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08-26-2010, 10:54 PM   #16
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QuoteOriginally posted by Nesster Quote
I think of a narrow histogram as analogous to compression in music: it sounds louder though there actually is less dynamic range (defined as the difference in dB between the loudest and quietest parts of the music)
I like this analogy. In fact I actually measured and posted this once, specifically the compression of the histogram between vreyscale 0 and 255 as a function of F-stop for noel monimum and maximum contrast settings

08-26-2010, 10:57 PM   #17
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QuoteOriginally posted by bimjo Quote
Easily proved with a zoom lens. Longer focal length will have a compressed histogram, unless you're shooting just sky.

Focal length has the same effect on your light meter as well.
It's much easier to prove with the op's original shots. Just use a program that allows for a histogram on the selection tool like PSP from corel. Take a selection on an object in both shots and compare the histogram for only the selection as opposed to the whole frame
08-27-2010, 09:08 AM   #18
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FWIW, compression in music is indeed like a narrow histogram, but a histogram could be narrow and be dark overall or bright overall (depending on if the data is concentrated on the left or right of the histogram). The same is actually true in music - you can compress and get a recording that is quiet overall or compress and get music that is loud overall. But given that the *reason* for compressing in music is usually to get things loud overall most compression algorithms include an automatic "normalization", so the result is essentially pushed all the way to the right (insert obvious ETTR analogy here...)
08-27-2010, 10:38 PM   #19
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When I read the OP, my immediate thought was that the Tak was significantly lower contrast than the other lenses (which is possible: most of my vintage lenses have inferior contrast - and colours - compared to my modern Pentax lenses).

However, then it ocurred to me that the lenses had widely differing focal lengths - and therefore fields of view. I think all that is happening is that the Tak is covering a fraction of the subject that's covered by the other lenses. So, there will likely be less variation in luminosity across the FOV.

So, don't panic - it's normal!


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