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Misadventures of a Digital MF Newbie

fotografz

Well-known member
In my continuing saga of learning mfd, I've run to a dof problem I didn't expect. I thought I'd have to open up a couple of stops to get the same dof as dslr and I understand the shallow dof of longer lenses, but I shot my daughter (test of her wedding dress, etc. in studio in Dec.) with 210mm at f11 and one eye is in focus and the other is not. Here's uncropped, cropped, and each eye.

So question is, is it possible for dof to be that narrow at f11 with 210mm or is there something else happening I can't figure out?
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If you used AF I'd bet that the camera AFed on the veil in front of her face, not her forward eye ... at f/11 shot that close with a 210, the forward eye would be with-in the DOF tolerance but the back one probably not.

How do I suspect this ... because I've done it myself one too many times ... LOL!

When they are wearing a veil I now tend to manually focus.

-Marc
 

David Schneider

New member
I honestly had looked at dof charts before I first used the 210mm, but I think Dustbak hit on my problem. I was closer to subject than I thought, probably at closest focusing distance. If I was back just half an arm's length dof would have been about 50% more and both eyes would have been sharp. I think I looked at dof charts at 10 feet (3m), but not under that. Man, I got the warning about the mfd dof, but I guess I just had to see for myself how paper thin it can really be.

Also explains why I didn't have the same problem at f8 that I did at f11. I was back farther.:eek:
 

David Schneider

New member
Speaking of dof charts, I've always used www.dofmaster.com, but there are no Hasselblad digital cameras there. (Surprised to see Pentax 645D there though.) What camera would give me the closed actual dof field numbers? I'm using H3D2-39.
 

SergeiR

New member
Speaking of dof charts, I've always used www.dofmaster.com, but there are no Hasselblad digital cameras there. (Surprised to see Pentax 645D there though.) What camera would give me the closed actual dof field numbers? I'm using H3D2-39.
Doesnt matter - you can just pick up any 645 camera. DOF isnt really changing with crop factor for same focal lengths, only "scale" is. I mean you still get some wobble b/c 645 is a bit different, but it wont be anything major.

Whats more fun is to select lens.. I just looked at chart this morning and found that RZ's 50mm lenses got two different bloody angles.. ULD version is like 4 degrees wider than non ULD.. despite being "about same" :)
 

Dustbak

Member
DoF charts give so-called 'acceptable sharpness' I also have a strong feeling that the term acceptable sharpness needs to be redefined since we use monitors at 100%.
 
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