i know that people have had issues with the improper assembly of these petzvals so i got to thinking about this Darlot that i bought. the guy i bought it from thought it was for a ship & told me the rear lens had two lenses that were divided by a ring. the only way he would have known this is that he would have had to take it apart. i needed to clean it anyway so i took the rear elements apart and it appears that this cat that i bought it from had it assembled backwards and then some. i cleaned....didn’t break it...and re-assembled it per the petzval spec on this page.http://images.google.com/imgres?img...nw=114&prev=/images?q=petzval&um=1&hl=en&sa=N
now as i look through the lens it is considerably more clear in the center. there is still focus fall off due to the petzval design however the center is a little more sharp....in fact a lot more sharp in the center.
i will run some film tests to see where i am at.
steve

Hey Folks,
Well the lens adjustments appear to have worked. The center of the test image on the lower right is much more defined.
I went out to shoot the petzval but still need to get an ND filter and maybe slower film. i found that when i quick fire the packard shutter I have too much vibration causing blur. Exposure was there but blur was created by the quick snap. I found that opening the shutter and exposing for a second or two eliminated that issue. I will be looking at the Cokin system which I believe Andrew uses.
Steve

Do most of the people here use their lenses for wet plate work, or regular B&W film (or a combo of both)?

I've been looking at the collodion work posted and the itch just won't go away. However, living in an igloo like I do, I'm not sure how to get started on learning this process.

Colin: Regular.
I live in Denmark, Europe, and here we have a VERY strickt control on who is allowed to but raw chemicals....

Just to get Potassium Dichromate, I needed a police permit...

Wet Plate is (along with carbon printing) on the very top of techniques I would LOVE to do...

But I fear the regulations will restrict me....

(Maybe one could seek photographic asylum in the States?)

A photographic refugee, seeking asylum on artistic grounds. I like that concept!

For now I'm shooting film, but will start wet plate in early 2009. I know a lot of wet platers are 100%, but at this point I don't see giving up film. There's a good amount of information out on the web for starting on collodion, but I still think it's necessary to take a workshop or get some personal instruction. The Silver Sunbeam is one good online reference book.

http://albumen.stanford.edu/library/monographs/sunbeam/toc.html

barry..
yes - as long as one knows what that strange mesurements means....

grains - fluid ounzes - fahrenheit - "spec. grav., 1.843 .." and so on...

sigh...

Steve-- That's a great point about checking to make sure your petzval is assembled correctly. I bought a Darlot and was disappointed to find a single rear element and what I thought was only a cemented doublet up front. It took some very wild and swirly images, so i just figured it was another design. One day I removed the rear element and found a retaining ring and a spacer ring so I thought--ok, somebody broke one of the elements. A few days after that I was just falling asleep when a thought to check the front group struck me. I got up, unscrewed the front group and discovered that the missing rear element was sandwiched next to the cemented doublet! I reassembled the lens correctly and it got a lot sharper and some of the wildness went away. I may yet reassemble it incorrectly again because I liked the effect.

One thing to keep in mind is that the air spaced group can be reversed depending on the design. Some lens makers even produced Petzvals with both variations. Dallmeyer introduced the reversed group with the negative flint glass element behind the positive crown glass element. I've also noticed in some projection lenses that the air-spaced group is placed in front. So there are some variations within the Petzval family.

Barry, Thanks for the info, i am glad to see that i am not the only one who loses sleep thinking about this stuff. My wife says I am obsessed and I say....so be it.
Do you know of any sites that specifically talk about the different variations of the petzval assembly and the results from those variations? I am sure that the fellow APUG members have more knowledge than most and I am not sure how much more I need, i think just getting out to shoot more would be best.
Steve

I probably shouldn't assume that everyone knows this link, but it's excellent.

http://www.antiquecameras.net/petzvallens.html

I concur with what Barry says. The petzval area of this site gives really good insight into the history of these wonderful lenses, and also a really clear diagram on how the lens elements are supposed to be oriented.

I uploaded four images from my ongoing Memory Series. Since my main computer is on the fritz, scanning has been a little slow. The project is going well and I'm planning to have a show in late spring.

http://www.apug.org/gallery/showphoto.php?photo=40073&limit=2
http://www.apug.org/gallery/showphoto.php?photo=40074&limit=2
http://www.apug.org/gallery/showphoto.php?photo=40075&limit=2
http://www.apug.org/gallery/showphoto.php?photo=40076&limit=2

Somebody should take a look at this!!! http://cgi.ebay.ca/SALESMAN-SAMPLE-...3286.c0.m14&_trkparms=66:2|65:8|39:1|240:1318

And this.... http://cgi.ebay.ca/VERY-RARE-DUBRON...3286.c0.m14&_trkparms=66:2|65:8|39:1|240:1318

That box looks fun, although a few of those lenses may be missing the rear elements--it's hard to tell. Looks like it would cover a wide range of focal lengths. Naturally, no flanges--*sigh*. I like that Dubroni--looks like a nice Petzval with waterhouse stop and it's a 9x12 lens, so it'll cover 4x5--probably with a bit of swirl.

