23s exposure without star trails -- how ??

[Cerulean]

http://www.uncagethesoul.com/night-photography/best-canon-night-camera/

We set each camera to 25 second exposure, f/3.2, and then worked through the various ISO levels

How come the photos on this webpage do not show any star trails at these settings? I know that to get some stars on my 85mm 1.2L @ f/1.2 I had to do like 8 seconds, whereas at f/2.8 I had to do like 3 seconds. How does time difference not make the one with longer exposure have star trails? Doesn't make sense X_x

 

[Empty_Quarter]

In order to get startrails, you have to stack multiple 30-second exposures, around an hour's worth (example: 120 30-second shots back-to-back). 23 seconds is not enough to generate a star trail.

To get a shot of the milky way, anywhere from 8 to 30 seconds with very high ISO will be able to bring out the faintest of stars. The grain will be horrific, but that's why almost all milky way pics are shown at low-res, you'll rarely come across a crystal clear high-res milky way shot.

 

[Cerulean]

In order to get startrails, you have to stack multiple 30-second exposures, around an hour's worth (example: 120 30-second shots back-to-back). 23 seconds is not enough to generate a star trail.

To get a shot of the milky way, anywhere from 8 to 30 seconds with very high ISO will be able to bring out the faintest of stars. The grain will be horrific, but that's why almost all milky way pics are shown at low-res, you'll rarely come across a crystal clear high-res milky way shot.

If I do a 23 second exposure on my 17-40mm, there will be noticeable star trails. Short, true, but there is visibly obvious trails.

I'll have to go redo my shots to confirm this, but I feel that I've encountered different results on different lens on the same settings. Is the image supposed to be the same or different if you use the same settings but different lens?

 

[patric]

Use a wider angle lens. As a general rule you can divide 1000 by the focal length of your lens. The number you get is the maximum exposure in seconds you can use before seeing star trails. If you're using a crop camera divide that number by 1.6 first.

 

[staticlag]

The only way to get these type of astro-photography pics is with a equatorially aligned mount. He doesn't mention it because he wants to try and "WOW" people with his leet skills I'm guessing.

You can homebrew one for like $50. It's very limited and only works for wide angle lenses. It's probably what he used. Then he had his buddy move to foreground and popped his flash quickly to give the effect that this was one shot taken in real time.

Otherwise the commercial mount itself starts at like $1k for pro quality star pics.

 

[staticlag]

Here's the classic DIY most newbs use: (probably what this guy used)

http://www.philharrington.net/scotch.htm

 

[Cerulean]

The only way to get these type of astro-photography pics is with a equatorially aligned mount. He doesn't mention it because he wants to try and "WOW" people with his leet skills I'm guessing.

You can homebrew one for like $50. It's very limited and only works for wide angle lenses. It's probably what he used. Then he had his buddy move to foreground and popped his flash quickly to give the effect that this was one shot taken in real time.

Otherwise the commercial mount itself starts at like $1k for pro quality star pics.

Thought I would mention this, as last night I also wondered about how 51200 ISO would look on a Canon 1DX considering how bad 6400 looks on my T3i, and I had found the article I linked to in OP. As you get to the bottom where he approaches the very high ISOs... literally nightvision

The reason I wondered is not so much to impress anybody but because my camera can see more than my eyes can and better with more detail, and seeing the results is awe'ing. Perhaps I should get a telescope.

 

[madFive]

Also note that the photos in link were taken with a 14mm lens, not 85mm. They're not zoomed in near as far, so you're not going to see as much motion-blur. On the 100% crop images you can see a tiny bit of motion blur, but it's essentially un-detectable when zoomed out.

 

[Cerulean]

Also note that the photos in link were taken with a 14mm lens, not 85mm. They're not zoomed in near as far, so you're not going to see as much motion-blur. On the 100% crop images you can see a tiny bit of motion blur, but it's essentially un-detectable when zoomed out.

I have a question regarding the focal length, wanting to just confirm my knowledge, but the 14mm they used would be technically fisheye/almost fisheye/ultra wide angle, or no?

 

[madFive]

Yeah, that's about as wide as you can go on a full-frame without going fish-eye. The one used in the linked artical is not a fish-eye, just an ultra-wide prime.

 

[patric]

I have a question regarding the focal length, wanting to just confirm my knowledge, but the 14mm they used would be technically fisheye/almost fisheye/ultra wide angle, or no?

It's an ultra wide angle, but it's not a fisheye. With a 14mm lens on full frame you can take close to 1 minute exposures without tracking and unless you start pixel peeping you won't notice any star trails.

With my 10-22mm zoom I got some pretty good results with 30 second exposure times. I'm kinda excited to see what I can do with my 6D and it's high ISO ability this summer when the milky way becomes more visible.