(Serious) Focusing Problem

[hooten_baldini]

Hi All.

 

Lately, (the past 5 months) I've been having the darndest time focusing lately.

My last 4 shoots, the majority of my shots have been out of focus. I should

mention that I wear glasses but never shoot with them on. I am nearsighted but

not too bad.

 

I primarily shoot with a 100mm CF and 150 CF on a 503CW with a PM45 and a a12

back. I really like the setup. It produces beautiful images while still allowing

me to handhold. It's my big SLR (no disrespect meant!).

 

At first I thought it was the lenses, which have been rentals. But it when it

continued, I narrowed it down to the body.

 

I just had it serviced at Steve Camera Repair in Culver City. He said that the

mirror and the groundglass where off. He adjusted accordingly and assured me

that it was fixed.

 

I then taped a magazine to a wall in my ally and shot 2 test rolls with the 100

mm and 150mm. I adjusted the diopter (it was slightly off) and shot.

 

Out of the 24 frames, 7 off them were either slightly soft to very soft. I shot

from distances of 5 feet and 10 feet. It was in shade so my fstop's went from 4

- 5.6. I don't think this makes much of a difference as some of the wide open

shots were tack sharp while some of the 5.6 were soft.

 

I have a -1.25 in my left eye, which is the one I use to focus. I've never had

(this much) trouble focusing before.

 

Could it be the back? Occasionally, when I load a roll or unload a roll or even

in the middle of a roll, the back while "pop" as if it is being reset in it's

proper position.

 

Any help would be appreciated. I'd be happy to clarify anything if more info is

needed. Thanks in advance for the advice.

[BrianS1664879711]

I'd suspect that "pop" has something to do with your problem. did Steve service the back too? If not, maybe he should. None of my backs "pop". I, too, have imperfect eyesight but I can focus well with glasses or without glasses -- without glasses takes longer, of course.

[simonpg]

Hootan, it is a fairly complex question with a number of variables. But since it is a recent problem, this might help:

1. when you focus the camera/lens, does it appear to be in focus?

2. if the image appeared sharp to your eye are you sure the trannie is OOF precisely where you focused it (hope you did not focus and recompose for your test)?

3. TRY THIS - remove the PM45, use the WLF and with the magnifier up; tripod mount camera; focus on chart specific spot then use a marking pen and circle on the chart where the exact point of focus is (noting that your eye should see that point as razor sharp); make the exposure

4. if you have 2 backs do the same exercise on a second back to see if the results differ. Use positive film for better examination on a light box.

 

I think the answer will then be obvious: if it LOOKS sharp in the WLF magnifier and the image is soft - I think the back is the issue especially if the lens was previously checked for accuracy along with the mirror etc..

 

Good luck.

[bwbob]

Try putting the camera on a tripod rather than hand holding. At least that will eliminate motion as the problem rather than focus

[wai_leong_lee]

-1.25 is not a lot. I don't think you need to use a diopter per se, especially in bright daylight.

 

What you could do is set it up on a tripod, using only the ground glass and a magnifying loupe, focus and check the focus distance using a tape measure from the film plane to the target. If the distances do not agree, set them to agree and see what the image looks like under the ground glass. If it's clear that the image is not in focus on the ground glass when you have confirmed the distance with a tape measure, then it's likely the lens or body.

 

If however the distances agree, but the negs still turn out soft, then it could be film flatness or film back issues.

[james_symington1]

Hootan,

 

Another forum member Gary Ferguson recently mentioned that he frequently finds it necessary to re-seat his focussing screen in his Hasselblads and that this made a substantial difference to focussing accuracy (although he does use a digital back which will show up faults much more easily). Just a suggestion.

[david_henderson]

I must say that my first port of call on this type of problem is also the focussing screen- not least because its so easy to fix if its the culprit.

 

I'd then be inclined to run a series of test shots at known distances corresponding to distance settings on the lenses -ie set the lens to 5 feet, shoot on a tripod from exactly 5 feet whether it looks in focus or not. I would also check and note whether the subject looks sharp when you have it focussed at the the right distance. Repeat at 10 feet, 20 feet 50 feet and so on. If these shots are all sharp then there is something the matter with the way you're focussing it or holding it. If they aren't, then you have a problem with lenses (2!!!) or with the way the film is being held in the back. I think a problem with 2 lenses is unlikely, and that if there were a problem with the back I think it would be more likely to have variable sharpness over the frame than a uniform unsharpness. However I think the odds are in favour of a focus or camera movement issue, and a focus problem could be you, or could be something awry on the path between your eye and the lens despite you recent repair.

[ulrik]

Are you using a split image type screen? This should ensure consistent focussing and eleminate one variable in this complex equation. To replace the popping magazine seems to be the next logical step.

 

Ulrik

[russ_britt3]

Do you know someone with a groundglass for the hassey back? You could put this on and check the camera ground glass againt the rear ground glass and rule out the mirror and camera body if they checked the same. Ground glass units sell on e-bay very cheap sometimes...I think I bought one for under $100 for my superwide.

