Ross London CdeV No. 2 Your thoughts Please?

**Daniel Unkefer** · 2-Jan-2019, 06:30

Thank You Steven!

Not being convertible is not a deal breaker for me. I have wanted this lens (for a while now) so that I can make more unique images with it, versus my plethora of 60s-70s (and very modern lenses). I am enjoying just looking at the ground glass with this one

Off to my local LF parts sources in my quest for a matching mounting flange, and maybe a missing brass screw that holds the knob against the barrel.

Soon I will shoot some test film and go from there.

**jhonsnicker** · 4-Jan-2019, 07:09

Originally Posted by Two23

When it arrives, see if it's a convertible Petzval. To do that, unscrew the front lens group and unscrew the hood. Unscrew the rear lens group. Turn the front group backwards and see if it will screw into the rear of the tube. If it does, it's a convertible lens. It becomes an achromatic doublet landscape lens. Focus it on something far away, then measure the distance from the middle of the lens to the ground glass. (It will be a longer focus than when all four elements were used.) Using a micrometer or something, measure the diameter of the diaphragm in the middle of the lens. Divide length by diameter and you have the new aperture value. I would write that down on the back of the lens board so you don't forget. It will be fairly close to the Petzval. If the Petzval configuration is fl=6 inches & f4, the AC doublet should be something like fl=9 inches and f6.3, or something in that ball park.

Kent in SD

Where did you find that? It's really unique, love it dude.
Send me the link to approach on it.

**jhonsnicker** · 4-Jan-2019, 07:17

Originally Posted by Daniel Unkefer

New Petzval Lens on Std Makiflex by Nokton48, on Flickr

OK It's here! Viewing through it, I absolutely love it! Surprisingly sharp on the glass. Shown on Makiflex Standard Body, lens focused on infinity target. I am so glad I took a chance on getting this one.

Later today, I removed the glass elements, nothing is marked anywhere. The central stop looks like it's much later to me, and rather homemade. Made of silver metal and coated with candle soot. I removed that rather easily from inside the barrel, and now I should have an F3.0 or F3.5 lens. Without the central stop, the lens is sharp in the center, and rather swirly at the edges as I have seen in so many Petzval examples.

Now I need to find a proper flange and clean it a bit more. I am super pleased.

You really did amazing, how do you feel know?
on the other way i can't explained my feelings.

**Daniel Unkefer** · 4-Jan-2019, 07:29

Originally Posted by jhonsnicker

You really did amazing, how do you feel know?
on the other way i can't explained my feelings.

I feel very good about this new purchase. I really do think this one is super cool.

I have had no luck getting a flange from Midwest Photo, I stopped in and JimmyA tells me he sold all his stash of hundreds and hundreds and hundreds of flanges and unbelievable stash of LF lens parts. What a bummer. An incredible resource in now GONE. On the other hand, he told me who bought all the goodies and I do stay in contact with this person..............

But, I have contacted an old friend, who collects old brass lenses. We are meeting Sunday and he is bringing a baggie of flanges that are close to 79.5mm, which is what I need. Jimmy A measured it for me with digital calipers, it's 79.5mm. Flanges are difficult, my collector friend says they were sometimes one-off specific to a given lens. BTW he says he just made a giant brass lens purchase, that nearly doubled his collection of brass lenses. And believe he has a MAJOR collection. So a great time to hook up with him and have lunch

I'm now in retirement mode (four days now) and soon I will get going with all these projects. Got a honey do list to work thorough but I am getting there!

I know I am going to enjoy using this Petzval. I have no regrets. And there are many ways to mount a lens to a board, when you don't have a flange. We will see on Sunday when I meet with my friend.

Life is good

**goamules** · 4-Jan-2019, 07:53

The only flanges that I've had luck matching to a lens are British. The TTH were patented, and the Dallmeyers were standardized. Out of hundreds of tries, I've only gotten a couple more that kind of, sorta fit a lens that had the flange missing. Even had a machinist make a flange for a big Cooke, but it didn't fit. I'd find an alternate method. I often just make a snug hole in the lensboard, then put a rubber hose clamp on the rear of the barrel, to hold it against lens thread rim, at the front.

**Two23** · 4-Jan-2019, 08:02

I have flanges made for my best lenses, and mostly those come from SK Grimes.

Kent in SD

**Daniel Unkefer** · 4-Jan-2019, 08:12

SK Grimes is a very real possibility. May I ask approx cost and time? JimmyA said they would need the lens (of course!).

My collector friend says he has screwed brass lenses in a soft aluninum plate, and then mounted the plate. And I guess there is always my friend JB Weld but that is a absolute last resort.

So I have few cards yet to play on this deal.

Maybe I will luck out Sunday. Or maybe this other Guy will let me look through all his flanges.

**Two23** · 4-Jan-2019, 09:50

I have wondered if a light duty substitute would be to drill a hole into a lens board very slightly smaller, grease the brass threads well, and then epoxy in place. For small Petvals on thin technika boards I've tightly wound tape around the threads protruding through the rear.

Kent in SD

**Daniel Unkefer** · 4-Jan-2019, 10:16

Light Duty Petzval Mounting Plaubel Board by Nokton48, on Flickr

I found this Plaubel board, which very tightly friction fits the main tube of the Petzval. (Had to remove the rear cell group). Screw the rear group back in, and I'm in business. This will do while I investigate options for a flange.