AARRGGH! Outbid...again! It seems official that these lenses aren't a nice little secret anymore. The prices are getting insane! Yoiks...at this rate it'll be cheaper to build my own time machine and go back to buy one.

Ouchm, that Dubroni just went for $380! It looks uncannily like a Darlot. Could be rebadged by them. Mine was not as expensive and was a real darlot to boot. Albeit without the waterhouse stop slot.

Yep, outbid on that one too. Seriously...almost US$400?!?? Oy vey.

I'd much, MUCH rather buy through APUG...and Andrew, images such as yours and Eddie's are -- despite my venting -- still inspiring!

The Lens Vade Mecum explains that Dubroni is an anagram of Bourdin--the maker. Bourdin made wet plate outfits and sourced the lenses from other makers--so who knows, it might be a Darlot. Colin, the lens I mentioned was shipped to me today and I have a feeling it's going to be "the one" for you.

Thanks, Barry...fingers crossed!

Anyone know anything about this Gundlach Optical 6" lens? http://cgi.ebay.com/RARE-Old-GUNDLA...photoQQcmdZViewItemQQ_trksidZp1742.m153.l1262 Looks like it might be a modified petzval similar to the B&L's I have, but am not sure.

I've been doing some research on projection lenses and there were several manufacturers watching each other very closely. I believe the Radiant is a second generation modified Petzval that would be Gundlach's equivalent to the B&L Cinephor II. At some point, most manufacturers switched to a six element (non-Petzval) design that was fast and highly corrected. For B&L, I think the switch came during the production of their Super Cinephor line. It looks like early Super Cinephors were still Petzval designs, but most of the lenses were the newer six element design. I have a 6" Gundlach (see pic) that preceeded the Radiant--it's a big fat classic Petzval and very large for a 6" lens. I think they were trying to find designs that would allow fast, but smaller lenses.

I just unearthed a Voigtlander 5A no.25851 lens from storage. It looks to be about 12" f/3.8 and maybe from around 1880. I tried looking up some more info from Dan's Petzval pages, but it looks like AOL has shut down all members' pages for some reason. Has he found another host or does anyone know of other reasources to dig up info on this lens? cameraeccentric.com and the vade mecum weren't of much help. Thanks. Joe

Joe, I found this on Google:-

http://www.vintagephoto.tv/voigtlens.shtml

and this at:-

http://www.allenrumme.com/lensdb/Portrait.html
Seems like the 5A is actually 13" focal length and covers 10x12

Scott's Photographica Collection
Voigtlander & Sohn
Portrait-Euryscop III No. 5A Lens


This large antique Voigtlander brass portrait lens measures approximately 7 3/8 inches x 5 inches, or 185 x 120mm. The original mounting flange is included. The brass has not been polished and has its original patina. The lens hood is not perfectly round, but it is not badly dented either. Although the lens could be easily restored, I don't think this is necessary.

The lens is slotted for Waterhouse stops, but none are included. The serial number is 36851, dating the lens to 1889. The focal length is approximately 14 inches or 350mm. The glass is in excellent, clear condition with just a few minor cleaning marks to the front and rear elements. The lens projects a brilliant and clear image on an 8x10 inch camera. Coverage appears to be greater than 8x10 inches.

After playing with the 6" Darlot some more this weekend, I stumbled across this website :-

http://www.lungov.com/wagner/c/090c.html

What is interesting is the history of the original Darlot Cone Centraliseur variant. Apparently, if you remove the front element and place the rear group in it's place reversed, you get a landscape lens hence the phrase Vis Paysage for landscape, and Vis portrait for portrait written on some of them. Similarly, the front element can go into the back reversed and becomes a portrait lens!!!

As a test, I did the swap with my Darlot 6" and was very suprised it actually works on my lantern lens. You need a lot of bellows extension, but it covers 4x5 really easily (no vignetting) with no really swirly fall off, but more of a creamy/dreamy bokeh. Could be a nice pictorial option for when swirlies are not desired!!! Like I said, it takes quite a bit of bellows, but my Chamonix handled it okay. I am not sure of the effective focal length, but it was nearly at full draw even at infinity. Just thought I'd share.

These things continue to surprise me!!