I have been using the 50mm f/1.8 II on my XSi for about two months now, and while it's awesome for portraits when it focuses, I am getting a lot that's not. Granted, I shoot at f/2.8, which is already pretty shallow, but I have seen people who can get super sharp pics at f/1.2! My XSi doesn't have focus problems, because the kit lens is sharp (although it's also got narrower aperture...)
I noticed with my lens, is that when shooting a person, I can stand close for a head shot, it will be in focus nicely. Or when I am using flash, and the flash shoots out the red lines to help focus, it is pretty accurate. The picture may actually be too sharp!
However, when I am standing far away to shoot a full body shot, it doesn't seem to want to focus. I use center focus point, and I think the micro focus thing is working at f/2.8, but about 60% of my pics don't come out sharp. Is the distance hurting it? I think it's ok because sometimes it will still focus very accurate when using live view contrast focus.
I am wondering if there are any tips you have with this lens? Or should I get a better lens because USM will give me a better focus? I plan on getting the 70-200mm f/2.8 IS anyways, but I'd still like to use the nifty fifty. Unless I upgrade to the f/1.4 one... Thanks!
Honestly: Need help with reliable focus on 50 1.8
This is a bit of an oxymoron. That's simply the truth. The 50 1.8 is a great lens but it is a compromise lens. The biggest of which is its AF system.
I know that, but I have gotten a few really nicely focused and sharp photos from it, and other people too, so I know that although it's not the best, it's still capable of delivering.
I just don't know how to make it work ~90% of the time. Should I not use center focus? Should I not lower than certain shutter speed? Should I always use flash? Should I sell it and buy a 50mm f/1.4 instead? I really like the shallow DOF it provides...
The lens is sharp but it's not the best auto focusing lens out there. If you want to be sure your pictures are sharp, make sure they look so through the viewfinder. How you achieve that focus with the AF system is largely dependent on what the subject is.
Well, my XSi doesn't have the best view finder in the Canon line up... it's kinda small compared to the view finder on say, a 5D, so it may look like it's in focus in my VF, the picture doesn't come out so.
I shoot people 99% of the time. I guess I will throw up some examples from the shoot I did this past weekend later tonight (I am at work right now).
I never had an issue with focus accuracy and this lens. I think it may just be your first really fast lens? You really have to remember that when shooting people hand held, both you and they are moving a little bit and just swaying an inch or two will cause blown focus if you locked in the second before.
With center focus and recompose you have inherent innacuracies, but still it is often the best, you just have to live within the limitations of shallow DOF.
To test the lens and your camera, tape some newspaper to the wall, put your camera on a tripod and shoot 5 images, defocusing in between shots. If all the images look sharp then the camera/lens is focusing repeatably and your problem is in how you are shooting.
The camera needs some high contrast edge to focus on, maybe you aren't getting this at distances.
Honestly, I found the 50/1.4 to be *slightly* worse for focus accuracy on my different bodies... maybe just coincidence with my shots... I think a lot of people upgrade to the 1.4 and think the lens fixed their problems when the reality is that they just got better by the time they did the upgrade.
The nifty fifty is crap shoot for focusing at the wider apertures. I know I can only *nail* the focus on my XT/50mm 1.8 on about 1 out of 3 shots when shooting @ 1.8. (Damn small viewfinders!)
Ha ha thanks guys... I think I shoot at fast enough shutter speed to eliminate blur, but I do recompose...
I will give that test a try. I will probably have to try at different distances too. It's just frustrating to go home, load the images, and to find that a good image is blurred at 100% crop. Maybe I will just show the small versions of those to trick people into thinking they are sharp...
mh2000 wrote:
Honestly, I found the 50/1.4 to be *slightly* worse for focus accuracy on my different bodies... maybe just coincidence with my shots... I think a lot of people upgrade to the 1.4 and think the lens fixed their problems when the reality is that they just got better by the time they did the upgrade.
Tim Speciale wrote:
You could also, if you can afford it, treat yourself to a 50mm f/1.4. You may just be surprised what a difference it can make...
I guess it's one of them YMMV things... Well, I am gonna the 70-200mm f/2.8 IS first, which has USM, so I should get better focus with that... I hope...
The 70-200 is better in so many ways, with two exceptions. It doesn't shoot at 1.8 and it isn't a 50mm lens...any other way imaginable i'd take the 70-200
4honor, are you using AI servo or One-shot focus on your images? It may help to switch to one-shot and lock focus on your subject. Sometimes even slight movements with the servo can change the plane of focus, which will result in bluriness at such a low aperture as f1.8
mdude85 wrote:
4honor, are you using AI servo or One-shot focus on your images? It may help to switch to one-shot and lock focus on your subject. Sometimes even slight movements with the servo can change the plane of focus, which will result in bluriness at such a low aperture as f1.8
Thanks for the response, but I am using one shot focus. I just recompose... Not much though...
I dunno 4honor, I have been using the f1.8 for about 5 years with pretty good success.
Think of 1000px long photo of a face, where the distance between the two eyes is 700 pixels so there is 700 pixels worth of detail. Now think of a 1000px long photo of 10 people standing side by side. Now the distance between one person's eyes might be 50 pixels. The detail is just not there because the subjects are much farther away and the resolution the sensor can pick up is much less. Perhaps that's why the photos seem a little softer. I find that the 50 1.8 works optimally at a distance of 5-10 feet, anything longer than that and I am better off using a zoom lens.
Yeah... that's what I am thinking too... When I am looking through the view finder, up close, my red focus dot is on the eye ball, but 10 ft away, the red dot covers the whole face, so maybe it can't focus right...
But my problem is then, I need full body shots, which means the head is gonna be small no matter what, so then I do I focus? Zoom in, focus, zoom out, then shutter? Wouldn't zooming mess up the focus a little bit by zooming out? I have seen some really nice full body shots at 200mm with the 70-200! Me want...
by the time you are far enough away to get a full body shot w/50 you should have sufficient DOF to cover small errors, so no matter what gets focused should be close enough.
Do you see the problems on prints or only at 100% on your computer screen?
mh2000 wrote:
by the time you are far enough away to get a full body shot w/50 you should have sufficient DOF to cover small errors, so no matter what gets focused should be close enough.
Do you see the problems on prints or only at 100% on your computer screen?
Well, that's what I thought too! That's how people can take a full body shot at 200mm and everything is still sharp. So maybe my lens is not calibrated correctly? I doubt it, since I have gotten some really nice and sharp photos...
And yes, they look fine when fitted on the XSi's 3" LCD, but even at 50% on a 19" non-wide LCD, you can tell there is misfocus.
Well, I am gonna the 70-200mm f/2.8 IS first, which has USM, so I should get better focus with that... I hope...