Rolleiflex Tele - Flat Glass and Pressure Plate Setting

[robdeszan]

Dearl All,

I am struggling to find manuals or information on the function of Tele's pressure plate settings.

I understand that the 35mm setting brings it closer the film as a 35mm film roll does not have backing paper.

Between the 6x6 (with no flat glass installed) and 6x6 (with the glass plate installed) settings, though, which one of these brings the pressure plate furthest from the film plane? Am I right to assume it is the latter, to account for the added flat glass and paper?

If so, does the film flatness suffer if you shoot with the plate in 6x6-with-glass-installed position but without the actual glass installed, or is it irrelevant?

Many thanks!

 

[DownUnder]

I got a flat glass insert with the Tele Rollei I bought in the 1980s. It came with a lovely small matching case and a sheet of instructions, in German of course. Not having Google Translate back then, I put the entire thing away in a drawer and forgot about it. Took it out now and then to dust it off.

Yup, I never used it. All the Rollei photographers I met said the same thing - it just added another layer of glass to the lens.

Someone told me that was a must-have accessory for neurotic German photographers. I had to agree.

When I sold the Tele I kept that glass as it also goes into my 3.5 E2. I know because I put it in once, and then took it out. Never did anything with it again.

That glass is still somewhere at home. I must take it out and flog it on Ebay for the price of a return flight to Bali...

As for the camera setting for that glass, I'll dig out one of my Rollei guides when I'm home in Australia again, and get back to you about it. Unless of course someone else here beats me to it.

 

[pixie79]

I used Mamiyaflex Twin Lens, 180mm! It was actualy too sharp for portraits! Why was Mamiya better than Rollei? Film ran in straight line! Here a snap from Rollei Automat! Sub zero weather! I didn't last long! OD film not recomended! One

 

[TenEleven]

Just a couple of thoughts:

Yes most Japanese cameras have more sensible film transport layouts, but this also means if the film curls the other way (in humid weather, common in Tokyo) you now have flatness problems, too. It's a real damned if you do and damned if you don't situation.

Another thing that I heard about the glass plate, that I have not seen mentioned here is that it turned the film into scratch city (I can believe it) and also, if there is a piece of dust on the other side of the glass you are in trouble. Because just like sensor dust on digital - the dust sits quite close to the imaging plane, so that it will be rendered sharply onto each and every negative until you clean it off - which of course you can't mid-roll.

Regarding your question: The pressure plate - regardless of camera - should be set correctly. The "glass" setting will, if I recall correctly, lower the tension of the pressure plate to make room for the glass. This means without the glass the film will flop around in the breeze and that is likely to affect sharpness negatively.

That all being said, I never had sharpness issues that I could clearly attribute to the film going around a bend in my Rolleiflexes. Even after thousand rolls and some of the rolls sitting for days. Yes there were sometimes weird quirks and blips (and lots of user error!) but never anything that indicated clearly that the film had a kink. In my thinking, if it were actually such a massive detriment to the imaging, then everyone using their Hasselblad and praising the Zeiss lenses would be mistaken. In the Hasselblad magazine backs the film makes a rather convoluted path before being exposed - yet almost everyone universally agrees that these are some of the sharpest lenses made for 120 film.

 

[robdeszan]

Thanks All for the interesting insights

The reason I am asking is that I am testing a recently-serviced Tele here wich came with a flat glass back (no glass though) and I have been struggling to get consistent focusing accuracy wide open. At close and mid distances, though, especially at f4 I was seeing softness in the middle of the frame but tack sharp left and right frame edges(?) - you normally expect things to be the other way round wide open; it only improved once stopped down to 5.6, better still at at f8.

Both the taking and viewing lens are definitely in sync, and the focusing screen and film plane are spot on (had to shim the focusing screen by 0.36mm to achieve that), perfectly focusing at further distances too, with hard infinity stop being sharp. All verified with a focusing screen in the film bay*, X10 magnifying loupe, and even an improvised collimator (I previously calibrated my 80mm 2.8f model in the same way). I made sure the film was tight when loading etc.


I re-shot, rescanned etc. to rule out human error but it was still there...

I concluded it was related to film flatness as the focus across the frame checked out 100%. So I inspected the back to make sure it was straight and then noticed that the pressure plate was set to the 6x6-setting-with-the-glass-installed and not regular 6x6... I think I did not pay attention to this detail because there was no glass included - I had assumed it would be set up accordingly.

