Is there interest in a New Rapid Rectilinear lens?

[Nodda Duma]

Sorry, still waiting on the barrel design.

 

[LJH]

Thanks. I'll keep an eye out for your next update. Looking forward to reading it!

 

[pdeeh]

wonder where you're up to with this, Jason ?

 

[Nodda Duma]

The barrel designer never delivered a design, so I've contacted another mechanical engineer to design one. He is currently looking at it. The barrel would be either aluminum or stainless steel. I'd put a nice black finish with shiny trim on it, and black painted internals for light control. I would include a dummy center barrel which the purchaser could swap out with his/her own Copal #1 shutter. The dummy center barrel would probably include Waterhouse stops, and you'd make your exposure with your lens cap.

I did get optics quoted. I went to several vendors that have generally given me very competitive pricing as well as very good quality. The quoting includes modern multi-layer coatings, designed for the spectral band that film is sensitive to. Of course, I don't have mechanicals to quote, but I know enough to gauge the pricing and include it in the estimate above. From this I estimated the end cost (in US$) vs. quantity, and it was something like this:

​

[TABLE="width: 146"]

[TD="align: center"]Quantity [/TD]
[TD="align: center"] per unit
cost
[/TD]


[TD="align: center"]3[/TD]
[TD="align: center"]5000[/TD]


[TD="align: center"]20[/TD]
[TD="align: center"]1750[/TD]


[TD="align: center"]50[/TD]
[TD="align: center"]1250
[/TD]


[TD="align: center"]100[/TD]
[TD="align: center"]750
[/TD]


[TD="align: center"]500[/TD]
[TD="align: center"]375
[/TD]

[/TABLE]

​

So for example, if 3 people agreed to purchase the lens, then they would pay ~$5000 each.

If 500 people agreed to purchase the lens, then they would pay just ~$375 each. This value tells me I actually did pretty well in reducing cost. However, I think this type of quantity is a pipe dream... more realistically I'd think 20 people or so would be interested. But I have no real way of predicting how many would buy them at this time.

The pricing is very rough.. but it gives you an idea of how pricing benefits from volume production. It also shows you why there's not many new lenses being made for large format....you just can't compete on price with used lenses.


So that's where it stands. You now know as much as I know.

-Jason

 

[pdeeh]

thanks

 

[rthollenbeck]

What do you expect the coverage to be?

 

[Nodda Duma]

I don't recall exactly what the coverage was, but it was enough for 8x10 and some bit of movement. The information is posted in one of my posts above.

 

[JPD]

I've read the whole thread with interest, and it started with discussing an RR type of lens, and then other possible designs, and then a Super Angulon deriviated type, and costs. And you have settled on that. I have nothing to say about that, but I've been thinking about classic designs.

An oldie is the ICA Hekla 6.8 four element Double-Gauss that was cheap but nice and sharp. What advantages or disadvantages would this design have compared to the one you're working on, except that it's a normal lens and not wide?

 

[Nodda Duma]

Well it's kind of an apples-to-oranges because the four element double gauss wouldn't fair too well converting design-wise to a wide-angle lens. It's kind of like comparing a utility truck to a motorcycle. Which one is better? Well it depends on what you want to do.

As it is the four-element double gauss gives you color fringing (ie soft focus for B&W) at too fast an aperture. I'm not sure I'd use it as a starting point.

One note: The design above isn't derived from the Super Angulon. It's not even close. The designs correct over the wide field angle in distinctly different ways.

 

[Dan Fromm]

Jason, there have been a fair number of 4/4 double Gauss type w/a lenses. The Wide Field Ektar, f/6.8 Wollensak wide angles, Meyer Aristostigmat, Cooke Ser. VIIb, ... Many claim to cover 100 degrees at small apertures.

 

[Nodda Duma]

Ah yes you're absolutely right. That's what I get for browsing the forum in a brain-sucking meeting. May I call mulligan for that brain fart?

 

[JPD]

Jason, there have been a fair number of 4/4 double Gauss type w/a lenses. The Wide Field Ektar, f/6.8 Wollensak wide angles, Meyer Aristostigmat, Cooke Ser. VIIb, ... Many claim to cover 100 degrees at small apertures.

Yes, and they are not bad at all.

Meyer Wide Angle Aristostigmat:

http://home.vasina.net/?page_id=1042

I only had the Hekla lens in mind, because it's the only lens of this type I own, and it's a normal.

 

[rich1911]

Hey Jason,

Whatever happened to this?

Thanks, Rich

 

[Qebs]

Hey everyone,

Does anyone know if this project went anywhere?

I would love a lens for 20x24"!

Thanks
Cheers,
Kevin H.

 

[Nodda Duma]

I’m still around. People who ask for one-off lenses usually end the conversation when I inform them that single-unit examples cost somewhere between $5000 - $10,000. Obviously nobody’s pocket is that deep. Prices don’t go down until you’re making hundreds or thousand unit production runs.

I’m still doing optics by day. On the side I started producing dry plates in any size people might want

 

[AgX]

Leaving the design costs aside, they must of course be spread somehow over the sold lenses, in times of machinery enabling custom manufacturin of single lens elements without customized tools one should expect a reduction of costs for single lenses.

 

[Nodda Duma]

Leaving the design costs aside, they must of course be spread somehow over the sold lenses, in times of machinery enabling custom manufacturin of single lens elements without customized tools one should expect a reduction of costs for single lenses.

Nope. Those numbers are real numbers for prototype quantities of custom lenses, not the NRE (design cost). I’m pretty well tapped into the worldwide optical production and I have quotes in front of me now from some of the cheapest acceptable quality shops on earth.

