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Soft Focus in product shots with Nikon D200

spitfire72

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I am pretty sure this an issue with my use of the camera and not the lens (I read the lenses are not digital post). I am an experienced photographer but haven't gotten my complete groove with digital, at least in the studio. I also used to have better eyes, so I was a great manual focusser. Now, I prefer to rely on auto focus. But no matter what level of functionality I use with the auto focus, I can't get super sharp photos. I have to sharpen to the gills in post to get clarity in the type on a label but don't like what that does to the overall image. And it looks to me as if the original image is just soft in places. I'm shooting at f14/100 iso100 with strobes of course. I'm wondering it it's actually a limitation of the medium, operator error, or a problem with my camera. Here is a link to two images: Dropbox - Photos - Simplify your life one a jpg of the untouched file, one which has been sharpened and BG removed (and composited with another file - just look at the label). Once I shrink even the sharpened one down, the words Basilsk and Russian River become blurry. Any advice greatly appreciated.
 
I can see the weave of the paper label on the wine bottle, but also some color aberration too. It might be your choice of aperture. The focus looks fine.
 
Then my question is about depth of field. How am I losing focus at f14 when the lefthand side is only a curve, millimeters from the front of the bottle which is in focus?
 
What lens are you using? The amount of CA present doesn't bode well for the quality of the glass, and that could in fact be one of your limits.

Shooting at 14 is going to reduce sharpness to begin with... have you tried any at 7.1 / 8?
 
There's a few things at play here:

Firstly the D200 has an APS-C sized sensor. The smaller sensor leads to a larger aperture where diffraction effects start becoming visibly apparent. As such you'll find the "peak" sharpness aperture moves down a full stop or so from a body with a 35mm sensor. While lenses may perform optimally at f/11 or so on a D700, they perform optimally at f/8 on a D200. At the point where diffraction becomes relevant decreasing the size of the aperture will reduce sharpness, so f/14 is probably too small of an aperture to be playing with.
One of the ways around this for incredible depth of field is to use "focus stacking" techniques where two pictures with slightly different focus points are combined to artificially increase the depth of field. Works well for still product shots.

The second issue that you may not realise about digital is that the sensor on nearly all cameras incorporate a beyer pattern. A CCD or CMOS sensor are only capable of recording shades of grey, however your 10 megapixel camera actually has 2.5million blue, 2.5million red and 5million green pixels laid out in the pattern:
RGBGRGBG
GBGRGBGR
BGRGBGRG
GRGBGRGB

Beyer interpolation then makes a final colour 10 megapixel image based on not 1 data point, but several. As such it is never possible to get a sharp pixel, and with most algorithms a single pixel light source will actually appear as a cross. What this means is that sharpening a digital picture is NOT optional. It's compulsory and the only question is how much do you sharpen. Your camera JPEGs should produce sharpened images out of the box (though the D200 is quite poor with it's sharpening). If you shoot RAW, you MUST turn on sharpening in post processing.

Finally it's a question of acutance, or how sharp something appears. If you're losing acutance when down-sampling then question the method of down-sampling. Any image that is smaller than an original should appear sharper, and given the size of the images you linked to you could have taken it with a kodak disposable and it should appear perfectly sharp if done properly.
 

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