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12-27-2006, 01:47 PM   #1
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SMC 300 f/4 problem - me or the lens?

Hey gang,

I just got an SMC 300mm f/4 (the old K version) last week and took a few test shots. Besides my inability to properly focus, I noticed some color noise/chromatic aberration/color fringing/whatever in the pictures. I don't think it should be there, and I've never noticed it in my other lenses.

My question is what caused it? Did I screw something up? Is this a limit of the lens? Is it damaged? The lens appears to be in excellent condition and was rated as "EX" (excellent) by KEH where I purchased it. Opinions are welcome.

All shots were at or around f/16. On a couple of the shots, I sharpened one step in PPL3, but others have no post processing other than cropping. Any comments or suggestions?

Here's one taken through the window of my office. Seems sharp enough and no real qualms with the picture.


This one shows the CA/noise pretty well. The pelican is the focus of the shot, but the background shows the problems. I think this was the shot that was sharpened one step in PPL3.


This one had no post processing except for cropping. It really shows the noise problem. Look at the person's white shirt in the bottom right of the photo.


This is probably the best shot from the set but still nothing to write home about.


What's happening here?

12-27-2006, 04:34 PM   #2
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#1 and #4 are great but #2 and #3 may just be a camera setting or a bad memory card. I have never gotten anything like those with my k300 as I posted to you at the 'other' place. Were they all taken at the same time with the same memory card?
12-27-2006, 04:52 PM   #3
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Russ, I've never seen anything like #2 and #3 with my K300 (bought new in 1979), but I don't use it much. My arm wears out too soon!

Jerry
12-27-2006, 05:09 PM   #4
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Hot spots appear to bring out the CA. Noticed on the vehicle where the streetlight/sun was reflecting in 3 spots on the rear hatch CA.

Baffles me as to why they show up so pronounced in the pelican shots though. I would suspect a defective lense.

You might want to work up a known hotspot photo session off of a reflection and shoot at a number of f stops to see if it is throughout the lense f stop range. The higher the contrast between two objects, theoretically, the higher the CA. Even if you blew out some of the photos, it could give you good info on the lense.

12-27-2006, 07:31 PM   #5
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I thought the ideal optimal shutter speed is usually 2 stops above the designated lens aperture wide open. Shooting images well beyond that aperture is going to cause difractions and softening of images.

CA is common in highlights or strong reflections with FA lens series. I am no expert in this as Joele told me all about this.

Maybe try f5.6 or f8 to do the shots instead.
12-27-2006, 08:41 PM   #6
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QuoteOriginally posted by wjwncpro Quote
#1 and #4 are great but #2 and #3 may just be a camera setting or a bad memory card. I have never gotten anything like those with my k300 as I posted to you at the 'other' place. Were they all taken at the same time with the same memory card?
All were taken on the same day with the same memory card. #1 was taken and hour or two before the others. #2, 3 and 4 were all taken at the same time. I'm wondering if SR while tracking a bird may have something to do with it. I need to do some more controlled tests. Funny thing is that I never worry about turning off SR with any of my other lenses and I've never seen results like these.
12-27-2006, 08:44 PM   #7
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Do you have any 3D glasses around, maybe its the new 3D effect I've hearing about!!!
12-27-2006, 08:48 PM   #8
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QuoteOriginally posted by roentarre Quote
I thought the ideal optimal shutter speed is usually 2 stops above the designated lens aperture wide open. Shooting images well beyond that aperture is going to cause difractions and softening of images.

CA is common in highlights or strong reflections with FA lens series. I am no expert in this as Joele told me all about this.

Maybe try f5.6 or f8 to do the shots instead.

Thanks for the suggestions. I know I'm not good with setting exposures, and I forget how to meter since I don't use manual lenses that often. I noticed that the shutter speed was very high, though (around 1/2500 or faster), so opening it up much more seems like it would have over exposed.

Sounds like there's enough discussion that it very well could have been user error. I need to take it out with a tripod and try a variety of controlled tests. Maybe I'm just an AF kinda guy.

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