focusing tethered EOS camera/lens for astro

[troypiggo]

Given my recent faux pas (http://www.iceinspace.com.au/forum/showthread.php?t=122804), while considering the very generous offers from some fellow IIS'ers to borrow their CCD cameras, I'm also considering using my Canon 5DII and perhaps using lenses (eg my 135L) and wider field imaging for something different.

I'm all over the image capture side of things, and when I've used the 5DII for astro it's been star trails or landscapes, not tethered to computer so focusing manually.

I have EOS Utility, and it does allow to remote live-view focus. I just did some practising inside the house. But I'm curious about in the field and focusing on stars. If you do this sort of shooting, how do you achieve focus?

[h0ughy]

laptop and blow the bugger as large as on screen, and use a bhatnoff mask? once done you can image and capture on the computer or go back to an bulb and do it that way.

[traveller]

Backyard eos has a focusing feature.
Never tried it with canon lens though...

[Ryderscope]

Agree with Dave. I use the 60Da and Skywatcher 100mm APO. Also use Backyard EOS for capture. There is a 5x setting in EOS and then I set the image (in live view) to full screen in Backyard EOS. Silp on the bahtinov mask and focusing is accurate.

[troypiggo]

Thanks guys. EOS Utility has a zoom and live view so might just use that. Need to knock up a baht mask for lens, though.

[Octane]

You can also focus your lens directly in EOS Utility. :)

H

[troypiggo]

Yeah mate. That's what I think I'll do. Baht mask and EOS Utility. Only pain will be having to disconnect from the image capture software, run EOS Utility, focus, then close EOS Utility, then reconnect the image capture software.

[Octane]

Just use the intervalometer in EOS Utility. It's all I used to use. :)

H