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05/14/2006 01:58:36 PM · #1 |
What is the problem here? I'm doing studio shots with hot lights, F1.8 at 1/200 of a second with the focal point on the eyes in a full body shot...and the eyes are blurry?????? 1/200 and the focal point has blur?????
Is this lens a P.O.S. or is there something I'm missing here??? I'll post some shots but it looks like standard motion blur. At 1/200 the focal point should be sharp as a freakin tack...please help me!
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05/14/2006 02:01:29 PM · #2 |
Is there any other part of the image in focus? There are only two reasons I can think of - either the lens is dirty/faulty, or your subject moved between focusing and shutter actuation - f/1.8 is a damn shallow DoF to play with...
Message edited by author 2006-05-14 18:02:37.
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05/14/2006 02:05:17 PM · #3 |
| If it looks like motion blur, then it's likely something was moving, and it probably wasn't any component of the lens ... |
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05/14/2006 02:06:04 PM · #4 |
Even stopping down to 2.2 or 2.5 will sharpen up that lens. It is soft at 1.8; something understandable when we look at the $75 pricetag. Either buy the 50mm f/1.4 for $400 or stop down if you want sharp.
That's assuming it wasn't user error and the softness really is blur or DOF. |
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05/14/2006 02:06:24 PM · #5 |
| Also, f1.8 under hot lights with 1/200 sounds like a setup for over-exposure to me ... |
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05/14/2006 02:06:25 PM · #6 |
Originally posted by Manic:
f/1.8 is a damn shallow DoF to play with... |
yep!
what's P.O.S.? |
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05/14/2006 02:07:50 PM · #7 |
| I'm not a pro but that doesn't sound right to me. I just bought this lens a week ago and it's very sharp. I haven't noticed anything like what you're describing. |
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05/14/2006 02:07:57 PM · #8 |
Originally posted by biteme:
Originally posted by Manic:
f/1.8 is a damn shallow DoF to play with... |
yep!
what's P.O.S.? |
Piece of Shizzam! A feature usually found only on Nikons, but occasionally a Canon user suffers as well.
Message edited by author 2006-05-14 18:08:41. |
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05/14/2006 02:08:31 PM · #9 |
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05/14/2006 02:21:08 PM · #10 |
ouch. be careful, dr.
lol
Message edited by author 2006-05-14 18:21:21.
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05/14/2006 03:21:42 PM · #11 |
the pictures are not overexposed.
I believe this was an error with the camera. The subjects chest area is in perfect focus...though the DOF should have made the eyes blurry, not a motion blur type movement.
The model was not moving, I would have attributed it to camera shake but not at that shutter speed.
I focused on the eyes and recomposed the picture. I'm guessing one of the following is happening with that lens:
1. the lens is not right.
2. the camera lost the focal point during the recomposition.
3. the camera did not focus right during the initial focusing.
4. camera shake.
I took the same shots with my 85mm 1.8 and the eyes were PERFECT.
Like I said, the chest area is in perfect focus and the eyes are blurred, though I initially focused on the eyes. I can focus and recompose like the back of my hand, there is no user error here and I have 20 shots from a different lens that prove it.
Could it be anything I'm not thinking of?
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05/14/2006 03:26:08 PM · #12 |
Sounds like the AI Servo is refocusing during recomposing.
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05/14/2006 03:26:31 PM · #13 |
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05/14/2006 03:27:32 PM · #14 |
Originally posted by specialk0783:
I focused on the eyes and recomposed the picture. I'm guessing one of the following is happening with that lens:
....Could it be anything I'm not thinking of? |
Moving from the eyes to something else would change the plane of focus and if you are at f1.8 then it's pretty thin. Try picking a focus point where you want and not recompose.
You are closer with a 50 then an 85 which is why you might see it in the 50 and not in the 85.
Might not be the issue but worth a try... |
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05/14/2006 03:30:25 PM · #15 |
I know the 300d is naturally soft because of the algorythems (sp), or something like that.