[cameron_ertman]

Since no one has mentioned it yet, are you remembering to put the film under the metal tab on the film insert when loading?

[hooten_baldini]

Hi Guys.

 

Thanks for all the advice. I didn't use a tripod to shoot the test's so I think that is the next step.

 

As for the back, I have a sneaking suspicion that this could be the problem.

 

I do not put the film thru the small silver tab inside the back. I'm going to start now (only after 5 years. :O)

 

I'm doing a shoot this sunday and will report back with the results. Wish me luck and good focus!

 

Hootan

[simonpg]

Hootan, to be sure about sharpness you MUST use a tripod and mirror pre-release.

 

But I am also concerned that you do not "put the film through the silver tab..."! While I do not know HOW important that tab is to film flatness - IT IS VIP to load the backs exactly like the manufacturer instructs.

 

That tab certainly holds the film in place for inserting the magazine into the back and it is released when you lock the back closed, so it is possible that your film does not seat properly.

 

So do a test again using a tripod and loading the film magazine correctly before you jump to conclusions. However, like I posted earlier I suspect your back / magazine needs adjustment of the film pressure plate. But you must use the gear properly before you look for faults.

 

By the way how old is the film magazine / back; when did they last get a service; did you buy it new....? Film backs are sophisticated devices and need servicing periodically to ensure their optimal performance.

[hooten_baldini]

Hi Simon. I just shot 4 rolls today and made sure to run the film thru the silver tab. Wow, what a difference.

 

When cranking the film to the first frame, it was smoooooth. Everything sounded like it was much better.

 

I shot polaroids and everything looked nice and sharp (well, as sharp as a poloaroid can. :O)

 

I'll get the film back tuesday so I'll report the results.

 

As for the back, it was new when I got it. It's the newest style A12. It's in relatively good shape. I had a service technician look at it about 3 months ago. He concluded that one edge needs to be filed down slightly. He performed that for me.

 

Not once did the back "pop" today so I take that as a good sign.

 

Thanks again and i'll keep you posted...

 

Hootan

[simonpg]

I'm glad I could help with a posible solution - when I saw how you were loading the magazine and back I shuddered thinking how that film must have been badly seated.... always follow the manufacturer's instructions since every little feature on a Hassey has a function.

 

If you don't have it, BUY the Ernst Wildi book "Hasselblad Manual" - it is a must have.

 

Good luck.

[cameron_ertman]

Happy to help regarding the tab. The colder the outdoor temp., the more the tab helps with film flatness and the smooth operation of the back. Keep us posted about the results when you get your film back.

[hooten_baldini]

Hi Guys.

 

I was anxious to see the results of the shoot so I picked up the film early.

 

Good news and bad news. The good news is that some of the shots are tack sharp. Dead on.

 

The bad news is that the majority of the shots are out of focus.

 

I shot handheld primarily with the 100mm CF and 150mm CF. The same back that has been making that "pop" sound. This time, I made sure to run the film thru the silver tab before I loaded it into the back.

 

I took precaution not to shoot wide open. I used 400 rated film to give me the room to use bigger fstops.

 

I've posted a couple of examples of the shots. Really strange but it seems that parts of the shot are in focus and parts are out.

 

If the film plane is off balanced, then this would be a logical explanation right?

 

I don't know what to do. I'm going back to Steve, the technician that serviced the body and show him the results. When I bought the lenses, I had a different technician put them into a device that checks focus and he said they were fine. He even tested the shutter speeds and they passed beautifully.

 

Any help would be appreciated. I think the next step is to rent a different back and shoot a test roll with it. See what the results will be.

 

In the picture I posted, notice that the details of her dress are but her face is soft. This is a rough scan from the proofsheet but the negs are the same. Sharp details on the dress, soft on the face. This was shot with the 100mm, but an entire roll shot with the 150mm at f8 has the same problem: Selective focus!

 

Let me know what you think. Thanks Guys...<div></div>

[hooten_baldini]

here's a shot from the 150mm. Notice that her lips are in focus but her eyes are not.<div></div>

[simonpg]

Hootan, I suggest you take the body, one of the lenses and viewfinder etc in to an experienced H technician - explain the problem and let him fix it.

 

I still suspect that the back is the problem - I suspect that your past failure to load the film on the magazine correctly may have been part or all of the reason for the pressure plate now being out.

 

Remember it is an SLR so when you focus, WYSIWYG generally, so what looks sharp should be sharp on the film. So IMHO the film back seems to be the issue. It seems to have improved since you load the film correctly this time, but is still out.

 

Did you take my suggestion and try a second film back (say a borrowed one known to be spot on) during your test? That would certainly show up a film back fault.

 

Don't just take in the back, let the tech check it with the whole setup to be sure. These things need experienced technicians and tools to get right. When fixed it should stay that way for decades.

 

By the way scans of film rarely allow accurate technical analysis - in this case sharpness is not well seen in scans since scans like digi-cams do not produce a very sharp image and need post-processing. So don't drive yourself mad and let a good tech deal with it IMHO.