Focusing a TLR

George Collier · Mar 27, 2010

I took some pictures last roll of film of some manikins, two of them, very close to the camera (Rollie 3.5T) I moved as close as the camera would focus (about a meter), then back a bit so that I could move the focus back away from the closest point. I used f/5.6 to minimize DOF, but not wide open. I took 3 shots - first focused on the closest manikin, second focused on the far manikin (two feet further away), then stopped way down for the third shot, and used the distance scale to set the focus to include both manikins with the greater DOF. I was very careful in focusing to be sure the pop up viewing magnifier was well positioned.
Both negs from the first 2 shots indicated focus was further out than I thought I saw on the ground glass (the first shot was actually closer to the farther manikin, and the second looked just beyond the farther manikin) the stopped down one is ok, too hard to tell where the center point is.
I just had my 3.T serviced (Krimar), and one of the things he did was calibrate the focusing. Is it possible that the focusing lens could be in focus, and the taking lens out of focus to that extent? I'm not concerned that the distance scale is accurate, just agreement between the lenses. I have never had this problem, although I don't normally focus this close.
I'm going to run another more controlled test with wide aperture, with gradually distant subjects marked, etc, like those old DOF examples you used to see in books, and record everything, and might call Krimar if it repeats itself, but I just wanted to toss this out to see if anyone has any advice.

unclemack · Mar 27, 2010

If you were hand-held did you maybe tilt or lift a little to compensate for parallax and lose critical focus?
As you already know a controlled test will determine whether a problem exists or not. If you have a screen you can use on the film rails you don't need to use film.

Slixtiesix · Mar 27, 2010

You should definetely use a tripod for further testing. Moving a camera with waist level finder out of focus happens easily.
Best regards, Benjamin

fotch · Mar 27, 2010

You may want to test using a test target or a newspaper. Keep it straight on, no angles, camera on tripod, and test using ground glass focus with a magnifier, then follow with a ruler/distance scale shot. All wide open, starting at 3 foot or what ever the close focus is, then 4 foot, then 5 foot, then compare.

Maybe the repair guy did not get it right.

Jon Shiu · Mar 27, 2010

I suggest opening the back and placing some frosted celo tape across the film rails. Then view something like a light bulb. You can use a magnifier if you want. The tape acts as a ground glass at the film plane to confirm focus of the viewfinder.It is a little awkward with a TLR, but you can figure out a way of keeping the same distance from camera to subject when first focusing by viewfinder, and then by frosted tape.

Jon

George Collier · Mar 27, 2010

Thanks, guys, for the responses. I failed to mention that it was on a heavy duty Bogen that I normally use for the 4x5, with cable release. I didn't think to mention it, because I hardly ever shoot hand held any more, except occasional 35mm.

JPD · Mar 27, 2010

Jon Shiu said:
I suggest opening the back and placing some frosted celo tape across the film rails.

Better yet, is to cut a piece of flat clear plastic, like the lid on a CD case, to fit the film chamber. Then put matte Scotch Magic tape strips on one side, and you will have a cheap, fine grained and usable viewing screen.

ic-racer · Mar 27, 2010

Both negs from the first 2 shots indicated focus was further out than I thought I saw on the ground glass

"Film bulge"
The major problem with 120 film: it won't hold flat all the time. The film cannot bulge back behind the pressure plate, it can only come forward. Therefore, the focus shift is always behind the subject.

Unless you have a vacuum back, the effects can be random. For critical work I bracket the focus. Also, pay attention to the time between shots. If the film sits for 2 years straddling a roller, when it is pulled into the gate it likely will bulge.

I have heard of 'advice' from seasoned professionals that seems to correct the problem, without exactly knowing the problem. One set of advice involves doing landscape work at the hyperfocal distance. In this case when the film bulges, it puts the image right at infinity (where you want to be).
The second is to focus a portrait just in front of the subject. Again, when the film bulges, it will bring the subject into focus.

Rolleiflexible · Mar 27, 2010

Did you use a center-spot focusing aid, then
move the camera to compose for the shot?
This is a common mistake newcomers to
Rolleiflexes make -- if you are shooting close
to your subject, with a wide aperture, you
will end up with the focus off in the way you
have observed. The fix is to ignore the
center spot and teach yourself to focus on
the glass, without moving the camera to
recompose after you focus.

It is not "film bulge" -- not a Rolleiflex issue.

Rolleijoe · Mar 29, 2010

You don't need a tripod just to focus with a Rollei TLR. That's ridiculous. There is a focus distance scale in plain site, on your focusing knob. It'll tell you everything that's going on, with how you've set your critical focus. Just read it, and trust it.

Tripods are insane with a simple TLR. They're fast/hand-held beauties. I've been shooting with Rollei TLRs for decades, and believe me, they're just about as perfect as it gets.

ic-racer · Mar 29, 2010

Rolleiflexible said:
It is not "film bulge" -- not a Rolleiflex issue.

Zeiss and Rollei do not agree with your statement.

