Focus issues with Rolleiflex 3.5f with Rick Oleson splitscreen

[Analogski]

Hi everyone,
I’m experiencing a consistent focus issue with my Rolleiflex 3.5F and I’m hoping for some insight from other Rollei users or repair techs.

When I focus carefully on a subject (e.g. a person leaning against a bridge railing), the subject ends up slightly out of focus on the negative, while the immediate background (the railing itself) is sharp. This happens consistently and is most noticeable at wider apertures. With the original Rolleiflex focusing screen, I never had this problem.
The camera currently has a Rick Oleson split-image focusing screen installed. Orientation is correct (matte side down, toward the mirror).

According to Rick Oleson employee, it isn't the focusing screen put on the wrong way, but something with the camera. But I doubt it, because it was working fine before.

 

[Dan Daniel]

You can test by putting the camera on tripod (or keep on table in same spot), focusing with one screen and swapping in the other to see if it focuses on the same spot.

Did the old screen have a split?

Splits can be tricky. You can see how head/eye position can change the focus. It could be that the new split requires a different eye position. This can be subtle.

You might also check the microprism doughnut focus on the Oleson, compare to both the original screen and the split section of the Oleson.

 

[Analogski]

You can test by putting the camera on tripod (or keep on table in same spot), focusing with one screen and swapping in the other to see if it focuses on the same spot.

Did the old screen have a split?

Splits can be tricky. You can see how head/eye position can change the focus. It could be that the new split requires a different eye position. This can be subtle.

You might also check the microprism doughnut focus on the Oleson, compare to both the original screen and the split section of the Oleson.

Thanks. But when I focus, the subject I'm focusing in, is perfectly in focus, but on the negatives the subject is slightly out of focus and the direct background is in focus. It drives me crazy. I'll do a test: 6 exposures with one screen and 6 with another. Then I'll know for sure. Too bad I'll have to sacrifice one film roll and pay for the whole development/scanning

 

[Analogski]

And no. The old one doesn't have a splitscreen

 

[RalphLambrecht]

And no. The old one doesn't have a splitscreen

so,why don'tyou stick to the old screen?

 

[OAPOli]

In the 3.5F, the screen drops into place. There can't be any difference in the focusing plane between screens. So I suspect the problem is in the viewing lens which is out of phase with the taking lens. I suggest having the camera checked out.

In other Rolleiflexes, the screen is clipped on the hood from its underside. So slight differences in screen thickness will affect the focus plane.

 

[Analogski]

so,why don'tyou stick to the old screen?

Because I wanted a splitscreen and thought it would also be a bit brighter. But that's not the question

 

[Dali]

If you have issue with Oleson's screen only, then you know the culprit.

Now, is your Oleson screen designed for 75 or 80mm lens?

 

[Kino]

A small square of ground glass placed on the film plane should allow you to compare the viewfinder focus to the focus on the actual film plane.

 

[stan_1]

Hi everyone,
I’m experiencing a consistent focus issue with my Rolleiflex 3.5F and I’m hoping for some insight from other Rollei users or repair techs.

When I focus carefully on a subject (e.g. a person leaning against a bridge railing), the subject ends up slightly out of focus on the negative, while the immediate background (the railing itself) is sharp. This happens consistently and is most noticeable at wider apertures. With the original Rolleiflex focusing screen, I never had this problem.
The camera currently has a Rick Oleson split-image focusing screen installed. Orientation is correct (matte side down, toward the mirror).

According to Rick Oleson employee, it isn't the focusing screen put on the wrong way, but something with the camera. But I doubt it, because it was working fine before.

There is a mirror under the ground glass, you may want to check whether its not displaced. otherwise (if the screen is inserted correctly) it may be that it doesn't have the exact same thickness and that's what's causing a misalignment.

