Question/Help about soft focus of a subject

[ralballer]

Hi Everyone,

Need your expertise. I'd like to know why is there soft focus on the right side of this helmet (I have made an inset of the detail):




I have two flash units, one on each side, and the subject is about three feet away from the background. I also tried putting one light behind trying to use it as a rim light with the same results.

I am using a D7000

Thanks!

 

[dxqcanada2]

I think this is more about reflection (of the background off of the helmet) than focus. Looks like the reflection of the white background is causing the appearance of out of focus.

 

[KmH]

The EXIF data shows you used f/32. Investigate how the optical property known as diffraction softens overall focus when small lens apertures are used.

F/32 also makes your flash units work a lot harder than they need to.

 

[Derrel]

Even at f/32, on an object the size of that helmet, at THAT close of a shooting distance, there probably is NOT, I repeat, is NOT enough depth of field to pull the entire helmet into perfectly sharp focus. Well over 30 years of photography experience tells me that, even with my 60mm macro at f/32, I can not get enough depth of field to render a motorcycle helmet in perfect focus from close range like that---the distance is simply too short!!!

But--is that really a problem? I don't think so! What's critical is to render the chin-guard area of the helmet sharp; the human brain readily accepts a slight loss of focus at the back edge of subjects, but really prefers to see the closest object (usually the tip of the human nose) in GOOD focus. The way the helmet is positioned, with the chin-guard projecting forward of the main part of the helmet, means that with a camera that has a lens and film back that can NOT be angled (like a studio view camera with front standard swing and rear swing), or lacking something like say a 45mm or 85mm tilt-and-shift lens, the depth of field's distribution is GOING TO MISS the back edge of the helmet by a SMALL amount...

I don't think a slight bit of softness at the back edge of the helmet is a deal-breaker. Anyway--it's hard to see the problem with your sample's relatively small on-screen size. As KmH alluded to earlier, diffraction softens images at apertures smaller than f/11 with many cameras, yet still on a simple, large, rather crude subject like a helmet with a large, coarse design on it, Unsharp Masking can easily re-create the impression of sharpness enough to do the job...it is not like you are photographing rare stamps with micro-detail in their engraving, you know what I mean???

 

[ralballer]

I will reshoot at a lower F stop and see the results, but everything points to diffraction. I will also check for reflection from the background.

Thanks all for your help.

 

[KmH]

There is no need to bold the text.