Zeiss can also trace causes for lack of sharpness in customer's photos. This is particularly interesting since more than 99% of all customer complaints about lacking sharpness in their photos can be attributed to misalignments of critical components in camera, viewfinder, or magazine, focus errors, camera shake and vibrations, film curvature, and other reasons.

So far, Zeiss has found that film curvature can have a major influence as a source of unsharpness. This has also been known by Zeiss' camera making partners Alpa, Hasselblad, Kyocera (Contax) and Rollei.

Zeiss "Camera Lens News #10"

Shawn Dougherty · Mar 29, 2010

Rolleijoe said:
Tripods are insane with a simple TLR.

Then call me crazy! I love using my Rolleiflex T with the ball head on my wooden tripod. Just a tool, man. Mileage may vary. =)

dpurdy · Mar 29, 2010

TRIPOD don't leave home without it. With my Rolleiflex I like to use slow film and stop down.

Dennis
I have looked at film going through my Rollei with the back open and I think the only time you will see film bulge is if it sat n the camera a long time and picked up a curl memory on the next frame. But I doubt it even then.

Rolleiflexible · Mar 29, 2010

ic-racer said:
Zeiss and Rollei do not agree with your statement.

Franke & Heidecke made a lot of Rolleiflex
models with Zeiss lenses. If you look at
the film path of a Rolleiflex TLR (as opposed
to, say, a Rolleiflex SL35), you will quickly
realize that film bulge isn't going to happen
in the TLR models.

On tripods: I find that the form factor of
a Rolleiflex TLR makes them well-suited to
shooting handheld even at shutter speeds of
one second. That said, it is also true that,
even for a Rolleiflex, a camera off a tripod
is a camera in motion.

twoeyeandy · Mar 30, 2010

George Collier said:
.
I just had my 3.T serviced (Krimar), and one of the things he did was calibrate the focusing. Is it possible that the focusing lens could be in focus, and the taking lens out of focus to that extent? I'm not concerned that the distance scale is accurate, just agreement between the lenses. I have never had this problem, although I don't normally focus this close.
.

So is this possible? One lens in focus and the other out of focus??
Ta Andy

paul ron · Mar 30, 2010

Yes it is possable for the viewing lens not to agree with the taking lens and that is exactly what the reapirmen is suposed to adjust. If it was serviced and it was adjusted, the reapimen focused the viewing lens to agree with the ttaker for infinity on his collimeter.

In general for any TLR, or for most any camera... you put a GG on the film plane. On a tripod, focus the film plane to a target at a measured distance, like a well lit news paper if you don't have a collimeter. Check the focusing scale to see the distance agrees with your measured distance... if not see if it focuses at infinity properly. If not the taking lens need to be adjusted to infinty first n check the distance again.

Carefully focus it using a loupe for the sharpest image. Now look at the view screen with the loupe n see if it agrees with the taker.

If not... you either focus the screen if it has a height adjustment, or you adjsut the viewing lens to agree.

Film bulge can be a problem in any camera if there isn't enough tension on the film when winding or the preasue plate is not tight. Are your exposed rolls loose?

Now if the service was just done, and all the tests say it is in focus.... maybe it is focused properly n you just need a diopter instead, your eyes may be a problem? Do you wear reading glasses?

.

36cm2 · Mar 30, 2010

Another vote for the Rolleiflex on a tripod. It's even sexier with legs.

Ken Ruth, of Bald Mountain photo, once told me that in even the most precisely machined rollfilm cameras he's serviced (i.e. Leicas) film bulge is an issue. He's watched the bulge "pop" on hundreds of cameras serviced and recommends that, if you want to minimize the effect, allow no more than 60 seconds from the time you advance the film to the time you expose it. In his observation it takes that little time for a bulge to regularly occur.

Rolleiflexible · Mar 30, 2010

I'm sorry. If the camera is consistently out of
focus, I will bet my apartment that it is not film
bulge. I have shot, literally, over 10,000 rolls
through an assortment of Rolleiflexes, including
two Tele Rolleiflexes, of people close-up, and
nearly all at wide apertures, and it is the rare
roll that is not perfectly focused on the irises of
my subjects' eyes -- and that is so whether the
eyes are in the center of the frame or at the very
edge. If the film did not lie precisely on the film
plane, I would not be able reliably, consistently,
to shoot focused work with a Tele Rolleiflex,
with its 135mm lens, at f/4, 18 inches from my
subjects -- yet I have shot like this hundreds of
times, and each time the shots come out focused
as I expect them to.

I respect Ken Ruth, but his remarks, in my experience,
do not apply to Rolleiflex TLRs. There is no way George's
problem arises from film bulging in the film plane.

JPD · Mar 30, 2010

I agree with Rolleiflexible. I've never had a problem with film bulging in any of the maybe thirty Rollei TLRs I have owned and used. If there is a bulge in the film, it must be tiny.

