Hawkeye Portrait f/4 Diffusing Focus

[cyberjunkie]

I think i'll find all the "old brass" fans on this forum, as the other place is currently off-line.
Now, let's go with my question:
i found the lens in subject on the big auction site, it was USA-only, but fortunately i was allowed to bid, and unexpectedly i won the item.
Probably the price didn't get too high because of the coverage. The other example that got recently sold on the bay scored almost twice, but it was a No.2 size (full plate). Other than that, the Web turned out very little informations. Of course the brand is just a reseller, but i couldn't find any reliable info. The diaphragm ring is fashioned like an old B&L one, but i found no pictures of B&L lenses with the same appearance. Just a guess, i just made a quick image search for "B&L Stigmar" but i found none.
Here is what's engraved in the lens barrel:
Portrait Hawkeye f-4
Diffusing Focus
Series A
No.1
5x8
Robert Dempster Sole Agency, Omaha, Neb

Two reference marks can be seen at the back of the lens, so probably the spacing between the two back glasses should be adjustable. I forgot to ask if the diaphragm leaves are still there. Not a real deal-breaker, though, as i suppose that the lens would show its best wide open.

Any clue about the lens maker? Anybody owning the same lens?

have fun

CJ

 

[luvcameras]

Hi

This is the same lens as the "Eastman Portrait" lens which is also F 4 in Series A and F 5.5 in Series B.

Not sure if Easmtan (Kodak) made these or had B&L make them.

Dan

 

[cyberjunkie]

Thanks a lot!
The word "Hawkeye" smelled of Eastman Kodak... I did a quick search but found nothing specific, just a lot of stuff about Eastman MF folding cameras.
The build looks B&L, though. At least from a few examples of the same vintage i have seen on the Web.
Living in EU, i have grown accustomed to Schneiders, Rodestocks, Voigtlanders, and the like. Some of them are quite overpriced these days, and i regret with all my heart all the missed chances i had, when an Apo Lanthar or a Planar were still affordable.
BTW, the catalog page you posted bears no reference to a variable diffusion adjustment. The word "Diffusing Focus" are clearly engraved on the barrel, and that translates to "soft focus" in plain language. So it should either be a "soft focus" lens, or a Petzval with variable diffusion adjustment (a la "Dallmeyer Patent Portrait"). The shape/size of the lens made me think it belongs to the latter type.

have fun

CJ

 

[cyberjunkie]

Portrait Hawkeye restoration

Got the lens.
First one interesting information:
the lens was actually made by Bausch & Lomb (as i suspected), and was sold as B&L Cephaloscope.
There are very little information about Cephaloscopes, i found that they were made in 14", 16" and 19" focal lengths.

The lens arrived in not-so-good conditions, but i have the hope to recover its full functionality.
First thing, what looks like a metal "cap" is actually a can, probably a very old one. Maybe a bean can
Unfortunately the lens came with no shade, and no flange. I was afraid that the diaphragm leaves were lost as well... more on that later.
Probably the lens was left unused for a very long time, it came with a LOT of oxidization, and all the threads were stuck.
The only good one was the softness control (that has no stop, so it can be unscrewed as much as you like, until the back cell comes loose!).
There are two (very noticeable) dings on both front and back cell rims. Not so extreme to be unrepairable, in my opinion. Fortunately the "cap can" was on when the lens got knocked, so it protected the front ring from being badly bent.
There were two bad news: the second cell (from the back) was stuck, as was the diaphragm ring. The small screws that retain the diaphragm ring assembly were literally covered in greenish oxide, that was probably leaked from the innards of the diaphragm housing long time ago.
I could not see the diaphragm leaves, as the ring was stuck wide open. I could live with the iris stuck wide open, but i had to open the lens somehow: the inner back glass was very dirty, and the affected surface was inside!

When i tried to unscrew the inner back cell, i found that it was stuck hard. Even with a oil filter wrench, and with a rubber hammer, it took a lot of force, and many knockings... but i ended up unscrewing the barrel from just behind the diaphragm assembly!
No way to unlock the lens cell!!
At least i had access to the inner surfaces of front and inner back cell, and i could clean them well. Unfortunately the inner back glass is very bulbous, and i didn't place it on a soft cloth when i was hammering The paper i placed on the table was not enough to avoid any damage, but the scratching are close to invisible. My goofyness didn't get punished too hard, all in all i have been lucky.
Next step was the stuck diaphragm ring.
I used WD-40, "Svitol" penetrating oil, and "G-20" dry circuit cleaner.
NO WAY.
I tried to unscrew the small screws (those that were submerged in gunk and oxide). I could unscrew four of them, but three of them were stuck, and got damaged. It's a very soft brass, and my watchmaker's screwdriver set is not of the best quality. Another less learned!
Next step: drilling the three damaged screws and remove the diaphragm assembly cover. That would allow to spray some penetrating oil from the inside. All my efforts from the outside were unsuccessful. A lot of spraying and a lot of small rubber hammer knocks didn't make any difference at all. I suspect that the oxide is actually sealing the inside, the diaphragm leaves didn't get any oil on them.
Before any brute force attempt, i'd like to know which other way could be taken.
Now the lens is disassembled in three parts, so i could submerge the diaphragm in a cleaning fluid, without affecting the glasses.
Which one? I have some rectificated petrol (very close to the naphta fluid used for lighters), that i use for shutter cleaning, but i think that its action would be too light for what i'm trying to do.
The liquid should be safe for the diaphragm leaves, that look non-metallic (very thin, and not attracted by a magnetic screwdriver).
I am open to any advice.
Thanks

