#47. "RE: Soft Focus - How About A Standardized Test ?" In response to In response to 0 Wed 06-Feb-13 03:45 AM by agitater
>What we need is one (or a team of) the gurus' to come up with >a D7000 standardized soft focus test. > >Select a lens we probably have to start. 50mm f1.8. If you >ain't got it, $125 is not too much investment to participate. >You need that lens anyway. Or borrow one! > >Tell us the camera settings. >Tell us the tripod height and subject distance. Include the >distance to the background. >Detail the lighting, hopefully flash to minimize variables. >Select a subject and background we all have. > >Be specific. I am a novice. I would love to post my pic to be >compared to other D7000s'.
Despite any other comments with respect to the need for a broader base of photography knowledge before delving into the subject of focus testing, the proposal seems reasonable on its face. The problem is, commercial focus testing products already exist that any photographer can purchase and set up at home. The products contain extensive kits, setup instructions and recommendations.
The 'gotcha' with such products is that no setup shortcuts are permissible. If all of the main variables addressed in the setup instructions and recommendations aren't fully and accurately adjusted as required, the testing will not produce valid results. Frankly, the vast majority of home-devised, commercial DIY, and field test designs are so full of technical holes that the photographers engaged in the effort might as well not bother. It's also just as important to note that the odds against getting fully usable results from such flawed setups often put them completely out of reach even by pure luck. That such setups occassionally do produce results usable enough to warrant an AF fine tune calibration tweak is not a reason to bother with it. Chances are your results will be unreliable.
Anybody who spends time performing AF fine tune calibration on a zoom lens is going to end up either limiting the usability of part of the focal range, or in the case of a combination of bad technique and bad exposure settings choices is essntially trying to overcome those mistakes by attempting to calibrate them away.
Sure as anything there are camera and lens combinations which conspire to produce soft images. They are rare. Those camera and lens combinations might benefit from an AF fine tune tweak. But always refine knowledge of the camera and the techniques being used, before fixing something that too often will prove not to be broken.
>Please help me understand soft focus. I feel this would be a >VERY popular test, those knowledgeable in the subject could be >very helpful to us lost sheep!
If you really want to delve deeply into the subject of absolute focus accuracy, first learn the basics of aperture (and how it affects depth of field), shutter speed (and why faster shutters speeds tend to produce sharper photos, ISO (and why lower ISO settings produce lower digital noise and hence photos with more finely rendered detail, white balance (and why doing a custom white balance when confronted with confusing lighting helps the camera sensor capture color more accurately and therefore gives your eyes a more accurate rendering of the subject). Add to that knowledge the practice of steady handheld shooting technique, and you'll end up getting the best out of the camera as it has been delivered to you from the factory. If you're still not satisfied with sharpness after that, you have a baseline from which to much more confidently and accurately perform focus testing.
For now though, I don't see anything wrong with your sample shot except f/1.8 which provided such a paper thin depth of field that only a tiny band is in focus.
If I've gone too far with the comments in this post, I apologize.