1100D Focus to Infinity

[lw24]

Hi,

I recently bought a Canon 1100D with 18-55 kit lens for some static tripod widefield astrophotography. I read a while back some steps on how to do widefield astrophotography, and I can remember one of them saying 'set focus to infinity'. How exactly do I do this? I understand how to manually focus, change exposure time, ISO etc, but this - I don't understand. There aren't any markings on the focusing ring either.

Any ideas?

[Gina]

As I understand it the modern Canon lenses don't have a Manual Focus facility but probably someone else will know for sure.

[VigdisVZ]

Here is how I do it on nikon with a very similar lens, and even if you have a lens with infinity marking, you still should do it manually since the markings are never that precise.

1) Mount the camera on the tripod.

2) Set the focus to manual.

3) Enter live view.

4) Target a very bright star, planet or the moon (or a radio mast/streetlight/bright thing a few hundred yards away).

5) Digital zoom your live view picture onto said object.

6) Twist the focus ring until you get the object as un-fuzzy as possible.

After this your focus is set, make sure you dont touch the focus ring by mistake after this, or you'll have to refocus.

This is an example of the result i've achieved with this method:

Hope this helps! Looking forward to see what beautful shots you capture.

[lw24]

Thanks a lot!

[Gina]

The Canon lens I've got hasn't got a focus ring! I haven't used it for AP yet. It's a zoom and I prefer prime lenses for AP. I'm using film SLR camera lenses for my wide field.

[Digz]

You cam make a simple 'Y' mask with string or card and mount I front of the lens. This will help getting accurate focus described by Carl above.

some masking tape can then help secure the focus once achieved.

[VigdisVZ]

The Canon lens I've got hasn't got a focus ring! I haven't used it for AP yet. It's a zoom and I prefer prime lenses for AP. I'm using film SLR camera lenses for my wide field.

I thought so at first, but the focus ring is the outermost part of my Nikon lens. I just doesn't have any markings. I am not going to call shenanigans, but having no manual focus seems really really strange.

Edit: Oh and congratulations Gina on 10000 posts!

[Wobbly Bob]

Most of my Canon len,s have a focus ring, usualy at the front.

[Steve Ward]

I would use the focus control in EOSUtilities and focus that way , providing you're using the camera connected to the laptop that is .

The modern lenses all tend to focus beyond infinity and they are aimed at Autofocus use and tend to have very "loose" focus rings , the one on the kit 18-55 I got with the 1000D is next to impossible to focus manually .

Steve.

[jon1000]

Thanks for this.