This was an old forum post that my friend Ian initiated. I thought I’d post it here. It’s pretty good!
I’m currently looking into purchasing a lens or two for my canon rebel sl1. I’ve taken an interest in landscape photography, so a wide angle seems appropriate. I would also like to pursue astrophotography. I’ve been doing some research on lenses but would really appreciate some feedback on what you all think.
How significant will the difference in quality be with astrophotography when comparing lenses that can open to 1.4 aperture vs. 2.8? I ask because I’m torn between getting what seems like an all around lens that can do everything fairly well like this Tokina. Or should I invest slightly more $$ into two lenses; one specifically for wide angle landscape like this Canon, and one designed for astrophotography like this Rokinon – check out the amazing star photos this guy gets with this lens Youtube.
Thanks for any feedback!
Reply from Jay: Excellent question Ian. And might I also add, very well written!
Okay, so here’s my opinion. I guess we need to get past the fact that we’re not going to find a sweet F/1.2 10mm wide angle lens for $300. That’s a given. I just did a quick look and found a 24mm F/1.4 for about $1500. Any wider than that will only get more expensive. There seems to be dozens of 10mm Canon or Canon-fitting wide angle lenses at F/2.8, F/3.5, and F/4.5 apertures in our price range, but those won’t do what we want when it comes to astrophotography. So we need to put the dream of cheap star photography to bed. Not that you can’t get it reasonably priced, but out of one lens? No.
For regular daytime and dusk wide angle photography, I’d personally pick up the Tokina you referred to. It’s very wide, has a quiet auto-focus motor, which matters for any type of video you’ll be shooting and the aperture is actually pretty wide. You’ll be able to get some nice shots during the blue hour, that’s for sure. I just checked and it fits your camera. The only problem is, it’s currently listed for $379. I think I saw it used for $299 a while ago. That’s why I put this one in my Amazon shopping cart. It’s been sitting there for about a year.
Whoops, it’s actually selling used on Amazon right now for $298. That’s a great price. And that comes with free delivery.
Moving on. Here’s the problem with star photography. The primary issue has to do with very little light in the atmosphere. Because of this low light, you’ll either need to step up your ISO values, which will result in tons of grain, or you’ll need to decrease your shutter speed so the shutter stays open for longer than 30 seconds. As I mentioned to you, longer than 30 seconds causes light trails and I’m sure you don’t want that. Take a look at these star photos I took a while ago. You most likely can’t see it, but they’re full of grain. It’s terrible.
As I stated in the post, I captured these images with my Canon 24mm F2.8 lens. While the coverage was okay, the amount of light allowed into the lens was no where near sufficient. I wasn’t even going to try with my Sigma 10-20mm F/4. The photos would have come out horribly.
The only other place you can look for light is your aperture, so you’re definitely on the right trail when it comes to that. The Rokinon lens you linked to above seems like it’s got good reviews. I definitely wouldn’t go any smaller than F/1.4 though. I’d love to see an F/1 or F/1.2 someplace in the same price range. Or even something a bit wider than 24mm. The focal length sometimes doesn’t matter too much because of the way the manufacturer bends the glass, so you’ll just need to check out the sample photos in the reviews.
Another reason you’ll likely need a dedicated astrophotography lens is because you’re eventually going to want to capture the Milky Way (like in the sample review shots). That’s super low light and only a huge aperture will get you there.
Now that we’ve pretty much decided on a great daylight wide angle lens (I’m so presumptuous), are there any other options for astrophotography lenses that you like? Maybe three different models that we can analyze?
If this were me, I would pick up the Tokina first to practice with. You can do both star shots as well as regular wide angle photography. Then, once you’ve gotten bored with that, look into getting the purely astrophotography lens.
PS – I would choose the Tokina over the Canon for regular wide angle landscape. It’s got a larger aperture and that’s just awesome to have.
Oh yeah, one more thing, I’m wondering if laurag can post a few sample shots that she took of the lake the other day with the Sigma 10-20mm. With our cropped sensors that our cameras come with, the 10mm will essentially be seen as a 16mm, but that’s still super wide. With a 24mm lens attached to your camera, you’ll be seeing what a full frame camera would see at 38mm. Be careful here because those sample shots you’re seeing on the Amazon page may have been taken with full frame cameras. You may not see similar results. Yours may be much more narrow.
Photos from LauraG:
Reply from Jay: Okay, Ian and I went out the other night to test out his lenses. Here are my shots with the T7i. I was using the Rokinon lens. If memory serves, my settings were as follows:
Shutter Speed: 13 seconds
Focal Distance: 24mm
2 second timer
Here are some sample shots with this lens. I took a bunch more, but the lens wasn’t in focus for the beginning shots. I fixed that and continued on. Also, I lightly edited these shots in Adobe Camera Raw.
Overall, I really liked the lens. The focus is very sensitive so that needs to be set during the day when you can see what you’re doing. When you find the proper setting, tape the lens so it doesn’t move. Also, since this is a manual aperture setting, do that during the day too. Obviously, since you’ll be doing night star photography, you’ll want to use the widest f/1.4 setting. I would have loved to have had this large aperture with a 10mm wide angle, but we can’t have everything. Ian will hopefully post his sample shots as well. He was using the Tokina 10-16mm.