Astro Photos & Question

[boost_dependent]

All shot with a a canon 40D


Tokina 11-16 f/2.8 30 sec @ f/4 ISO 800
1.)
http://farm4.static.flickr.com/3586/3578014405_092811f2e5_b.jpg



I got to hook the 40D to an 8" telescope, I don't know any other details about it. It was all in just a few min...
1/13 sec ISO 100 Not cropped at all, just adjusted with camera RAW. I know it's soft, but I didn't have time to figure out the scope. Maybe next time.
2.)
http://farm4.static.flickr.com/3280/3578012797_308afeb87f_b.jpg


I have tried to do star trails before and everytime I put all the exposures together I get spaces in the trails instead of just a continuous streak.
Tokina 11-16 f/2.8 @ f/4 11mm ISO 640
30 x 20sec exposures, used startrails.de to combine.
http://farm4.static.flickr.com/3627/3578817882_96070d229e_b.jpg

[Mike Salway]

Nice work and a great start!

Not sure where the question is though - is it the star trails one?

You need to have less gap between your exposures - that's the only way to ensure you don't get a gap. Each exposures needs to be almost immediately after the previous one. 3 seconds is too long. 1 second should be ok.

Cheers

[boost_dependent]

Well, I had it on continuous drive with the remote shutter button locked down. Would it be better to have the shutter open for the whole time or is the multiple exposures better?

[boost_dependent]

To do a dark frame on these multiple exposures, do I just put the lens cap on and do the same exposure as the other shots?

[jmx]

Yes, but you want the camera to be approximately the same temperature as it was when you took the shots originally. The noise changes a lot in 15 degrees. I think I heard it doubles every 15 degrees F or so.

I dont really think your shots need it tho...dark frames are more important when you're doing long exposures of objects that are real dim, and the noise makes up a significant portion of the signal.

Also I think your camera will do auto dark frame for you on high iso or long shots. I know the 50D does.

[Adrena1in]

Excellent shots there, and I don't think I've ever seen such a dark horizon!!

One question...do you have "In Camera Noise Reduction" switched off? Because if not then each 20s exposure is going to be followed by a 20s pause for the noise reduction to take place, so this would make for a dotted star trail.

[boost_dependent]

Excellent shots there, and I don't think I've ever seen such a dark horizon!!

One question...do you have "In Camera Noise Reduction" switched off? Because if not then each 20s exposure is going to be followed by a 20s pause for the noise reduction to take place, so this would make for a dotted star trail.

Ahhh this makes sense. So, I guess I should turn that noise reduction off when I do star trails? Then just do one dark frame...maybe?

[Bill Boehme]

Very nice moon shot, especially considering that you did not have much opportunity to get familiar with the equipment. There is a tiny amount of CA visibled in the lower and upper parts of the image, but since you shot it in RAW that can be easily corrected if you have ACR or Lightroom. I would suggest a bit of selective USM sharpening on surface features, but avoid sharpening the edge of the lunar disk because it can result in a thin bright white edge around the moon.