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06/24/2012 06:54:32 PM · #26 |
Originally posted by MelonMusketeer:
It sounds like the lens is focusing the way it was designed. Maybe you were just so excited to get it yesterday that your heavy breathing was fogging the lens? |
Somethimes I over think and get totaly corn-Fuzed  |
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06/24/2012 08:22:04 PM · #27 |
Originally posted by littlemav:
I do have several where I did not change the focus distance, with the same result... I am running off to find a yard stick..... OH to make this even better... My friend just bought the same lense (she has a Cannon) and she is having the same problem... |
Most lenses aren't at their best wide open, but still you should be able to get something reasonable sharp and in focus. But if you're both shooting Sigma 70-200 f2.8s, for Nikon and Canon respectively...did you buy them from the same source? New or used? Just curious. |
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06/25/2012 11:56:15 AM · #28 |
Wellll Thanks to everyones help and suggestions, I think I"ve got this problem figured out... shooting from 4 ft (or max closeness of this lense) I zoomed into 200mm and aimed @ my hummingbird feeder edge. It seems that my hands don't just shake, they Jerk when I'm trying to hit a itty bitty spot. OS don't help that if your aim jerked 2" off I B thinkin Tripod when ever I'm shooting wide or wideish open....
Here is my last test shot, I did several @ 1250 hand held, most were in focus, but the ones that weren't had NO focal point, showing me that I missed my mark totaly. On the tripod 6 shots looked just like this one, and I think this is perfect.... for (f2.8, 4 ft, 200mm)
Susan, No I didn't shoot the canon, and they weren't bought at the same place and I totaly know what her problem was now... Both New Lenses... |
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06/25/2012 12:04:28 PM · #29 |
Ok now that's what this lens does at f/2.8 :) and look at the BG!
The lens is a Full Frame lens (non-DX) meaning that the effective FL is 1.5x that of a "similar" DX lens on your D90 DX sensor.
This means that when you are at 70mm it is effectively 105mm and when at 200mm it is 300mm f/2.8 :)
The inverse Law tells you that you MUST be at an equivalent of at least the same s/s as the FL or you will get blur, more so without the OS.
I shoot this lens hand held Aperture priority at more than the equivalent of the FL. So if at 200mm (300mm) I am at 1/400th or more. I prefer to be around 1/800th. Keep the s/s in mind when shooting hand held. On a tripod; no great shakes pardon the pun :) Also that's where OS II is for. OS I is for you shaking, OS II is for what ever you are standing on shaking i.e. a boat, a moving platform, on the back of a flat bed. OS should be off when tripod mounted.
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06/25/2012 04:35:34 PM · #30 |
Originally posted by HarveyG:
Ok now that's what this lens does at f/2.8 :) and look at the BG!
The lens is a Full Frame lens (non-DX) meaning that the effective FL is 1.5x that of a "similar" DX lens on your D90 DX sensor.
This means that when you are at 70mm it is effectively 105mm and when at 200mm it is 300mm f/2.8 :)
The inverse Law tells you that you MUST be at an equivalent of at least the same s/s as the FL or you will get blur, more so without the OS.
I shoot this lens hand held Aperture priority at more than the equivalent of the FL. So if at 200mm (300mm) I am at 1/400th or more. I prefer to be around 1/800th. Keep the s/s in mind when shooting hand held. On a tripod; no great shakes pardon the pun :) Also that's where OS II is for. OS I is for you shaking, OS II is for what ever you are standing on shaking i.e. a boat, a moving platform, on the back of a flat bed. OS should be off when tripod mounted. |
What he said....couldn't put it any better, good job Harvey! :-) |
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06/25/2012 04:51:57 PM · #31 |
Make sure you aren't "stabbing" with your finger when you trigger the shutter. It should be a nice smooth roll of the finger. Stabbing will kill many of your shots.
Also, this is my favorite focus chart.
Keep a steady hand and you should be able to shoot pretty slow, and practicing the various techniques helps a ton. I've shot at 1/160 @ 200 on a crop before and gotten sharp output without stabilization, but it takes practice and attention. Your grip influences this (see Mcnally's Da Grip for one technique) as well as breath control and steady body posture. Also, using your high speed release and getting several shots in a row will aid your chances of nailing focus. Capture 3 images in fast succession. Often 1 or 2 of the 3 will be more blurred, but one will be nice and sharp.
