Thanks for pointing that possibility out. I did use it intentionally. Since it hadn't been quoted, I didn't even consider it as a possible "transgression."
DHW Fototechnik in insolvency
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My tests showed that diameter of the feed roller affects only how broad the area on either side of resulting film "kink" is, not the magnitude of maximum displacement away from flatness. Narrower rollers confine the transition area on either side of a kink to fewer mm; larger rollers spread it out of more area.
After discovering the problem, and while hoping to find a camera system that didn't suffer from it, I borrowed a friend's 500C and A12 to include in my testing. Unfortunately, film bulging was even worse than the other cameras then in my possession.
After evaluating the results of all this, I concluded there are only two ways to have flat acetate-based roll film (and critically sharp results) when using a 120 medium format camera. Either choose one with a straight feed path, like the Fuji and Mamiya rangefinders, Mamiya C-series TLRs, Minolta Autocord and Pentax 67, or, with other cameras, i.e. those with bent feed paths, use twice as much film. In other words, load the film, advance to frame one, expose, then leave it there. When next ready to make a picture, advance to frame 2, cover the lens and fire the shutter to cause a blank, then rapidly advance to frame 3, on which the second "real" exposure will find a perfectly flat segment of film. Continue alternating to the end of the roll. Not economical, but very effective.
After reviewing my notes on this from the late 1990s, it seems there's another typo. Should be "as little as 15 seconds."
what about the Mayiya RB67 and the M645. There the film is basically doubled back over a 6 mm roller.
Substantial bulges with both cameras' holders unless the skip-every-other-frame approach is taken.
In that case, the film was held between the pressure plate in back and the Reseau plate in front.
Take a camera designed with a folded film path. Load up a test roll. Let it sit on the counter overnight. Then remove the roll and look closely at its surface. THAT observation should supply the definitive input on this subject...
Ken
Nope, the Reseau plate was not "some distance" from the film. It was doing its intended job keeping things flat despite the reverse-curl-feed-roller-induced bulges.
Note that this was before the days of Acros, TMAX 100 and Ektar with their glossy emulsions. Ektachrome's rather dull emulsion surface had no danger of creating Newton's rings.
And Kodak was a space contractor, so you can be sure they had tested things out thoroughly, they also had to make a special batch of film for space as the normal Acetate base apparently does not like to live in a vacuum, and so NASA needed Polyester film. if they had of seen the need to treat the surface to avoid Newton rings, they would have.
Also, does the 70mm back induce the same curl?Nope, the Reseau plate was not "some distance" from the film. It was doing its intended job keeping things flat despite the reverse-curl-feed-roller-induced bulges.
As I understand it, a polyester base was more dimensionally stable, and being very resistant to breakage could be made thinner to allow more pictures per roll.
Sorry, I've never seen a 70mm back, so don't know. However, it seems unlikely that it would feed directly off a supply spool into the exposure area without making a bend, so the answer is "probably."
When you load it you leave it at the arrows until you need frame1. Shoot the other 11 or 23 promptly.
Some Rollis have a glass plate to improve flatness
The Blads on the moon had (still have) a graticule plate which would have helped like the Rollis.
But for practical use a Mamiya or Minolta TLR are simpler.
That is the aforementioned Reseau plate.
add-up on DHW
Their director (now under control of the trustee) gave an interview.
He stated that causes for their financial trouble were the reduction of toll-manufacturing orders by their clients as well as failed attempts to gain investors for new projects.
From this I conclude that their "Rollei" business was not substantially lacking sales. That he too claimed that marketing this "Rollei" sector is their weak point seems to point at them believing in more chances for their cameras and projectors.
Furthermore he stated that production of all the following Rollei products (thus less than seen at their weebsite) is going on:
the TLR'S,
Hy6 Mod2 with two film backs,
lenses
35,
the projectors
For a computer-controlled version of their electronic LF shutter, that won't have a proprietary control unit any longer he sees a future market, as successor to Copal shutters.
The same for a 35mm MF lens and other prime lenses.
DHW is goíng on with talks with investors out of their sales cicuit to gain a future for the enterprise and its 40 employees.
Their director (now under control of the trustee) gave an interview.
He stated that causes for their financial trouble were the reduction of toll-manufacturing orders by their clients as well as failed attempts to gain investors for new projects.
From this I conclude that their "Rollei" business was not substantially lacking sales. That he too claimed that marketing this "Rollei" sector is their weak point seems to point at them believing in more chances for their cameras and projectors.
Furthermore he stated that production of all the following Rollei products (thus less than seen at their weebsite) is going on:
the TLR'S,
Hy6 Mod2 with two film backs,
lenses
35,
the projectors
For a computer-controlled version of their electronic LF shutter, that won't have a proprietary control unit any longer he sees a future market, as successor to Copal shutters.
The same for a 35mm MF lens and other prime lenses.
DHW is goíng on with talks with investors out of their sales cicuit to gain a future for the enterprise and its 40 employees.
Perhaps Hasselblad should buy them out - at least they would have a decent 6x6 film/digi camera again! 
Trimble Navigation and Impossible Project to name a photographic and a non-photographic client.
I hope that they are able to survive. Although I doubt I would ever be able to afford a brand new Rolleiflex, it would be quite an experience to own one. I thought that Impossible was partnering with them to make the film processing unit for their instant lab and cameras, but I am wondering if this was just for research and development, or also for manufacturing going forward.
Thye are no longer working for Impossible. What still can mean both.
Anyway even manufacturing for them (alone) seems hardly be realistic to save the company.
There is no news about their current state. I shall keep you informed.
Anyway even manufacturing for them (alone) seems hardly be realistic to save the company.
There is no news about their current state. I shall keep you informed.
Do you think that there is anything that could realistically save them? Do they gain any royalties from sales of Rollei branded films?
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