Now that you confirmed the change in height, it could explain the middle softness I am seeing in the scans - with the film not being pushed far enough - and being allowed to curve too much.

Will still test with film, of course, but I am hopeful now!

* Just to add to this aspect, a discussion I stumbled across on phot net contains this bit of info on camera calibration:

"[...] Rollei took into account that the film bows out towards the lens a bit, and had a calibrating screen that was actually inset into the opening at the film plane a small amount. Many cameras have been adjusted by using a regular flat ground glass, and this can throw the taking lens and viewing screen out of sync slightly. At f8.0, you probably won't see it, but at f2.8 and 4.0, it can make a big difference if everything isn't perfect."

Not that I noticed it with the 2.8f (I used a flat ground glass) - is that something you account for when calibrating? Could this be a factor here at f4 because of a longer focal length?

 

[robdeszan]

I hate to see inconclusive posts online so here's my update.

The incorrect plate setting was DEFINITELY affecting focus accuracy. Once the plate was set to regular 6x6 position the focus plane was evened out, the soft centre frame disappeared.

Shot at f4 centre of image (top is a 6x6 setting, the bottom the incorrect 6x6-with-glass)


Here, the same frame, with the crop demonstrating the focusing plane shift between the centre of the frame and edges due to the film not being held by the plate. The transition (look at the LHS edge of the wooden fence) is not as pronounced as with the incorrect setting below. Coming back to the question of the flat glass, I think one could argue that you could still improve the overall film flatness with it as there is still some sharpness fall off. I am sure there are benefits, otherwise Rollei would not have explored it.



This is a Rolleinar 0.35 shot - LHS the pressure plate at the incorrect glass setting (at f4.5), RHS the pressure plate is at the correct regular 6x6 (at f4).


Finally, have a look at the hard-stop infinity sharpness (both at f5.6 with a B+W yellow filter as it was a bit too bright for the iso) and the horizon trees and buildings, the chimney is about 35-40m away. 6x6 plate setting at the top, the incorrect 6x6 with glass at the bottom. You can see the image is clearly front focused - something which has been consistent when I was testing with the incorrect setting.



I think there may still be room for a tiny bit of improvement - raising the focusing screen by another fraction of a mm perhaps - but since the film is not held 100% flat without the glass (a modern version available here from magicflexcamera, would love to test one, but € 285 is a bit much) I won't achieve the consistency required for such fine adjustments. I would also need a finer ground glass for the film plane (I have diy one), possibly a finer ground glass in Rollei's viewfinder too. I shot for many years on a Mamiya RZ and a P1 digital back and habits developed there - it had to be extremely accurate! I frankensteined a custom viewfinder and a hood to get there - made me sensitive to focusing screen setups; film is much more forgiving in this respect. There is also the question of practical implications (I prefer to use a prism finder and it is inherently dimmer) & dynamics of say, a portrait shoot, and all this getting in the way of capturing fleeting moments and expressions vs ultimate focus accuracy... by the time you stop down to f8 (I often start at that aperture) the differences disappear completely.

Anyway, the camera tests fine, which was the whole point of this exercise. 🙂

 

[Rayt]

Film flatness is valid concern with Rolleiflex and Hasselblad 500/2000 series due to the twists and turns of the film path. This is why I always finish the entire roll and never let film sit in the camera or back overnight. Simple enough to finish 12 frames. I have the Rolleiwide and 2.8 and 3.5 Rolleiflex as well as various Hasselblads over the years never had film flatness issues in actual use, and the above has been my only rule. I never owned a tele rollei because 150mm lenses for the Hasselblad are common and convenient.

 

[robdeszan]

Hi Ray

It appears that the longer focal length on the Tele makes it more critical, the 80mm was more forgiving when I adjusted it, or maybe I got lucky...

Since my last post I have adjusted the shimming further from 0.36mm down to 0.34mm (by combining different tapes) and that, again, made a positive difference wide open, especially at further distances. I had to buy a better slide viewing loupe and made a finer focusing screen to achieve that though.

It is a stunning lens BTW, edge to edge. The 0.35 and 0.7 rolleinars are also impressive - especially given the "relaxed" mount on the former, it is hardly tight when mounted on the front bayonet. I was expecting more image deterioration but they do not in the way of iq at all.

 

[Freakscene]

You got lucky. It is less critical in a tele than in a regular Rollei. Telephoto lenses have more tolerance for the behind-the-node distance (and shallow depth of field in front), whereas wider lenses have less tolerance behind the node (and more depth of field in front).