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View Full Version : Revised article by David Karp: Introduction to Lenses for Large Format Cameras



QT Luong
20-Mar-2007, 01:49
The 2nd edition of David Karp's Introduction to Lenses for Large Format Cameras (http://www.largeformatphotography.info/lenses-primer/) has been posted. All constructive comments welcome here.

Greg Lockrey
20-Mar-2007, 02:37
Excellent....4.0! I have the page bookmarked for future reference and links. Well done David, thanks.;)

Jack Flesher
20-Mar-2007, 07:16
Great article!

My only comment is I would refer to short lenses as "short" just like you did for long lenses. I find newbies often get confused with the term "wideangle" as it is used in 35mm and medium format, versus the LF lens' stated angle of field. I would also probably then add a paragraph on lens angle of field and how it corresponds to image circle to further clarify the distinction.

Cheers,

James E Galvin
20-Mar-2007, 07:59
I second "good article"
A couple of minor issues:
The hole in the lensboard is sized for the shutter, not also the rear element.
A 300mm telephoto needs about 200mm bellows, not 270mm.
Jim

Gordon Moat
20-Mar-2007, 11:50
Nice article. I have noticed a few Congo lenses labelled as Yamasaki Optical. Perhaps that might be something to add onto the article.

Ciao!

Gordon Moat
A G Studio (http://www.allgstudio.com)

David Karp
20-Mar-2007, 22:19
Thanks for the comments. I will track this thread in the future if there is ever a third edition I will take them into account.

Ole Tjugen
20-Mar-2007, 22:43
Another "niggle":

The classic convertible lens is not the "Bausch & Lomb Protar", but the "Zeiss Protar Serie VII, also produced under license by B&L, Ross, and others".

Apart from that, well done indeed!

BrianShaw
21-Mar-2007, 09:00
Nice!

Eric Woodbury
21-Mar-2007, 10:29
Nice article. Keep up the good work.

Edits: The pic of the "72mm" lens is really a 110mm lens. And, Rodenstock also discontinued the Apo Sironar W lenses, of which the 150mm is a must lens for 5x7.

Alex Wei
20-Jul-2007, 15:50
Nice read for me. Thanks.

A question, does any LF shutter has a self-timer? and also, you didn't mention polaroid shutter in the article.

Alex W.

David A. Goldfarb
20-Jul-2007, 16:58
Nice read for me. Thanks.

A question, does any LF shutter has a self-timer?

Alex W.

Some Synchro-Compur shutters have self timers. Be sure the shutter is in good repair before trying it, because old ones will get stuck easily.

Some have a "V" setting for the self timer, in addition to "X" for electronic flash and "M" for flashbulbs. These are easy to identify.

Some have a button near the shutter cocking lever, and to use it, you have to slide the button out of the way to move the lever to the self-timer position. These are harder to identify from a picture, because some shutters have a similar-looking button to open the shutter for focusing.

Older 90/6.8 Angulons and 90/8 Super-Angulons often have this type of shutter. It's kind of a long timer--about 15 sec.--so people can get a little uncomfortable waiting around for it. That's me with the baby--

http://www.echonyc.com/~goldfarb/who/22.jpg

Bill_1856
20-Jul-2007, 19:18
The 2nd edition of David Karp's Introduction to Lenses for Large Format Cameras (http://www.largeformatphotography.info/lenses-primer/) has been posted. All constructive comments welcome here.

Nicely done as a good place to start.

Dan Fromm
21-Jul-2007, 07:12
The discussion of telephoto lenses seems a little confused. David wrote "The second key difference is the location of the lens's optical center, also called its nodal point. Most normal lenses have nodal points located roughly in the center of the lens, near the shutter. In contrast, the optical center of a telephoto is located in front of the lens."

This is wrong. A lens has two nodal points, and the one David is talking about is the rear nodal point. The idea of "optical center" has been floating around but I've never seen it defined and it isn't used in any of my "optics for complete idiots" books.

The discussion on manufacturers focuses on ones who've been active fairly recently. This is nice, but since lenses don't wear out an older (and less expensive) lens can still be a good alternative to the relatively modern ones David mentions.

