the camera into live view mode and try to get a frame rate of at least one per second. Pick any bright star and centre the scope on it with the Bahtinov mask fitted. Zoom in on the star so you can easily see the Bahtinov mask lines and adjust the focus to get them right.

I find this far easier than any other way. For the Moon and Planets just focus on a star first.

If you leave the scope to cool for 30 minutes and don't change the setup it will remain in focus all night.

 

[Bongo]

Plenty of things for me to try there. Thanks everyone!

[bwj]

You might also look up "Backyard EOS". They have a free trial version.