Shooting the night sky

[jsecordphoto]

Did you zoom in with your lens or on the screen? Zooming in with the lens to check focus isn't the best thing because of focus breathing.

 

[Synax]

Did you zoom in with your lens or on the screen? Zooming in with the lens to check focus isn't the best thing because of focus breathing.

I zoomed in x5 on screen then again on x10. Made sure the light was like a bright smaller dot and that's how I got my focus.

 

[pgriz]

OK, using the 10x magnify option on live-view is different from zooming the lens. There are a few lenses that are parfocal (the focus point is maintained throughout the zoom range) but most have to be refocused if you change your focal length (as Jsecordphoto mentions above).

Another "trick" you can use to help you acquire focus at night, is to increase your ISO to some very high number, and live-view will display the "simulated" vision, which will be much brighter (because of the high ISO) than normal. Once you've acquired the focus and locked everything down, you then revert to your intended ISO for shooting.

However, if you're including some foreground material that has to be included in your depth-of-field calculations, then determining the appropriate focus point is more tricky.

 

[Synax]

OK, using the 10x magnify option on live-view is different from zooming the lens. There are a few lenses that are parfocal (the focus point is maintained throughout the zoom range) but most have to be refocused if you change your focal length (as Jsecordphoto mentions above).

Another "trick" you can use to help you acquire focus at night, is to increase your ISO to some very high number, and live-view will display the "simulated" vision, which will be much brighter (because of the high ISO) than normal. Once you've acquired the focus and locked everything down, you then revert to your intended ISO for shooting.

However, if you're including some foreground material that has to be included in your depth-of-field calculations, then determining the appropriate focus point is more tricky.

Hmm.. So.. What I'm doing is reflectively correct or not?

 

[pgriz]

Hmm.. So.. What I'm doing is reflectively correct or not?

Can't really say. Maybe you need to tell us exactly what you're doing. For example, something like this:

Camera on tripod.
Lens AF turned off, IS turned off.
Focal length set to (say) 80mm.
ISO set to (say) 32000.
Aperture set to (say) f/4
Mode dial set to M (manual)
Shutter speed set to 30 seconds.
Lens manually focused to approximately the infinity mark.
Live -view activated.
Camera pointed to (say) Jupiter.
Manual focus adjusted until Jupiter looked like a small point of light.
5x magnify option on live-view engaged, focus adjusted.
10x magnify option on live-view engaged, focus adjusted.
Move camera to desired field of view (without changing aperture, focal length, mode, AF/IS, or shutter speed).
Change ISO to (say) 800.
Activate shutter.

(post resulting image).

 

[Synax]

It's raining pretty bad tonight so i can't go out and do all of that. I took some pictures last night though with the focus method I'm talking about. One picture is edited, the other one isn't. I sort of like it... I think it turned out pretty good but who knows haha

 

[jsecordphoto]

they're definitely much better.

 

[Synax]

Awesome. Does the focusing look alright from the unedited picture? Or can I do better?

 

[pgriz]

Focusing looks good. You've got a bit of trailing, but that's the "learning to walk before you run" part. And you've imaged the Adromeda galaxy in the upper left power point. What were your exposure settings (ISO, aperture, shutter speed, focal length)?

 

[Synax]

So I guess there is an online thing for that... I was going to go tomorrow night, write everything down, and try to take a nice picture. I guess I don't have to? Does this show a clear summary of what you guys want? This isn't the raw image... I converted it to jpeg with light room.

This was from the image I posted.

 

[wfooshee]

Another thing I meant to suggest is white balance. For night skies you'll want the WB quite low. No more than 4500K, maybe down to 3500K.

 

[Synax]

I was reading about white balance the other day. Mostly about night painting, but I didn't know that piece of info about night sky shooting. I'll try messing around with that tomorrow.
Thanks!

 

[pgriz]

OK, setting look good. Now up the ISO to 3200, reduce your shutter speed to about 1/10 sec and see how it looks. After you've got that all figured out, you'll need to get some darker skies and practice.

 

[Synax]

Can't go more than 1600 ISO sadly . That's as high as I can go on my Cannon 40d. Unless you mean by using the ISO expansion?

I also took this picture, but sadly the original one was light over kill so this one is edited...

ISO 1600, F4, 20 minutes or so... haha. Probably due to the high ISO...
Should of done a lower ISO and a higher aperture correct?

Original one...

 

[jsecordphoto]

you'll continue to get star trailing with these settings, because your lens isn't wide enough to shoot for 30 seconds. With your lens, with crop factor, you can do about 11 seconds before you'll get star trailing. You're getting much better results than before, but you'll never get pinpoint stars with those exposure times.