Understanding Allen Rumme's Lens Database

[Qeb]

Greetings all,

My name is Kevin and I'm doing research into ULF photography, specifically, I'm looking to building or buying a 16x20 camera that is capable to shoot tintype portraits (1:1).

I'm not sure where to start, so I've been reading and bookmarking as many websites as I can.

One thing I am looking at early on is lenses.

Concerning the database that was mentioned elsewhere, http://www.allenrumme.com/lensdb/DBIntro-1.html, I was wondering if someone could help explain,
Coverage Wide Open ,Coverage Stopped Down, Coverage (1:1) ?

I have a feeling what they mean, but maybe others could help me be certain.

Also, do I want to be looking in the process database or portrait. I'm finding more hits on ebay from the process database.
Maybe if it is allowed, I can post some ebay items for consideration purposes.



Any advice or opinions are very welcome in terms of easily attainable lenses for portraits (1:1 head shots but also able to shoot full body (environmental portraits)).
I'm not crazy rich, so not looking for top of the line lenses/shutters. Not looking for soft focus lenses but as sharp as possible with out spending a lot.
(Edit: I guess I'm looking for a lens around 400-600mm)

We used 4x5's in university, but briefly and all parts came in one large carry case, we never got too technical.

Thanks so much for reading this.
Have a lovely spring season and rest of your week!

Cheers,
Kevin

[Dan Fromm]

Kevin, Mr. Rumme built his list of lenses for his own reasons. He's explicit about them, read his introduction. His list is, like all such, incomplete and contains errors. I think you can get more and better information by using this site's resources. See, in particular, http://www.largeformatphotography.in...mainly)-lenses ("the list"). You'll have to do your own legwork if you do. I hope you find the effort rewarding.

To answer your questions, coverage wide open is the format (width x height or image circle's diameter) that a lens will cover at full aperture. Full aperture means with the diaphragm wide open, i.e., with the f/number's denominator as small as it will go. If you don't know what an f/number means, the list will direct you to books that explain.

Coverage stopped down is coverage at an unspecified aperture smaller than wide open. With modern lenses if often means f/16 or f/22, with ancient lenses it can mean a smaller aperture. Up to a point, the smaller the aperture the larger the IC. This because IC is defined in terms of the circle of "good enough" image quality. Some off-axis aberrations are sensitive to aperture and stopping down tames them. But stopping down increases diffraction's effects and at some point stopping down reduces image quality and the IC. At large apertures off-axis aberrations swamp diffraction, at small ones its the other way 'round. The list points to an optics tutorial that explains all this more fully.

Note that enlarging requires better image quality than does contact printing. Direct positive processes such as tintype are equivalent to contact printing. This is why there are interminable wrangles here between contact printers and folks who enlarge their negatives.

The image circle gets larger as magnification increases. At 1:1 (that's image the same size as the subject) the IC's diameter is twice as large as it is with the subject at infinity. Process lenses' ICs are often specified at 1:1 @ f/22 or f/32.

16x20's diagonal is a little larger than 25", 640 mm. You'll need a lens with an IC at least that large at your working magnification. The list points to rules of thumb for calculating IC given magnification and IC at infinity. You'll have to decide the magnifications you're going to work at before you can know the IC's (usually specified at infinity or 1:1) that candidate lenses must have.

Process lenses typically cover narrow angles.

Big lenses require big shutters. $$$. Think about roller blind shutters, including a mutilated Speed Graphic.

Good luck, have fun. And don't spend a penny on a lens until you've worked out what you need.

If you haven't read this http://www.largeformatphotography.in...-Tipping-Point discussion, read it now.

[Qeb]

Hello Dan Fromm,

Firstly, thanks for your reply!

Okay, I'm trying! haha, Been going over the pdf file and reading what you replied with.
I'm a little foggy right now, but I couldn't find the parts of the pdf you mentioned.
I first went through over the entire pdf, and now picking parts that stand out.

I'm reading what you wrote and re-reading. I'm getting parts and confused on the other parts hahah
Darn, I wish they taught us all of this in art school haha

I remember they were telling us not to stop all the way down, for image quality.

Does this chart then mean, at 60cm @f22 the image coverage/circle diameter is 41.48 cm?
https://imgur.com/a/E9xbq

I hope this isn't annoying, but could you tell me which chapters in the list/pdf to read? Since the list is in alphabetical order, it's a bit hard to navigate

Thanks again for your reply sir!
Have a good week!

[Qeb]

Hey Dan Fromm and others,

What do you think of these portraits in terms of the lens chosen? tl;dr: Rodenstock Sironar-N 480mm


http://www.tested.com/inventern/4567...ampaign=Buffer


For a 14x17 camera, the article says the equivalent for 35mm is 40mm. I know the obvious, that many like 85mm as a non-zoom portrait lens for different systems/platforms.
Do you like the slight distortion that exists relative to a longer lens?

In the : http://www.largeformatphotography.in...-Tipping-Point post, a person is recommending 450mm and 600mm.