have fun

CJ

 

[Brett_Jurgens]

This is interesting, as I live in Omaha. I am guessing from the markings that the lens was possibly rebadged and sold out of Omaha? I would really like to see photos of the lens once fully restored and images that it makes.

Brett

 

[jimgalli]

Made by Bausch & Lomb 100+ years ago. It is a petzval of excellent quality.

 

[cyberjunkie]

Hi Jim.
Of course it's a Petzval, but the two back elements look reversed (vs. a conventional Petzval).
I don't have any Dallmeyer or Wollensak petzvals with adjustable softness, though i think to remember that they had a different layout too.
The No.1 was advertised for 5x8", so i guess that it would swirl a lot on 8x10", if not used at very close distance. What's your experience?

Did you ever attempt to free a stuck diaphragm ring?
If you did, which cleaner was used?
Thanks

cheers

CJ

 

[cyberjunkie]

I tried in many way: freezing the lens, gently hammering the diaphragm ring, applying more penetrating oil, but to no avail.
I think i'll try submerging the diaphragm with naphta and leaving it alone for some time. I have not much faith, though.
I don't know which fluid could be used, without damaging the diaphragm leaves.
I am waiting for your help, before i do something silly, just for the hurry to have it fixed as soon as possible.

CJ

 

[jimgalli]

This is what I use. It's got Xylene and leaves no residue. Won't harm the phenolic blades. GEt it at the Napa Auto Parts store. It's made to buff rubber before a patch goes on, but I use it for all my camera projects including shutter repair and also soaking joints that I want to unscrew.

I don't remember which is which on the rear group but seem to remember it only goes together one way.

I always put the thin glass at the back but I guess Dallmeyer reversed that.

 

[cyberjunkie]

Quick update.
After asking for some specialized advice (italian professional restoration forum), i choose to use a low-tech approach:
left the central part of the barrel, where the diaphragm mechanism is located, in a bath of sodium bicarbonate, raw salt and water, for about 24 hours.
Then i added a couple of spoons of vinegar, left a couple min. more, then i gave a small knock with a rubber hammer. The diaphragm ring came free!
There was still a lot of build-up of a white residue, probably coming from crystalized bicarbonate. I soaked with some naphta, and a lot of dirt got washed away: melted shellac, dirty lubricant residue, leftovers from the salt/bicarbonate/vinegar bath, the penetrating oil i applied, and whatever else...
After that everything was much better, but there was still some withe residue on diaphragm leaves, and the diaphragm ring (and the pins on the leaves) were working almost dry, with a tendence to get stuck. At one time i had three leaves that went out from their grooves. Fortunately i could re-insert the pins, but some lubrication was needed!
I applied one micro-drop of sewing machine oil to each pin, a very (very!) moderate amount of WD-40 to the innards of the diaphragm ring, and cleaned the white build-up on the leaves with a glass cleaning fluid.
Everything seems to work in an acceptable way now. I'd say that i had a fairly good success, without dismantling the diaphragm assembly.
If i had to completely dismantle the lens, i should have drilled the three damaged screws, and replaced them (very difficult here, with non-metric thread pitches).
I reassembled the lens, after cleaning again the glasses, but i still have to clean a lot of oxide from the brass barrel. I tried a specialized product, too soft for that level of oxidization. Before spending money on another commercial product, i'll try my luck with a mix of water/sodium bicarbonate and vinegar.
I think i'll repaint the back rings in a flat black, to avoid reflections.
I found a few pictures of the same lens, either marked Eastman, B&L or Burke & James. Some have a blackened back, some have it in non-painted brass...
The example i own had a black front ring (there are traces of the original enamel), but no traces of paint can be seen on the back of the lens. Still unsure if i should privilege originality, or correct the lens for best performance.
What do you think?

P.S.
I choose to delve into details because i hope that, sooner or later, somebody could be interested.
There are plenty of informations about history and technical specs of lenses, too little useful infos for those who, like me, love to follow the DIY route.
Fix something on your own is cheap, and highly rewarding (well... most of the times)
So i love to give some advice whenever i think that it could be useful to somebody


have fun


CJ