Could the 350d be the same way?
Also, your 50mm doesn't need to be at a shutter speed of 200. If your on a tripod, 80 is pretty good. Then you can close the iris more for better dof.
Message edited by author 2006-05-14 19:33:13.
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05/14/2006 03:31:34 PM · #16 |
DOF is very shallow at 1.8. the nose can be in focus and the eyes not.
most likley user error (yeah, i don't want to hear that either but it's often teh cause).
could be you moved back 2" and the subect did to - 4" is enough to move out of the optimum DOF at 1.8.
I have similar probs at time when i recompose a shot - not sure why, as in theory it shouldn't matter, but it often does. that one reason you have movable focus points. when i use the focus points the focus is more often correct/accurate.
you can do some controlled testing - perhaps the lens is front focusing? As i stated above, whenever i do controlled testing the equipment is fine...so it's me.
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05/14/2006 04:19:51 PM · #17 |
The simple test is to focus on something, don't recompose, and take the shot with the same settings. If it comes out clear, it was something in the recompose, which happens to the best of us.
I will echo, however, that the DOF at 1.8 is very shallow. I've gotten away from it because it's tough to get a whole face in the DOF. |
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05/14/2006 04:25:30 PM · #18 |
before everyone gets their panties in a ball, lets see an example. i know for a fact the 50mm is a very sharp lens - even on the 300d for that matter...
specialK might be strung out or something...
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05/14/2006 04:37:40 PM · #19 |
Focus/recompose is a really bad technique to use when working with shallow dof. At f1.8, even for a full body shot, you'll still only have just a few cm's of acceptable sharpness.
bazz.
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05/14/2006 04:47:59 PM · #20 |
| If you've ruled out error from focus/recompose (and FWIW I agree that if you can hit it with the 85/1.8 wide open, the 50/1.8 should be a cakewalk), and the plane of focus is repeatably behind the intended point, then the lens/camera combination might be back-focusing. Given the camera seems to focus accurately with the 85/1.8, perhaps the 50/1.8 lens needs calibration. It's unfortunately not that rare for a new lens to be off. |
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05/14/2006 05:09:46 PM · #21 |
Originally posted by specialk0783:
Like I said, the chest area is in perfect focus and the eyes are blurred, though I initially focused on the eyes. I can focus and recompose like the back of my hand, there is no user error here and I have 20 shots from a different lens that prove it.
Could it be anything I'm not thinking of? |
does the subject have a large chest area?
:)
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05/14/2006 05:15:13 PM · #22 |
Originally posted by Gauti:
Originally posted by specialk0783:
Like I said, the chest area is in perfect focus and the eyes are blurred, though I initially focused on the eyes. I can focus and recompose like the back of my hand, there is no user error here and I have 20 shots from a different lens that prove it.
Could it be anything I'm not thinking of? |
does the subject have a large chest area?
:) |
Oh my goodness! Hats off to you, Gauti. Just made my day! (sorry for the hijack) |
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05/14/2006 06:40:34 PM · #23 |
This one is pretty sharp, but I was shooting outside on a sunny day, so wide open was 1/4000. Also, I just like the picture. It's my youngest brother and I think I really got a great shot.
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05/15/2006 06:00:53 AM · #24 |
To ask a dumb question, did you select a focus point or let the camera select one? If you let the camera select the focus point, open the image in zoombrowser and enable the focus point display so you can see where the camera thought it was focusing.
Have you checked the focus on your lens? There are a bunch of focus tests on the web. This one is as good as any //www.focustestchart.com/chart.html (even though its for a Nikon, the chart will work for your camera.) |
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05/15/2006 06:13:53 AM · #25 |
i would suggest he was in ai servo on the shot and the recompose well refocused. difficult to say without geting anything. i hate ai servo. only use if i have to with moving subjects coming at me.
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