Help please with first long exposures

[Bodger]

Hello,

As a newbie I’d very much like to take some long exposure images (like the attached) but do not really know where to start.  Can you point me in the direction of a good, simple, tutorial.

I have a good tripod, a cable release and a Canon 50D camera with a Canon EF-S 10-22mm f/3.5-4.5 USM Lens, a Canon EF-S 18-200mm f/3.5-5.6 IS Lens and a Canon EF 100-400mm f/4.5-5.6 IS USM Lens.  I also have Photoshop CS5.

I know it will be a long exposure but I’ve read that some people combine multiple images together, using coloured filters, then layer them in software to get an overall image where each layer produces its best effect.

A simple step-by-step tutorial, with lots of pictures, would be brilliant if you could point me in such a direction.

Many thanks

Barry

[Bobby1970]

I am sure plenty of people will be along to advise you. But I have used the following website before and found it very useful

 

http://www.budgetastro.net/

 

Hope this helps. 

 

 

[happy-kat]

^ second that website suggestion covers so much in clear steps plus videos to follow. Shoot in raw. Process using DSS to create the stacked image then fine tune is cs5. To start I'd use your 10-22 mm lens stopped down one or two.

Biggest thing is don't centre star focus instead focus on a third intersection.

 

[happy-kat]

Flats are not optional really so do try to do them. Same focus, same iso, same aperture then just adjust shutter speed to get the histogram peak in the middle. I use my 7 inch tablet as the light source using application lightbox

Lights histogram make sure it is clear of the left edge.

Darks make sure camera noise suppression is turned off. I personally just take a load of bias files there are all settings the same except with lens cap on and use the very fastest shutter speed available.

Dew shield I use a home made shield using flower pot and a rubber band to prevent dew on the lens.

[Bodger]

Many thanks for the quick replies.  I'll follow the link and have a god read.

Barry

[ronin]

Simplest option I know of is along:

Set ISO to 800 - think 800 on a Canon is he "highest" before the noise gets increased also, ISO is a bit odd on digital cameras

Set Exposure time (S) to 20/25/30 (pick one) - catch here is rotation of the sky.

Switch off the Noise Reeduction feauter (somewhere in the general menu)

When outside with it set the camera to Manual (M), Set the focus to Manual. From now on you cannot blame the camera.

Set the lens to around 20mm focal length (EF-S seems ideal) and set to widest aperture and back it off (down) 1 f stop - things are a bit sharper(maybe).

Outside at night manually focus the camera, not so easy, once focused do not alter/touch or move the focus. (May be an indication from the camera for focus even when it is Manual, mine does)

Cover the rear view finder (prevent light getting in), aim at the patch of sky, press shutter release, wait patiently for the exposure to complete. Allow the camera 10 seconds for cooling and to write to memory.

 

That should get one exposure which is likely to be dim. You could waiit 10-15 seconds and take another, and repeat this for say 5 to 10 exposures. Since DSS will stack jpegs you can then try stacking in DSS. You are likely to need to reduce the number of alignmnet stars DSS chooses - cannot recall how/where that is done.

You will have no darks, which are useful, but get the exposures first. Darks need a fridge and an intervalometer is also useful for all this.

An Intervalometer will help for all this instead of a cable release. If you get a tracking mount (or build something) then you can get more ans slightly longer expoosures as the camera will be following the sky better.

[Bodger]

Wow. Many thanks for the information ronin. Much appreciated.

Barry

[newbie alert]

Use the widest lense you own...a invalometer would be better as suggested (cheap on ebay) now is a perfect time without the moon and a very dark sky location ..

 

[Bodger]

Great tutorial packed with lots of information.  Its things like the settings which are most useful as I wouldn't have had a clue where to start.  Many thanks for your contribution.

Barry