vr-pilot
lvl.4
Flight distance : 4668169 ft
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I took many photos with my P3P last October (late summer) in Spain. They ALL were fine.
I took a lot of photos in Germany over autumn/winter time. Many (but not all) of them were SLIGHTLY blurry.
I checked this forum and got to the conclusion:
At temperatures below +20°C the lens to target (sensor) distance tends to get smaller due to material characteristics (alloy) resulting in less sharp pictures. This was also generally the case for me. Using shorter shutter speeds helps reducing blurrs caused by motion/vibration, but the "slightly out of focus" problem remained.
But there also seem(ed) to be camera lots who have a general "factory set flange" problem.
In my case: I thought that using a variable ND filter would be a good idea to easily acquire video friendly shutter speeds (e.g. 1/100s @ 50fps) on every occasion. Unfortunately there were blurry spots on my photos ("objectively" unnoticeable on my videos). These were probably caused by the dual polar filter method itself by rotating one filter from parallel through orthogonal relation to the other fixed filter. I think that medium values close to 45° relative orientation may have caused those blurry spots due to optical ray displacement (change of density/obstruction).
I am not a physicist, but I think the polar grid dimensioning for such small filters/lenses/sensors has to be noticeably smaller than for standard optics. As I said, it nevertheless worked fine for videos.
Now it's getting warm spring time/summer and all my photos are sharp again using "fixed"/"smoked glass" ND filters. This must be the temperatures at which the flange was set factory wise.
After all I am still wondering, why 4K winter videos can be pretty sharp while 12M winter photos are out of focus. And that at fixed focal length and aperture...
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