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Old Nov 20, 2006, 9:40 PM   #1
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I have been having consistency problems (read operator problems) between images, I have burned through about 800 images so far on my new K100D. This weekend I went with my wife to a guinea pig show. There was also a dog and horse show going on at the same time. While wondering around I took about 100 short. This one comparison is probably the best to illulstrate the question.

Here are the specifics on each of the images - DA 50-200 Pentax lens

Focal length 200mm 200mm
Shutter 1/500s 1/750s each with spot metering
Ap f8.0 f11
Exp mode Auto Auto
White Bal Auto Auto

.... also each of these frames are about 3 seconds apart

[img]file:///C:/Documents%20and%20Settings/Gordon/Desktop/horse%201.jpg[/img]



[img]file:///C:/Documents%20and%20Settings/Gordon/Desktop/horse%202.jpg[/img]


Essentially the same short, same light, same focal length, program mode, etc - however different exposure and appature

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Old Nov 20, 2006, 9:48 PM   #2
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Sorry about the sizing, each of the above are just resampled through Irfanview. I have other examples where I have several and one is pretty good with the others very washed out - way overexposed (usually in the automatic program mode).

While at the horse show - I did not worry about depth of field, I just left went fully automatic and was practicing framing things in motion.

I expect differences between frames, but not the large amount of differences. I choose the ones above because they were essentially the same shot and did not expect the wide difference in exposure time and f stop.
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Old Nov 20, 2006, 10:00 PM   #3
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I can't see any images so can't say exactly what happened but here's what I guess is the problem: Spot Metering.

Moving the camera slightly could shift the metering area (just a small spot in the centre) to a different part of your object resulting in a different meter result.

A light object would give different results when compared to a dark object when in the same lighting conditions.

As I said before, it's just a guess as I can't see any pics.
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Old Nov 20, 2006, 10:00 PM   #4
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Here is another comparison

the DA 50-200 lens

Image 1 160mm 1/750s f9.5 spot iso 200
Image 2 160mm 1/500s f8 spot iso 200

and the images are a second apart in time. Note the blown out background.

I have just recently switched to spot rather than center weighting. I am beginning to wonder if this is the problem with the blown out images....

[img]file:///C:/Documents%20and%20Settings/Gordon/Desktop/horse%203.jpg[/img]




[img]file:///C:/Documents%20and%20Settings/Gordon/Desktop/horse%204.jpg[/img]

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Old Nov 20, 2006, 10:04 PM   #5
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I just noticed your images are linked from your hard drive and that's why they are not showing up.
You'll either need to upload them one at a time using the 'Attachment' option at the bottom of the 'post reply' window or...

Upload your images to a free hosting site (eg www.imageshack.us) and then post the images in the same way you did before, but using the URL you'll get from Imageshack.
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Old Nov 20, 2006, 10:06 PM   #6
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Thanks - I upload them for you all. Too hard of a day at the office - I thought I would take a break and relax with the images........
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Old Nov 20, 2006, 10:13 PM   #7
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I don't know how this will turn out - but .....

http://img218.imageshack.us/my.php?image=horse1zm1.jpg repaired again & again
http://img209.imageshack.us/my.php?image=horse2xq8.jpg

http://img297.imageshack.us/my.php?image=horse3vc9.jpg
http://img300.imageshack.us/my.php?image=horse4gg5.jpg


I have no idea why the first and third images will not load?????

.....

thinking it through - it must be the spot metering - I think I will go back to the 11 segment averaging






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Old Nov 20, 2006, 10:57 PM   #8
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I'd be be very interested to hear others comments on how to overcome the the exposure problems like the one on number 4. I may be wrong but I think on that shot if you spot metered on the "dark" colored horse that would blow the background to get the detail in the horse that you did.If you were close enough perhaps the multiseqmented metering and fill flash would have worked. I'm also interested in shooting horseshows and rodeo and this is a common problem with shooting dark colored hoses.
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Old Nov 20, 2006, 10:59 PM   #9
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"dark colored hoses."

Sorry bout the typo on my last. Make that dark colored "horses"

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Old Nov 20, 2006, 11:03 PM   #10
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Not sure why those 2 images aren't showing up....

But looking at the other 2 I'm pretty sure it is spot metering.

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