Star trail help

[Sahil]

Set camera to "bulb" mode.

Instead of this, how about setting on your camera on Continuous Shots & timer to 30 secs, so as to avoid high noise because of prolonged exposure.
The camera will automatically take another shot after 30 secs. Correct me if this is not how it happens. I haven't tried it as yet.

[Mongwopman]

The camera will automatically take another shot after 30 secs. Correct me if this is not how it happens. I haven't tried it as yet.

I too wish to know this!

[Colin Southern]

Instead of this, how about setting on your camera on Continuous Shots & timer to 30 secs, so as to avoid high noise because of prolonged exposure.
The camera will automatically take another shot after 30 secs. Correct me if this is not how it happens. I haven't tried it as yet.

It's a good theory, but in practice, a star trail can be treated as a high-contrast scene - and as such, you can get quite agressive with the sliders. For moderate length exposures (say, up to 20 minutes) noise at base ISO is still relatively low-level - so raising the black clipping point usually makes pretty short work of making sure it's suppressed.

The issue with taking multiple shots is combining them afterwards ... you can't just average them or stack the layers and change the opacity because the stars are "moving", so you have to use special blending modes where the brighter pixel is allowed to pass through -- and unfortunately, the noise is a "brighter pixel". Not saying it can't be done - but for me, it's usually easier to just try to get it right in-camera.

[Sahil]

Hey Colin,

Yea, I remember you telling me that raising black clipping point helps eliminating noise, but didn't know it could work for shots as long as 20 mins too. Sounds great. Thanks.

[Mongwopman]

Really what Im trying to get froms omeone is a step by step, setting guide for doing this. As im not entirly sure.

Based on what youre saying and also my lack of a battery grip. It would be better for me to take several images and stack them using star trails software, rather than 1 long one because of the 2nd long processing shot that happens.

[Colin Southern]

Really what Im trying to get froms omeone is a step by step, setting guide for doing this. As im not entirly sure.

Best thing I can think of is just practice first!

Based on what youre saying and also my lack of a battery grip. It would be better for me to take several images and stack them using star trails software, rather than 1 long one because of the 2nd long processing shot that happens.

If you can't disable long-exposure noise reduction then you can't combine seperate shots because you'll end up with morse code, not continuous trails.

For a step by step, try this ...

1. Focus on something a long long way away

2. Put a bit of tape over your focus ring (or mark this position in some way) - switch the lens to MF

3. Connect a manual shutter release to the camera and put the camera in bulb mode

4. Open the aperture as wide as it will go (lowest F-Stop number), and select the lowest ISO (100?)

5. Point your lens at the stars (zoom to whatever focal length you choose)

6. Press and hold the button for 10 to 20 minutes

7. If it's cold, don't breathe around the end of the lens as you'll get it covered in condensation.

[Mongwopman]

Hey Colin, thanks for that!

I was messing around last night with light graffiti and I think it's pretty much the same priniciple just a much shorter "window" was interesting to say the least!

Anyhow, I think I now understand the fundementals and cant wait to try it out next month. My 400d can go as low as F3.5 on ISO 100.

Im assuming I can just press and lock when you say press and hold for 20 minutes right?

The camera also does have the option to disable the long exposure noise reduction. I can also lock the mirror etc

[Colin Southern]

Hey Colin, thanks for that!

No worries

I was messing around last night with light graffiti and I think it's pretty much the same priniciple just a much shorter "window" was interesting to say the least!

Yes - it can be a lot of fun ...

Anyhow, I think I now understand the fundementals and cant wait to try it out next month. My 400d can go as low as F3.5 on ISO 100.

Should be OK - if that's not bright enough, try ISO 200

Im assuming I can just press and lock when you say press and hold for 20 minutes right?

Depends on the remote release - I have a TC80-N3 and I can lock the button down on it (but then again, since it's a timer, I usually just set that and let it count down). If you can't lock yours, give some thought beforehand about how you can hold it down with something.

The camera also does have the option to disable the long exposure noise reduction. I can also lock the mirror etc

Personally I disable long-exposure noise reduction as it means I have to wait too long to see the shot (many of mine are 15 to 45 minutes), but up to you. Noise shouldn't be a big problem if you shoot wide open and it's a clear night. Don't worry about MLU (Mirror Lock Up) - I don't think mirror slap is going to affect a multi-minute exposure too much

[koolkat]

OK, I'll try and post a picture that did not make it in a previous post. This is a shot I did in Arizona USA. Canon 400D / Tamron 18x270 lens set at 30MM / ISO 100 / F5 / manual focus / shutter speed 3702 seconds. 9:43p.m.

[Sahil]

Nice try, Mike. It has come pretty fine. Its a well composed shot.
But, IMHO, you could have dome more with PP. I gave it a quick shot. Basically levels & curves.



If you have clicked in RAW format, WB needs to be taken care of.

[victor]

Damien,

I have taken star trail photos using the following:

29 x 30 second exposures taken with a tripod and the remote locked on, mirror lock on.

then combined the photos using the following programme:


Startrails from:

http://www.startrails.de/html/software.html


Sample picture below. From 29 stacked images of 30 secs each.



Hope this helps send me a Private Message if you wish.

Regards

David

[Mongwopman]

So question as this is happening soon, when you have a item in the forground, is that a photo thats taken forst and then the others stacked over that, or is the **** taken with the item in the forground of every frame?

[victor]

Daimen,

The same photograph is taken with your camera on a tripod. The Stars then move as the earth revolves, stacking the pictures, usng star trails "joins up" the stars and shows their movement as an arc ... So each exposure is the "same" but the stars have moved. The program looks after all other details.

Regards

David

[Mongwopman]

Why is when i try and do a long 30 seconds exposure the photo comes out plain white?

[Ken MT]

Sounds like overexposure. Try a shorter time, smaller aperature, or lower ISO. Attached is an image as part of a time lapse of moonrise. ISO 1000, F4, 10 secs, 33 mm on a 28-135 zoom, Canon 30D, taken at 22.00 hrs local time. Note stars showing up.

[Mongwopman]

Ahh sweet! Ok well hopefully im armed with enough info on how to do it. I leave to go Friday so will be posting any hickups if any.

Thanks for help people.

[Nass]

Bit more info here: Startrail ISO reference

[Mongwopman]

So after a week in cornwall, I got 1 night to try this out, this was the result, very choppy. Not sure what to do PP to make it better.

I think I'll have a much better shot in December when im back in South Africa. Sure I have the basics down, just need to tinker with a few things.

[chauncey]

I don't understand why folks don't check MFT charts http://www.canon-europe.com/Support/...ork_iii_en.asp before buying a Canon lens.

[Mongwopman]

anyone care to make some comments of value?