If your camera taking lens focuses correctly at infinity (infinity shots in focus?), you just set the dial on infinity and then you have to adjust the focusing lens so that the focusing screen also focuses to infinity. For this you remove the front plate and screw the focusing lens forward and backward until the split screen correctly aligns for infinity. There are video tutorials on YouTube how to unscrew the front plate of the Rolleiflex 3.5F, though it's not very easy if you haven't done it before. If you want to be exact, a better way would be to have a collimated target for adjustment, though thats a bit more complicated.

If you set the focusing dial to infinity and the shots (the actual negatives) in distance are not in focus, then that's more complicated. You'd have to adjust the taking lens Or the focusing dial.

Edit: another cause of a focusing issue are problems with the pressure plate, maybe set to 220 film instead of 120 or some other issues with the springs etc.

 

[Dan Daniel]

Too bad I'll have to sacrifice one film roll and pay for the whole development/scanning

Stsrt with a simple field test. Camera nailed in one place. Focus with one screen, then swap in the other screen. Has focus position changed? If so, it is a screen problem.

 

[Dali]

Stsrt with a simple field test. Camera nailed in one place. Focus with one screen, then swap in the other screen. Has focus position changed? If so, it is a screen problem.

Analogski wrote: "With the original Rolleiflex focusing screen, I never had this problem.".

Draw your own conclusion...

 

[Dan Daniel]

Analogski wrote: "With the original Rolleiflex focusing screen, I never had this problem.".

Draw your own conclusion...

A problem with split screens is that people move the camera to place the focus point in the center of the screen, then reframe the shot before firing the shutter. With TLRs especially, it is easy to sway back and forth and lose focus, especially with close focus and large apertures. A plain screen like the Rollei original is less prone to reframing and errors. A simple static A/B test will eliminate this possible cause of losing focus. Since I am not the secretary of HHS, I am not going to draw conclusions without sufficient data. He is new to split screens and there are some factors in using them that may need adjustment. I doubt it, but it makes sense to eliminate this at first.

 

[Rayt]

Now, is your Oleson screen designed for 75 or 80mm lens?

What are you talking about?

 

[abruzzi]

Stsrt with a simple field test. Camera nailed in one place. Focus with one screen, then swap in the other screen. Has focus position changed? If so, it is a screen problem.

This is the best test. Taking random shots with one screen then different random shots with the other screen isn’t really a useful test. You want the camera locked in place—usually on a tripod—and some test targets. That are shallow and easy to tell if they are in focus. Focus on the target, no need to take a shot, then without moving anything and without adjusting focus, swap the screen and see if the target still looks in focus. If not, the screens disagree and at that point—if you want—you can burn a roll swapping screens. But for any testing to be conclusive, you need the camera to be fixed in place between swapping screens. If you try this with handholding, you’re only going to get a best guess.

 

[Alan9940]

The 'ole gray matter is pretty old at this point, but I have a vague memory that if a focus screen is swapped out (especially if it's a third-party screen), the focus "system" of the camera needs to be matched to it. I've heard of folks using shims under the screen, etc. Could it be that when a subject looks sharp on the Olsen screen, it's not tack sharp at the film plane?

 

[runswithsizzers]

On my Rolleicord V (that's Rolleicord, not Rolleiflex) the focusing screen mounts under the frame/bracket in the viewfinder. Because the image is focused on the underside of the screen, any change to the thickness of the screen results in moving the focusing surface higher or lower in the optical path, and focusing is adversely affected.

But if I understand @OAPOli correctly, the focusing screens in the Rolleiflex 3.5F cameras mount on top of the viewfinder frame/bracket -- yes? no? If true, then the focusing surface does not change position with thinner or thicker screens.

So any focusing errors are more likely due to:

a. Improper technique which is encouraged by the difficulty of using split screen aid, as described by @Dan Daniel, or

b. Improperly positioned mirror, or

c. Mismatch between adjustments to the focusing distance between the viewing lens and taking lens, or

d. some other variable we have not yet considered

If the focusing error is always off in the same direction by about the same amount, then I would start troubleshooting b & c first.