separation anxiety

[Robert Oliver]

Why did you post the question if you didn't want people's opinion. Focal Point can fix it, but not without risk or cost.

I think what everyone is saying is why not waste (test) a shot on a sheet of film to see if the quality loss is noticeable to you. If it is unacceptable fix it. If not, use the saved money for more film. This can be done with a textured wall to see what happens at the edges.

I personally don't mind a SLIGHT amount of darkening or fuzziness around the outside edges of an image, it helps bring the viewers eye into the center of your frame. I usually burn in the corners anyway.

I don't think it's a 'ticking time bomb'.... how long has it taken for the separation to cover this much of your lens?

Sounds to me like you are stressing out about what makes using these vintage lenses so unique and fun to use.... uniqueness. These lenses each have a unique signature. If you want perfect, buy a new modern lens.

[eddie]

NO NO NO---you guys don't have any idea...

---I can make anything DO anything I want with sufficient effort......

eeeerrrr? okay? so it would not matter the tool then?.......

I was curious to see---not trying to DO anything. I play at this--

fair enough.

an entertaining thread for sure. thanks for the chuckles.

[eddie]

Sounds to me like you are stressing out about what makes using these vintage lenses so unique and fun to use.... uniqueness. These lenses each have a unique signature. If you want perfect, buy a new modern lens.

+1

[johnielvis]

totally agree--I do try to get new/like new for that reason

and when I buy well used/old I buy what I think is 100% functional (these days---I haave bought fixer uppers in the past and that phase is on hiatus)--I was mistaken is all--I screwed up and didn't look closely enough -- thought it was 100% but when I finally got it I found it wasn't---it was my fault--I didn't look closely or ask questions--but still wanted to make it work...you know....I will buy what I think works-----I am through with the junk/projects/fixer-uppers/not100% stuff...

I just wanted to MAKE it work...see...the way I WANTED it to work...and it just wasn't in the cards that's all. I'll have to wait for another one to play with another day.....

[BarryS]

I'm curious--what was the lens anyway?

[johnielvis]

I must remain silent on specific lens info for now...sorry...

[GSX4]

Hang on a minute.... I never said ANYTHING about Focal Point toasting my lens.... It's a long story, and John at Focal Point is a professional... He never made any bones about the risks involved with fixing 150 plus year old lenses!!!

Long story short, the Dallmeyer 3b had a major 3/8" seperation/yellowing at the edge, and issues even further inside that were just starting that would eventually have led to image degradation. I had to do something.... I worked with the seller who was willing to take the lens back, and they were also good enough to meet me halfway with the repair costs... In hindsight, I'd never do that again. I'd return it. It was me taking all the risk... cost of a lens, additional repair cost, and nothing but a paperweight if it went tits up. At any rate, I rolled the dice, and off it went to Focal Point.

I get an email just after it arrived, and John said, it's an older lens where the front doublet has been rolled into its mount from the back. It's unlike the darlot's or other lenses that simply unscrew from their mounts. The rolled over edge needs to be carefully pryed back while holding the doublet in a lathe chuck!! There is a risk of breakage in this step and FP told me this could happen. They were successfully able to roll open the lip without breakage... Then comes the actual seperation of the doublet. They use a small oven to bring the lenses slowly up to around 300 deg f to melt the balsam, separate it, and let it cool to avoid cracking. Again, breakage can occur here too. It separated fine, but..... during the heating, one surface of the crown glass glazed over, and also to a degree on the edge on the other side of it. As I understand it, it can be caused by having 150 old VERY soft glass.

Again, John said he could polish it out, and the 2 lenses he has had that oxidized on him before have been fine after polishing. He said it should work, but does not mean that they could necessarily do that to my lens, but at this point I have paper weight. So we went ahead with the polishing. I was told it's a surface treatment only and would not impact the lens design/optical parameters at all! So it took 3 weeks to hear. One side is done with no issues, and was assured that John thinks we are going to be successful and told me to hang in there.. The reason it takes so long is the set up time and testing that the polishing was good. It's mounted, polished, dismounted, cleaned, checked, re-mounted and very tedious. So one side down, and I am hopeful the next side goes as good. Then we are on the home stretch.

Many will chime in saying that why didn't they use Xylene, or acetone and heat is BAD etc..etc... Focal Point came highly recommended, and I believe they will make it right. However, they are doing CYA about the very real potential for breakage of these older lenses.... I trust them and appreciate the up front nature of the way they do business.
Am I concerned about my lens... I sure am.... It cost me a kidney, and a spleen in repairs, but I am hopeful it will be restored and will NEVER be a problem again. No matter what the lens is, it is a gamble, and anyone who attempts these steps themselves may get lucky especially if you use xylene/acetone to separate the lens. In this instance, I did not have the tooling to open the rolled in lens, and it would have cost me minimally more to have them do all of it, so why not I thought?? At any rate, it is what it is... Focal Point has been totally professional so far. I would have likely made a pigs ear of it trying it myself. You pays your money, you makes your choice...End of Story.... Will update this thread on the overall outcome. At this stage it's looking good!

[Steven Tribe]

Sorry to hear about your problems, Andrew.

Turning the brass lip back on a lathe is the only way to do it! This is exactly the method Dallmeyer used to turn down the lip in 18xx. Many makers used this system(quick, cheap and reliable in skilled hands) for achromats , especially RRs - they were thinking of decades of use - not centuries!

The only way to polish a lens is to make a 3 dimensional tool which has the exactly the form of surface to be worked. Two sides of a lens means two special made tools are usually necessary! I don't know whether modern numerically controlled machines could produce these from the precise radius of the original surface. I know that this seems a lot of work for "just" polishing but there is tendency to remove too much glass at the edges without a convex/concave tool.

[GSX4]

Steven, that is why it is taking so long. They are being VERY diligent about removing too much material. I had a friend who has an old Leica Summitar lens fixed there and, polished/re-coated. Granted, those lenses were not anywhere near as old, but the coatings of the day were VERY soft. The machine that is used to mount the lens for polishing will scratch the older softer coatings, so BOTH sides needed to be polished out before coating. His lens turned out in superb shape, so I don't doubt Focal Point knows what they are doing... I guess I'll just have to wait and see..... keep my fingers crossed that I don't have a paper weight, and I've learned VERY expensive lesson about lens buying....

[johnielvis]

yeah--mee too!!!!

one thing for sure....if they don't outright say the glass is clear, it ain't--you must ask.

AND...just because SOME flaws are pointed out, that don't mean that ALL the flaws have been pointed out!!!!! you MUST ask the questions and assume nothing!!!

just like cars---if they don't mention the milage--it's very high
if they don't mention the price---it's high
if they don't mention the recent exhaust work, the muffler is gone
etc