Is there interest in a New Rapid Rectilinear lens?

TheToadMen

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AgX said:
Best should be barrel design that has space and threading for a commercial shutter, as well as offering a piece of inbetween barrel to be screwed in instead if lacking a shutter.
Click to expand...

And (instead of using Roger's hat) a nice tight lens cap with a grip/handle to be used as a easy shutter.
Would do nicely for paper negatives
 

Regular Rod

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I'm interested for use with 8x10 and Whole Plate sizes. Still have to refer to that famous Australian lady though (Emma Chizzitt)?


RR
 

E. von Hoegh

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The R-R is an interesting lens, it's about as sharp as anything in the center but fades towards the corners; stopping down will improve but not eliminate this. The main remaining aberration is astigmatism, hence the lenses calculated using the 'new' Abbe glasses in the late 1880s/early 1890s being called Anastigmats. If you use say an 8 1/4 or 9 1/2 inch R-R on 4x5, you'll not be using the soft parts and it will behave almost as well as a Dagor or more 'modern' Plasmat.
A multicoated R-R would be very interesting - they have a lot of the same sort of smoothness Dagors are known for.
 

jimgalli

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Party Pooper. RR's have been ubiquitous and cheap for as long as I can remember. Easy to find. Hard to sell. Curious why you would begin there.

Now, the fast and very fast RR's like Eidoscope and Pinkham Series IV, purposefully designed for softness, and even the f4.5 Voigtlaender Series III are worthy of effort. But ordinary RR's, even the f6 Versar's are plentiful enough that there's no way you could manufacture them and have a usable price point.

Of course, my viewpoint is from one who understands a Packard shutter and knows how to use it. You would always have the appeal of modern shutters working for you.
 
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Nodda Duma

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Hi Jimgalli. The RR is just a conversation starter to see where the gaps are. I began there because (no particular reason) except it should be an inexpensive design. How much is an f/6 Verser?

If there's a more desired optic then let me know and I'll take a look. Focal length, f/#, and format will be helpful. You have an optical designer at your disposal
 
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E. von Hoegh

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A 20" f:7.7 Dagor covering say a 60 deg. field, as close as possible to the classic design using modern glasses. I've a link to the original patent drawing with radii and glass data somewhere, if I can find it.

edit - Goerz AG and U.S. patent info - (there was a url link here which no longer exists)
 

Dan Fromm

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E., there's more than one Dagor patent and other makers made Dagor types too. Eric Beltrando has Dagor and other prescriptions taken from patents and, for Boyer Beryls (Dagor types), part of the Boyer archives. They're at dioptrique.info
 

jimgalli

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Are you aware of the 2 examples of classic optics that Cooke re-introduced in the past 10 - ish years or so. Both were classic designs that had gotten in short enough supply that prices might support a limited run of new glass. And that business plan included everything in place to make it happen. The end result is that either Cooke is very very greedy, or you simply can't have a realistic business model to make classic lenses for less than $3000 dollars and make a bit of profit.

Even with that, I never owned any of the Cooke products, although I'm a fan of both designs, I've owned multiple copies of the lenses they copied at penny's on the dollar of what a new one would cost. Even with the rarity.

Not trying to put your fire out. It's fun to talk about. I'm still dreaming of a Pinkham & Smith Series 111 f4 Semi Achromatic lens in about 18" focal length.

A 20" Dagor with same angle of view as an Tessar?? What good is that? The only thing a Dagor has going for it in the first place is it's 80 degree angle of view. 20" with 80+ degrees. That would cause some interest I suppose.
 

David A. Goldfarb

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Another item to think about would be a casket set. Ron Wisner made up some of these with modern optics, and I doubt they've depreciated in value. I'm not sure how many are really out there, but even sets of meniscus lenses like the Busch Vademecum Satz II can sell for good prices, though it would be more interesting to have something of higher resolution.

Wisner also advertised for many years a modern Hypergon for large format, but I've never heard of one actually in existence. That would be interesting.
 

DREW WILEY

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The devil is the shutter. Modern shutters are getting hard to get, and even so, have the distinct disadvantage of having only a limited number
of aperture blades, unlike vintage classic lenses with multi-bladed shutters more appropriate for ideal "bokeh". Or you could just make the lens in barrel and leave it up to the end user to scrounge a shutter for themselves (not always a fun prospect). Getting the right "look" to a
lens is a finicky business, because we all seem to have a slightly different idea of what this means.
 
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Nodda Duma

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Hi Jimgalli.

You can't put a fire out that's been burning for decades. Optical design is my chosen profession, and these days it's all about driving down cost. When I've heard someone say "can't be done" that usually ends up translating to "opportunity". Cost is just a design problem like any other that always has a solution

In any case engineers have thick skin, and I do appreciate the input.


So what other gaps are there to fill?
 
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jimgalli

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Nodda Duma said:
Hi Jimgalli.
So what other gaps are there to fill?
Click to expand...

Thanks. You're a good sport. Another gap that would actually probably sell like hot cakes would be a high quality fast true soft focus lens with a mount that could be used on DSLR's. The cine industry had these in the '30's and '40's for use on 35mm cine for those romantic scenes with glowing highlights. Impossible to find now. There's some junk out there if you like purple fringe areas, but nothing of quality. F4 Rapid Rect design with softness designed in. Even an achromatic doublet could do this job well.
 

Dr Croubie

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Nodda Duma said:
So what other gaps are there to fill?
Click to expand...

