Focusing HAsselblad 180MM CFW

[photojerry]

I used a 180M CFE and tried to focus at infinity . Subject 200 feet

plus from the camera. I was not able to "line up" focusing screen. Am

I doing something wrong or could there be a problem with the

lens??????

Thank You

 

Jerald Rosenfeld

[fotografz]

Hmmm, I wonder if this is like a lot of longer lenses that focus

past infinity to account for temp changes???????

[sergio_ortega6]

Jerald,

 

I'm assuming when you write that you are unable to "line up" the focussing screen that you have the split-image center-spot focussing type of screen, and not the plain ground glass type. Just a few thoughts to help diagnose and understand the situation:

 

Is the focussing screen seated correctly in the body under the folding hood? Or could the plastic screen itself have slipped out of adjustment from its surrounding metal frame? Could the split image spot be damaged?

 

I once failed to correctly seat the screen in the body ledge and was unable to achieve sharp focus of distant objects at the infinity setting on the lens. It took a little head-scratching and trial and error before I figured out the problem.

 

It could be the lens mount, either on the body or the rear of the lens. Does the lens attach as usual? Does it snap in place with authority? Do your other lenses (I assume you have more than just the 180, right?) mount correctly? And do they focus at infinity?

 

Is the body's mirror in the correct position? Could it be sticking it its travel and not returning to the correct position? This could throw off the focus. Do you have more than one body, and does the 180 do this on the other body? If it happens on both bodies, then it's likely a lens problem.

 

Neither the 150 or 250 CF lenses I have focus beyond infinity. The infinity symbols line up and stop right at the focussing witness marks on the lens barrels and go no further. I've used other long lenses that go beyond infinity (to possibly compensate for temp changes, and so on), but not the Hasselblads. So I don't believe this is possible unless the lens is damaged. Does your infinty symbol spin beyond the witness mark?

 

If none of these observations help remedy or isolate the problem, then it could very possibly be a faulty or damaged lens. If that's the case, then it's off to the repairshop.

 

Good luck, Sergio.

[grep_mat]

The simple answer is that "200+ feet" is not infinity. Not even close. Focus on the horizon for this test.

 

By the way, I once ruined a couple of rolls of film at an air show when I mistakenly trusted that the runway (more than 200 feet away, I assure you) was at "infinity" instead of actually focusing my 200mm lens. Never again.

[photojerry]

I have determined that the lens is defective. I believe that he lens has to be re calerbrated . The focusing ring is off by a few millimeters. I determined this by

A. Trying other lenses and they focus at infinity.

B. Insured that the 180MM was seated tight into the camera

C. Checked the focusing screen to insure that itwas seated correctly.

 

Thank you for your responses.

 

Jerald Rosenfeld