Fabricaring optics is labor intensive even today. The tool used must match the radius of curvature. Shops have pre-made tooling which they characterize and list, but matching the design radii to those only saves you some $$ in the 100-500 quantity range. The real cost is in the grinding and polishing, and you don’t get cost savings until you can spread that labor over many glass blanks being blocked for polishing all at once. You need to order about 500 or so of a lens to get down near the glass material cost which is of course the floor for lens pricing.

 

[RalphLambrecht]

Hi folks,

I am a lens designer. I have been a lens designer for quite some time. I've designed camera lenses, objective lenses, telescopes, eyepieces, and so on and so forth. I've designed in the visible, in the thermal, in the UV, and even dabbled in "microwave lenses". I've fabricated lenses, assembled lenses, tested lenses, and destroyed them to see how they fail (a necessary evil). While my official degree is an MSEE, I never did electrical engineering. I took a couple optics electives, got interested in them, highlighted them on my resume and was hired by the Navy into an optical imaging group where I worked for many years. There I taught myself design. At some point I actually went back to school (University of Arizona's Optical Sciences Center) to get the formal classes. Now I work as a lens designer.

My hobby ties into my professional work.

I am a new member to APUG but have enjoyed film photography as a hobby even back when it was just called "photography". I joined to keep up to date on the latest trends in film and camera equipment, as I've seen cost of equipment go down and then creep back up.


So I know the classical optical designs very well. I saw a thread about a Petzval Kickstarter project, and was kind of surprised at the level of interest (but maybe not so surprising). So that got me thinking...



Is there interest in classical camera lenses such as the Rapid Rectilinear, Dagor, etc, reviving them for use with modern cameras?

I would love to revisit the old designs and see the designs become real lenses. That is my passion and why I'm a lens designer.


I think there is, and I'm considering the idea of a Kickstarter. I would start (but not end) with the Rapid Rectilinear... a design which I think provides beautiful photos in a normal format focal length. The original design is well-documented, but unfortunately the glass types called out are no longer made. The first step is updating the design, which I have done. It does what the RR did originally, and looking at the simulated images, the Bokeh is really nice. The focus is sharp but if I move one of the lenses the focus gets softer. Adjusting the softness of the focus could be a feature!

My starting design is a 13.75" f/6 or f/8, for use with an 8" x 10" film, giving a field of view of ~40 degrees by 32 degrees on that film (50 degree diagonal). Does that sound like a useful lens? I am looking for feedback in this regard. I can tune the focal length easily enough while it is in Zemax.

I would use modern materials for the housing such as aluminum or plastic... whatever is appropriate to maintain lens position within tolerances over temperature. I could give it a classic look or a sleek modern look, but more on that later.

Here is a layout of the preliminary design (if I successfully upload).

The design can of course be used for other formats: Scaling of the focal length accomplishes that but it'd be different production runs.






​

Unfortunately8x10 is not part of my repertoire but a 4x5 les would be of interest.

 

[Ian Grant]

Part of the problem is good second-hand RR lenses for most formats are still quite easy to find, I found an excellent 20".RR for my 12"x10" camera earlier this year for £120, approx $154 US, one that covers 5x4 would be much less.

Ian

 

[Nodda Duma]

Part of the problem is good second-hand RR lenses for most formats are still quite easy to find, I found an excellent 20".RR for my 12"x10" camera earlier this year for £120, approx $154 US, one that covers 5x4 would be much less.

Ian

Yes ... for most formats. Most of the inquiries I've received were for Ultra Large Formats where the cost of available optics (multiple $K) starts to approach the cost of a new design effort (which can be about $8k - $10k and go up from there). Of course, the inquiries usually cease when they see an actual quote. But, compared to the optics from a hobby like astrophotography or a modern really fast super-zoom lens (and especially that 1600mm f/5.6 Leica), the price isn't too bad.

- Jason

 

[alanrockwood]

Yes ... for most formats. Most of the inquiries I've received were for Ultra Large Formats where the cost of available optics (multiple $K) starts to approach the cost of a new design effort (which can be about $8k - $10k and go up from there). Of course, the inquiries usually cease when they see an actual quote. But, compared to the optics from a hobby like astrophotography or a modern really fast super-zoom lens (and especially that 1600mm f/5.6 Leica), the price isn't too bad.

- Jason

I question coming out of left field: Given the fact that some telescope makers grind their own lenses and mirrors, would it be out of the question to consider a similar model for this project, perhaps in the form of a two- or three-track option, plans only, parts kit, or complete product? I can see many roadblocks in the way of this idea, but I thought I would put it on the table for discussion.

 

[Nodda Duma]

Well yeah.. that’s what the optical prescription tells you: everything you need to know to make the lenses and where they are held with respect to each other. Then just make the mechanicals.

The real barrier is the cost if you were to get a kit with premade lenses. If you DIY the lenses the material is still fairly expensive, but it’s the time and know-how to grind and polish the optics and making the mechamicals which becomes the largest obstacle.

Keep in mind a telescope only requires one, maybe two surfaces to be ground and polished. A petzval requires 8 surfaces to be ground and polished, plus control of the thickness of the lens elements.

I encourage people to go for it, but understand what you’re getting into. In a fully funded professional design effort, a lens still requires at least 2 months of work out of a lens designer and a mechanical engineer (plus the optical and machine shop).

 

[RobertRedd]

Good suggestion. I don't want to reinvent the wheel Re : shutter design.

i for one DO wish someone would reinvent the wheel!