I'd say it's almost easier to say what doesn't need to be filled.
4x5 lenses below 300mm are cheap and plentiful, don't bother.
40-60 degree lenses in barrel (Apo Ronar, Tessar, Xenar, Industar) below 500mm also don't bother.

As to the gaps that I can see:
8x10 lenses >80 degrees <200mm <$500 would be nice as I've said.

ULF lenses in barrel 40-60 degrees >600mm (Apo Ronar, Apo Tessar, Apo Nikkor) aren't that rare and aren't ridiculously expensive, but maybe you can compete on price, or especially size (trade a smaller max aperture to make it less than 2kg would make some people happy)?

ULF Lenses >80 degrees seem to be in short supply and expensive, but there's a smaller market for ULF and everyone will want a different length for a different format.

Also the ones with a special 'look' and/or the ones that are expensive for the name and rarity, as already mentioned Petzvals, Heliar, Apo Lanthar, Verito Diffused, Pinkhams, etc.


I'd be also looking at how to mount these in a shutter, the best way that I can think of is:
Offer elements with a smaller-sized screwmount than a regular shutter.
Then make adapters for each sized of shutter above that, eg Copal 3, Alphax/Betax/Acme 4/5, etc, so whatever working shutter I find that's big enough I can order the adapter for that shutter with my elements.
Also make a barrel-mount that will take these elements and keep them correctly-spaced for people to BYO Packards.
 

TheToadMen

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+1
 
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Nodda Duma

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E. von Hoegh

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None of my Dagors - from 6 to 14 inches, New York and Berlin, from 1904 to the eighties - cover 80 degrees at any aperture. Shure, they'll illuminate it. If you're enlarging it, it's a 60 degree lens and sharp to the corners. Schneider specified the coverage of the 14" Kern Dagors at less than that, 53 IIRC.
 

David A. Goldfarb

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However, many of us using Dagors for 8x10" and larger aren't enlarging, and stopped down past f:32 or so they're just fine all the way out to the edge of the circle of illumination for contact prints. I've used a 168mm f:6.8 ser. iii and an 8.25" f:6.8 for 8x10" and a 12" f:6.8 Gold Dot for as large as 11x14" and 7x17". I also have a 16.5" f:7.7 without a flange waiting for a shutter.
 
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Nodda Duma

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David:

What's the illumination falloff look like between center and corners for the 168 f /6.8?
 

Dan Fromm

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Nodda Duma said:
Would a 90 degree (diagonal) zero-distortion 165 mm f/5.6 work?
Click to expand...

Fee, fie, fo, fon,
I smell a biogon.

How much do you expect it will weigh? Cost?

There are already lenses around 150 mm that cover more than 90 degrees and that don't have severe distortion. For example, the 155/6.8 Grandagon-N. Now discontinued and I have no idea how many were sold, how often used ones come to market, or how much they've sold for.

Some years ago Brian Caldwell asserted that he'd designed a low distortion ultrawide with no optical vignetting. Interesting idea, especially given the price and scarcity of the center filters sold to even out illumination at the film plane.

More seriously, formats up to 8x10 are fairly well supplied (come on, all pile on now) with lenses from around .4x to 3-4x normal focal length. Larger formats (but which one to address?) aren't so well served.

The LOMO Petzval and the Petzvar funded by Kickstarter were aimed at small- to medium-format photograpers who want swirly bokeh. The LOMO lens' targets seem to shoot mainly digital. Interesting question is how many LF photographers will give much for such effects. I'm sorry, but I have no idea. FWIW, more people ask where to find high coverage lenses on the LF forum than ask where to find moderate coverage lenses that swirl.
 

David A. Goldfarb

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Nodda Duma said:
David:

What's the illumination falloff look like between center and corners for the 168 f /6.8?
Click to expand...

I'd guess around 2 stops or so, but give it a little extra exposure, and there's enough there to dodge the center when printing and still have a reasonable print. I do the same with the 120mm f:14 Perigraphe, which is wider of course, and has even more falloff of illumination.

The older ser. iii Dagors have more coverage than the later ones. Perhaps the later versions are intentionally vignetted to prevent drift past the circle of good definition.

In general, I'd rather have something there at the edge of the image circle than not, as long as the image quality isn't suddenly radically different (as tends to be with the older Angulons, for instance).
 
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Nodda Duma

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Dan: No, not a Biogon. That's too complicated and costly a lens I think for the format.

More like a double gauss but the outer singlets are negative power to bend the rays in a wide format if that makes sense. Can also look at it as a symmetrical simplified inverse telephoto. 4 elements, f/5.6 at center with light falling off gradually to f/8 at corners of an 8x10 (ie about one stop). Being symmetrical it has no distortion or lateral color. Focus is a little soft (about 50 micron blur size at center), but I haven't really hammered the design too hard and I've stuck to inexpensive glass.

I was tinkering with it today but forgot to bring the prescription home. I'll rebuild it after the kids are asleep and post a layout.


Also another question... I've seen reference to the swirly Petzval bokeh twice now.... Interesting term... My term is uncorrected lateral color coupled with field curvature at field angles or aperture size getting outside the Petzval design space.

Can you elaborate on that and maybe post a photo of what it looks like?
 

Dr Croubie

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Check out the samples on the Dead Link Removed page (AFAIK it's a "true petzval" to the original design).
 

Dan Fromm

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Thanks for the explanation. Re the swirlies, I'm sorry, I've never had a Petzval lens and find the effect very unpleasant. So I can't offer an example. Tastes differ ... Yes, the effect is obtained by using a Petzval lens on a format larger than it was designed to cover. Lens abuse, some say. Creativity, counter the effect's proponents.
 
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