The bibliography is too short, and for my money Kinglake is a bit, um, idiosyncratic. And it doesn't address the unfortunate fact that lens design has little to do with performance. Coverage, yes, image quality, no.

More later,

Dan

Capocheny
21-Jul-2007, 15:17
Aside from the few inconsistencies... well done, Dave!

Thanks for the posting QT. :)

Cheers

Alex Wei
23-Jul-2007, 21:19
Older 90/6.8 Angulons and 90/8 Super-Angulons often have this type of shutter. It's kind of a long timer--about 15 sec.--so people can get a little uncomfortable waiting around for it. That's me with the baby--


David, thank you. I just found the 'V" on my super angulon. Glad to see the baby getting a little bit bigger now. Wish you the best.

Alex W.

Ken Schroeder
24-Jul-2007, 17:07
David,
I applaud your effort. In my opinion, your work is worthy of a revision. I mean this in a constructive, positive manner. I printed out your article this morning to read it before suggesting it to my nephew who is just starting with 4x5. (All 26 pages.)

In my opinion, you are trying to cover too much territory. For a beginner, I would suggest leaving out (or perhaps placing in appendices) the sections on shutters other than 0 or 1 size Copal; lenses longer than 210 or shorter than 135; convertible and barrel lenses and much of the comparisons of the big three or four brands.

I believe a beginner should start with a six element 210 lens and maybe a similar 135, both in Copal shutters. No siege mortar lenses in #3 shutters or packard shutters. No difficult to view and focus extreme wide angle lenses. Even if the student routinely uses very wide lenses with smaller formats, the 210 is a great teacher. Learn the format and the discipline of large format, and than add whatever lenses one likes.

I like the section on lensboards and mounting shutters.

I believe you have the heart of a fine article. I would like to see it condensed to about five pages at most.

I have no doubt others will disagree with some or all of what I have stated. I submit this in the spirit of constructive encouragement for a worthy project and wish you well.

Ken

rippo
29-Oct-2007, 09:36
David,

In my opinion, you are trying to cover too much territory. For a beginner, I would suggest leaving out (or perhaps placing in appendices) the sections on shutters other than 0 or 1 size Copal; lenses longer than 210 or shorter than 135; convertible and barrel lenses and much of the comparisons of the big three or four brands.


Ken

I think some improved organization might be beneficial. I find much the same with my office. However I still function when it's in disarray. Splitting the article into different sections might make it clearer. But as a relative beginner to LF, and a voracious reader, I'm just going to read those other sections anyway. It seems somewhat arbitrary to assume the beginner is going to like being told what *not* to think about. I'd want to know that there were other lenses besides the 210 that came with my monorail, so I can start seeing the possibilities. And also know the pitfalls, so that I don't rush out and buy every lens size under the sun (and in this dream, money grows on trees and I have my very own pony.).

So sure, organize the article if it works better. What I'd *really* like is more information on just about everything, and I'll tidy it up in my mind if I have to.

Barry Wilkinson
11-Aug-2009, 07:15
Thanks David, interesting reading.

BTW: The Wisner link does not work (unsurprisingly)

Bill_1856
11-Aug-2009, 09:37
Well done. Thanks.

FilmIsNotDead
11-Aug-2009, 10:30
Two year old thread but yes, well done :-)

C.T. Greene
16-Feb-2011, 00:24
I think some improved organization might be beneficial. I find much the same with my office. However I still function when it's in disarray. Splitting the article into different sections might make it clearer. But as a relative beginner to LF, and a voracious reader, I'm just going to read those other sections anyway. It seems somewhat arbitrary to assume the beginner is going to like being told what *not* to think about. I'd want to know that there were other lenses besides the 210 that came with my monorail, so I can start seeing the possibilities. And also know the pitfalls, so that I don't rush out and buy every lens size under the sun (and in this dream, money grows on trees and I have my very own pony.).

So sure, organize the article if it works better. What I'd *really* like is more information on just about everything, and I'll tidy it up in my mind if I have to.

I agree whole heartedly with his sentiments, found it informative & interesting; saving it to file (mht) for closer reading. I have been giving longer lens more than passing glances so the section on barrel & shutters is an excellent addition worthy of inclusion.