Dan, I found both of those lenses on ebay! The list/pdf you told me to go over says the nikor M 450mm has a image circle of f9 at 420mm and at f22 440mm (10"x12").
Would this mean (considering what some people said on the tipping point post (above link), it would suit me well shooting 16x20?

And the Fuji C lens have a IC of 620mm. I guess I'm still confused a bit

Thanks so much Dan and everyone else who might chime in

Cheers,
Kevin

[Bernice Loui]

"The amount of detail on a 35mm film camera is estimated to have the equivalent digital information of a 20 megapixel image (dependent on film quality, speed, and lens). 4x5 inch large format film is estimated to contain 200 megapixels of data. Since a tintype is a direct positive process, the 4x5 tintypes Michael shot for us last year have about that much data--no consumer DSLR can capture its fidelity in its entirety. But the 14x17 inch tintypes that Michael can now shoot are 10 times the physical size of those 4x5s, meaning these are effectively gigapixel portrait photographs."


-Errr, no, just no. Overall image quality is not this simple. Reducing the entire eco-system down to pixel count is beyond excessive over simplification of what makes an expressive image.

Extremely difficult to judge any image for overall effect via the web due to the huge number of variables and factors that absolutely alter the original image -vs- what is displayed on each data to image conversion device.



Bernice

Hey Dan Fromm and others,

What do you think of these portraits in terms of the lens chosen? tl;dr: Rodenstock Sironar-N 480mm


http://www.tested.com/inventern/4567...ampaign=Buffer


Cheers,
Kevin

[Dan Fromm]

Kevin, you're asking questions that you should learn to answer for yourself. Buy a book. Read a book. Study it and think about what you've read. The list contains descriptions of the most-highly recommended books on LF photography.

And learn to follow directions. This list is a PDF with bookmarks. Its bookmarks serve as an index. They don't work with on-line pdf readers, the file has to be downloaded and read off-line. The link to it says so.

[Qeb]

Hey Bernice,
Thanks for your reply.
I remember in the first year of university, I was the only one who owned a DSLR and people were debating back then film was superior with out much data or knowledge to backup that claim.


Dan, hey thanks for your reply again.
Okay, I use foxit reader and yep, I was using the bookmarks/chapters tool bar on the left side.
I was just asking you to maybe tell me which bookmarks correlate to the parts you said I should learn from the list as I went through the entire list and didn't see what you said was there from your original post.

Okay, Dolphin Dan has helped me a bit here....

So, I want a lens that has a IC of 650mm minimum at the smallest aperture (to shoot 16x20 - because the hypotenuse is 650mm)

And since I want to do close in head shot portraits (wide open aperture because of wet colloidion sensitivity), I want to find a lens that will do a 1:1 shot while still covering 650mm.
But I also want a lens that can do wide portrait shots, so that means the lens must cover 650mm while focusing at infinity.

Does it make more sense then to get one lens for 1:1 head shots, and another lens for wide angle shots?
That's what I'm getting from the "pdf list's" links to IC data on lenses.

I'm I sort of understanding now? I'm I missing something?


Thanks again so much!!!
Have a nice Tuesday evening!
Cheers,
Kevin

[Joshua Dunn]

Kevin,

Where do you live? The reason I ask is aside from some of the technical concerns you have raised there is a whole host of issues just shooting ULF. You want to shoot tintypes which is a whole other set of problems/technical requirements. Have you shot wet plates before? I would try and see if there is any alternative process group near you that you can visit or join to mentor under. It's not a process that is easy to learn with just Google and YouTube. When I took on wet plate portraiture I was shooting on my 8x10. But I mentored under a really talented wet plate photographer which really improved my learning curve.

The larger you go the more expensive this will be on every front. Cameras, lenses chemistry etc. (unfortunately I speak from experience, I go big on everything). Is there a reason you want to go with 16x20? Is it because you want to show your subjects at life size?

-Joshua
www.joshuadunnphotography.com

[Pere Casals]

Some ULF recommended lenses

http://www.angusparkerphoto.com/blog...ndations-14x17

The 650mm is a bit short for 16x20 headshots. You will be too near of the subject if wanting to fill the frame with a head, so you will obtain a "nose job", but no problem if you want that... The 650 would be better for half body or even head and shoulders. For headshots consider 800 to 1200mm.

[Qeb]

Hello Joshua Dunn, I'm in Toronto Canada
Oh, great idea.... how would I search for a group?
I think I will look into taking a workshop in May.
Thanks so much for raising these concerns!
Well, I guess I would like to shoot in 16x20 because of my experiences from art school. Sometimes, not all the time, we were encouraged to print a bit larger. That's not to say smaller dimensions were discouraged....but depending on the subject and message/discussion 8x10 was often seen as being lazy not putting enough effort in presentation.
4x5 dimensions arn't to small, but I feel 16x20 will really pop and allow my future portrait subjects to happily display the final plate in their homes.
Oh, nice architecture photography Joshua.... you have a good eye and great technical skills!

Hey Pere Casals,
Thank you so much your advice and the link. I saw that link last week while binge researching, but I didn't think I needed lens much longer that 650mm.
But thanks, because now I have to think/research more!

Cheers!