However, it can be an issue one must account for in some cameras. Folders, for example, where the film travels in a straight path. Using a ground glass in the films position is then often not enough when adjusting the infinity focus. When I adjusted the focus on my 6x9 Zeiss Ercona II (with front element focusing), I first used a GG at the back, and then took a test roll and turned the front element in 1mm steps between each shot. The best focus was ca 5mm away from the mark I had made (where the focus looked perfect on the perfectly flat GG in the film gate). The procedure cost me a film roll and a couple of hours, but it was worth it. I found the coated Tessar on the Ercona to be VERY sharp and contrasty.

Q.G. · Mar 30, 2010

36cm2 said:
Ken Ruth, of Bald Mountain photo, once told me that in even the most precisely machined rollfilm cameras he's serviced (i.e. Leicas) film bulge is an issue. He's watched the bulge "pop" on hundreds of cameras serviced and recommends that, if you want to minimize the effect, allow no more than 60 seconds from the time you advance the film to the time you expose it. In his observation it takes that little time for a bulge to regularly occur.

Bulges don't pop.
It's not the time between advancing and exposing, as much as between exposing and advancing.

The bulge (according to Zeiss) is a bend in the film that was left to sit bent for too long.
Film will flex, they say, so if you pull film over a roller or through another bend, it will very soon flatten again. No worries.

But not, they say, when it has been sitting around that roller or in that bend for a while. Then, they say, it will develop a memory, and not go flat again quick enough.
So the curve created when it was sitting around a roller before entering the film gate will become a bulge that will be transported into the film gate, lifting the film out of the film plane when it is going to be exposed.
Unless, they say, you don't allow it enough time to develop that persistent bulge.

Rather puzzling, since (as we all know) film has been wrapped around a plastic spool for ages already when we finally put it in our cameras. So that persistent bend/curl should be a problem even when we do not allow it to sit around other, new bends for a longer or (as per Zeiss' recommendations) shorter while.

But to put Zeiss' publication in perspective: it concluded that bulge is a problem.
But less so when you use 220 film.
Even less so when you use a vacuum back.

Was it pure coincidence that vacuum backs only work with 220 film, and that Zeiss' Contax brand was promoting their brand spanking new vacuum back?
I think not.
The message of Zeiss' publication was that we should spend money buying a Zeiss/Contax camera, and all those beautiful Zeiss lenses that you need with one of those.

36cm2 · Mar 30, 2010

Ok, let's see.

Rolleiflexible, I agree with you that if the OP's photos are consistently out of focus then the problem is unlikely film bulge. I have experienced film bulge on my folder and I believe I've also experienced it on my Rolleiflex, but it's not the type of problem that presents itself consistently. I mentioned my conversation with Ken as advice that I've found helpful in dealing with film bulge, not as the solution to the OPs problem. I should have been clearer on that, but the other posters' advice on checking focus was already adequate. I think the OP's lenses are either incorrectly focused (although I've had my Rollei serviced by Krimar and he's done great work) or his focus technique is flawed. After reading this thread I'm pretty sure that my focus technique with the Rolleiflex is flawed and can be improved.

Q.G., I disagree that bulges don't pop. I didn't get into the details of my conversation with Ken for fear of misrelaying his comments, but I believe he was saying that acetate film base is deformed by any curl feed rolling system and will have a tendency to bulge toward the lens following that deformation. Tensioners in an advance system are designed to restrict that tendency, but high humidity and temperature exacerbate the tendency and when you advance the film you expose the film more directly to those elements. In his experience, it only takes about a minute for those elements and any slip in the tensioning system to allow the recently induced bulge of the film base to pop. So, if you can minimize the amount of time that film has to bulge right after being advanced, that's helpful. Don't confuse this with a situation where you have left a camera with film in it idle for a long period. In that case I advance two frames before shooting, because you're sure to have a strong memory-induced bulge from the film sitting on the rollers. Some cameras have their rollers spaced so this type of bulge lands outside of the film exposure area when advanced, but I don't know if the Rolleiflex is one of them.

Sorry for the long-winded response. To put this all in perspective for the OP, check your camera's focus again with the great advice others have left. Don't worry about film-bulge. Shift happens.

Rolleiflexible · Mar 30, 2010

36cm2 said:
Another vote for the Rolleiflex on a tripod. It's even sexier with legs.

By coincidence I came across this photograph
by Jan Scholz over on Flickr:

http://www.flickr.com/photos/micmojo/4424757937/

Jan seems to have confirmed your observation.

Shawn Dougherty · Mar 30, 2010

Alright! =)

George Collier · Apr 3, 2010

Thanks for all the posts, guys. I have taken and processed another roll, which looks better, but I need to scan. I have been taken out of my photo activities lately by other pressing needs, will post scans when I can.

ic-racer · Apr 4, 2010

Rolleiflexible said:
If you look at
the film path of a Rolleiflex TLR (as opposed
to, say, a Rolleiflex SL35), you will quickly
realize that film bulge isn't going to happen
in the TLR models.

Film bulge does happen with Rolleiflex TLRs. In fact they made a glass plate that fits in front of the film to eliminate the problem.

The problem was eliminated in the motorized 6x6 SLRs with the vacuum back.

Focusing a TLR

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