tnick771 wrote in post #18111889
So I've done a lot of reading, and last summer I was presented with an infinite blanket of night sky with countless stars and my camera, a tripod and a desire to capture what I saw.
What I had read was to take your lens and turn it just before infinity on the focus dial, set exposure for 30 seconds, crank the ISO up to at least 1600+ and then use a remote to avoid camera shake.
My photos were a disaster.
Does anybody have a near-fool-proof "recipe" for astrophotography?
I use a Canon DSLR, a 10-22mm Lens (could use another if better?), a tripod and a remote.
Just something else to think of, since a lot has already been covered, here's something that I would call 'fool proof' from experience:
I used to just use a 650D (T4i) with a Tokina 11-16 F2.8 lens on a standard tripod, didn't even use a remote shutter. It didn't matter if I put the Tokina at 11mm or 16mm, or any focal length in between. I simply turned it's focus throw to infinity, left it at F2.8, and set my time to 20 seconds. The only thing I adjusted was ISO. I usually just shot it at ISO 1600 or sometimes ISO 3200. I never had to focus it, never had to worry about exposure beyond using one of those two ISO values. Just pointed it in the general direction I wanted, and hit the shutter button to expose it (I used the built in 10 second timer to avoid shaking it while pressing the shutter).
It was truly bullet proof in the sense of just walking out, setting it up, and exposing. Not having to worry about time, aperture, not worrying about focus at all, etc. Amazingly easy. Really enjoyed it.
Since then, I moved to a tracker and it really changes time for exposure as a limitation, so you can use more lenses (like slower ones) and longer focal lengths, etc. Big time game changer. But it also requires alignment, money, time, etc. It is not fool proof, it just adds complexity, but it also opens a lot of doors to progress forward.
Exposure time is a big deal for the night sky, you have to get enough data to process. But, the longer exposure time is limited based on your focal length & sensor size's relationship (with respect to the time it takes for an object to move a significant amount within an arc; this is where the common 500/focal length(1.6 if aps-c) = seconds of exposure time before trails happen, comes into play). I use 500/focal length(crop factor) because it's a lot safer to avoid trails than 600/focal length(crop factor). But this means you have to use wider angles to get enough exposure time if you want to avoid trails.
Aperture helps a lot, but you don't have to stress getting the widest aperture possible, it helps, but it also can be harder to use (such as achieving focus, and dealing with bad CA around stars, etc).
ISO is your friend, crank it up, don't be afraid to top it out, just test things. You can clean up more than you might think!
Achieving focus is the other big deal, since out of focus stars are just fuzz. Do this in Live View, magnify 10x on a big star, and focus it manually (turn off AF!) until it's as pin point as possible. Another option is to get a Bahtinov mask (they're cheap) and put it over your lens while you focus in live view and focus it that way (google it, it's easy, and works great, takes a lot of guess work out of it; easy $15 accessory that works wonders).
The biggest deal is to practice!