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06-07-2009, 01:27 AM   #1
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K100 Super Manual Lens Yellow Tint/Overexposed???

I am using an older Vivitar 70-210 f4.5-15.6 Macro 1:4 manual lens on my K100D Super and it seems to put a yellow tint, or an overexposed look to the pics. I was also using a polarizer on the below pics.
I have tried various shutter speeds and f-stops and while there is a subtle change they still come out with that look.
If I increase shutter speed and lower the f-stop, I get the same yellow tint, and the picture gets darker - See the Half Dome pic
On Macro I get rich color, like I was expecting



So any ideas as to why the yellow tint/Overexposure look?

Here are the pics with the settings:

ISO is set at 200, and WB is set to auto for all pics

Shutter Speed 1/125 F-stop -16


Shutter Speed 1/180 F-stop -16


Shutter Speed 1/180 F-stop -14


Shutter Speed 1/180 F-stop -4.5


When I go to Macro, I get this
Shutter speed 1/350 F-stop - 8


Shutter speed 1/125 F-stop - 16


If I go to the Kit lens and do everything as Auto Stupid - an affectionate term for Auto Pict I get decent color and exposure.


06-07-2009, 03:09 AM   #2
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Lens with low contrast

I do not think it is overexposure, but rather a lens which gives low contrast (perhaps due to bad coating, or lack thereof). When I copied the first picture, there were no clipping in the histogram, but it did not extend towards the "dark side", giving a "washed out look" to the picture.

It can partly be "saved" though by adjusting the levels so that the histogram fill the complete range.

A quick try (including removing colour cast somewhat, which could also be due to coating)

Best regards,
Haakan

Last edited by Haakan; 12-28-2010 at 10:12 AM.
06-07-2009, 03:17 AM   #3
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Haakan, I think has it right. It's a por quality, low contrast lens. There may also be some haze on one of the glass elements that you should look at closely. If so, toss the lens. Nothing much you can do to make a poor lens look good.
06-07-2009, 07:05 PM   #4
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Well, looks like I chock this one up to a lens gone bad..... I experimented, just as a final test and all the pics came out with a subtle yellow tint to them, some less than others.
Thanks, looks like I am on the prowl for a new macro lens.


Last edited by Grzldvt; 06-07-2009 at 09:09 PM.
06-07-2009, 07:30 PM   #5
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Threads about lenses go in the Lens Discussion forum.


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06-07-2009, 08:34 PM   #6
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I have a Vivitar Series 1 28-105mm zoom, made by Cosina, that adds a yellowish tint to images. It's not quite as dramatic as your examples. I am pretty sure that on my lens it is just a lens characteristic. Your lens serial number may reveal its manufacturer.

Your example shots might have lower contrast simply because you were shooting through atmospheric haze. That would explain why macro shots look better. It looks like your kit lens example was the same subject as one of the Vivitar images. If it was at the same time, that theory doesn't work.

Some lenses can lose contrast due to flare. The kit lens almost certainly rejects flare better than this Vivitar, which might be the difference in your samples. A lens element with oil, fungus or some other issue will make this much worse.
06-07-2009, 10:39 PM   #7
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The Kit lens pic was taken within 30 minutes of the 70-210 pics. I took some more shots today using the macro and they still had a very, very subtle yellow tint to them. So, something is deteriorating over time. I figured I had nothing to lose and took the lens apart, I did see some "stuff" on the glass, so I cleaned up the lenses, put it back together, and took some shots. Interesting, with a flash seemed to turn out almost OK, but the rest in very bright white light, still had the yellow tint to them.
Not sure why this lens had a deterioration, but it has served me well.
It has reached the typical looseness and will slide on me if I am pointing it down, so moving on to another lens is not all that bad.
06-07-2009, 11:09 PM   #8
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Could your polarizer be the culprit?
Up close, in macro there would likely not be any flare on either the lens or the polarizer. But the landsacapes are a different kettle of fish.

Mickey

06-09-2009, 05:13 PM   #9
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I mentioned my Vivitar Series 1 28-105mm f2.8-3.8 VMC zoom made by Cosina. Here is a quick backyard snap at f8. AWB chose 5300K, +22 tint:



Here is pretty much the same snap a minute later, with the Pentax FA 28-105mm, f8 and 37mm. I tried for the same exposure but not quite the same framing, sorry. I also adjusted the white balance to the same numbers as AWB chose for the Vivitar, though for this lens it chose 5750K, +9 tint.



So I think your lens has a similar coating, possibly made by the same company. Even equal white balance doesn't go that far in equalizing the colors.
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