But definitely expect that under such conditions you will have a good deal of blurred shots. Take your time, practice, refine. It gets easier.
ETA: Also, another thought on lenses people find to be "soft" from lensrental.com.
Message edited by author 2012-06-25 16:53:52. |
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06/25/2012 05:12:15 PM · #32 |
Correct Derek. I used to be able to Hand Hold at 1/30s but alas no more...
Another thing is a misconception about "crop factor". The lens' Focal Length remains 70-200mm no matter what body you put it on :)
The resultant image has the "Appearance" of what a 105-300mm would have done on a DX body.
//mansurovs.com/lens-zoom-on-dx-15-crop-factor-cameras |
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06/25/2012 06:43:53 PM · #33 |
Originally posted by HarveyG:
Another thing is a misconception about "crop factor". The lens' Focal Length remains 70-200mm no matter what body you put it on :) |
This is true, but in the context of this discussion the "cropped focal length" is relevant. Why? Because the amount of stability required is measured in terms of angular variation as a percentage of angular coverage. If you're shooting a 10-degree field of view and your "shake" causes the point-of-aim to deviate by a single degree during exposure, that's a very significant 10% "shake" and the image will be useless. If you're shooting an extreme wide angle of, say, 100 degrees and you get the same amount of angular deviation, that's now 1% and it is a LOT less noticeable.
Incidentally, the same reasoning applies if you're shooting FF but end up cropping. Whatever is the angular coverage (effective FF focal length) of the final image determines how fast the shutter speed has to be to allow a chance of critical sharpness. So, a 200mm lens on a FF camera, that's nominally 1/200 or faster for hand-holding. Same lens on a cropped-sensor camera (1.6x) OR cropped from the FF shot, that nominally requires 1/320 or faster for sharpness.
Another factor is the size of the print to be made; critical sharpness becomes more and more necessary as the final image size gets larger and larger. Images destined only for web display are MUCH more tolerant of focus issues than images destined for 20x30 prints. We've all seen thumbnails that looked sharp until we open the shot in Photoshop and the flaws are glaringly obvious, right?
Message edited by author 2012-06-25 18:44:17.
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06/25/2012 07:10:06 PM · #34 |
This is true, but in the context of this discussion the "cropped focal length" is relevant. Why? Because the amount of stability required is measured in terms of angular variation as a percentage of angular coverage. If you're shooting a 10-degree field of view and your "shake" causes the point-of-aim to deviate by a single degree during exposure, that's a very significant 10% "shake" and the image will be useless. If you're shooting an extreme wide angle of, say, 100 degrees and you get the same amount of angular deviation, that's now 1% and it is a LOT less noticeable. .... That explains a lot of stuff, I'd never thought of that but seeing it in print I thought well duhhh yeah.
All such wonderful advise on this thread! Funny thing about my hand "Quake" I sat here at the desk the last night zoomed across the room @ 200mm on a word on a book, and with the OS on hand shot 1/15 th (@f2.8) and it was sharp.... I wonder why sitting makes my hand steadier than standing.. AND.... when I shoot a gun, I am a dead shot. Just thought of something, I shot cowboy mounted shooting for a LONG time, you don't have time to set n think point the gun and shoot, and I still shoot my pistols that way, raise to the target and shoot with out thinking. so hummm ya think it's a mental thing??? Oh wait you'd have to have a brain to have a mental issue... (snicker)
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06/25/2012 07:26:01 PM · #35 |
| My advise spend a few bucks and get a reputable camera repair shop check and set the calibration of this lens worth diong and worth every penny . |
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06/25/2012 07:49:00 PM · #36 |
I have shake days and days when I don't shake so much. I think it's coffee related. There are two "work-around" techniques that I use for hand holding the camera on the jittery days.
The best one is to set the camera for continuous shutter release if I'm shooting on the move. A lot of times the second shot, after I have the shutter button all the way in, and a good grip on the camera will be the sharper one.
The other trick is best when the subject is stationary, and that is to set the self timer to 2 seconds. This gets things started, and I use that time to get more stable.
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