14x17 Tessar Series IIb worth fixing?

[Dustyman]

I picked up Ansco studio camera yesterday and it came with a pretty ugly 14x17 Series IIb Tessar. Mostly it's the paint that is ugly... the writing on the front was barely legible because of the black plaint has chipped away. I had to inspect it by shining a light at an oblique angle to see the barely perceptible engraving which says "Baush & Lomb 14 x7 Tessar Series II b Pat Feb 24, 1903. The aperture scale is equally difficult to read, but it goes from f/6.3 -> 64.

The glass looks pretty good. Just some dirt specs. However there is one aperture leaf that is floating in there, and it bends if I try to sop down. The other blades seem to work well. I have to decide whether it is worth fixing for me.

I know this lens is known for it's massive coverage, especially stopped down. I shoot 8x10 portraiture so that isn't a real factor for me. The question I have has more to do with the rendering qualities of this lens. Can anyone share what characteristics this lens has? Is is it known to be sharp or soft, and at what apertures? Is it sharp centrally, but soft on the edges (with 8x10)? Is is known to be a good portrait lens? How does it handle highlights, for example. Finally, how does it transition to out of focus areas? Smooth and dreamy ...or otherwise?

Does anyone have any portraits they have done that can be shared?

If it is any way unique in its image rendering it may be worth it for me to have the aperture repaired.

Thank you

[LabRat]

It's worth a stab...

I have several large Tessars and like what they do on OOF and transitional areas better than Aero-Ektars on smaller cameras... Lower, but smoother contrast than more modern lenses that works well with longer toe B/W films... Great depth "modeling" that looks more than 2D due to large lens diameter...

As-is, put one on your old or new camera (with a clean GG), and poke around with it to view what's happening with it... Worse case would be to remove one iris blade if it's pivot is damaged, but often can be saved... Note that the blade is a plastic material that often snaps back down flat if pressure is removed... But the first thing to check is if front and rear element groups unscrew from barrel, as these sometimes will fuse on (difficult, not impossible to remove)...

I found a box of orphan/rescue lenses including a 12" Tessar that needed a lotta love, and like using them for my still life use...

Steve K

[Dustyman]

Thanks, Steve. That's exactly the kind of information I'm looking for.
I was able to unscrew the rear cell group and was able to remove the wayward blade. Not sure how to reinstall properly, so now there are 19 instead of 20 blades. Of course, the aperture is no longer perfectly round, but probably usable. The aperture ring turns, but mostly it gets stuck and really fights me. Any suggestions as how to get this to loosen up?

Bruce

It's worth a stab...

I have several large Tessars and like what they do on OOF and transitional areas better than Aero-Ektars on smaller cameras... Lower, but smoother contrast than more modern lenses that works well with longer toe B/W films... Great depth "modeling" that looks more than 2D due to large lens diameter...

As-is, put one on your old or new camera (with a clean GG), and poke around with it to view what's happening with it... Worse case would be to remove one iris blade if it's pivot is damaged, but often can be saved... Note that the blade is a plastic material that often snaps back down flat if pressure is removed... But the first thing to check is if front and rear element groups unscrew from barrel, as these sometimes will fuse on (difficult, not impossible to remove)...

I found a box of orphan/rescue lenses including a 12" Tessar that needed a lotta love, and like using them for my still life use...

Steve K

[Dan Fromm]

Years ago Bert Saunders sent me instructions for cleaning B&L Tessars' in barrel diaphragm mechanisms. Here's a link to it: https://1drv.ms/u/s!AggQfcczvHGNgkP3...PA1aA?e=yUaHiY

I've followed those directions for several lenses.

[LabRat]

Thanks, Steve. That's exactly the kind of information I'm looking for.
I was able to unscrew the rear cell group and was able to remove the wayward blade. Not sure how to reinstall properly, so now there are 19 instead of 20 blades. Of course, the aperture is no longer perfectly round, but probably usable. The aperture ring turns, but mostly it gets stuck and really fights me. Any suggestions as how to get this to loosen up?

Bruce

Get some acetone and silicone spray containing acetone... Put a little in a hypodermic syringe and put a couple of micro drops of acetone in the seam between the ring and body (not in the sector where there is a seam into the barrel... Repeat, turn ring several times, then the silicone into the hypo and turn, turn, turn (slowly)... This can soften up the old grease and the silicone smoothes it out to "reuse" old grease without teardown... Helps a little...

One problem with the old iris is the pivot holes start to bind the pivots on the blades causing the blades to bind and buckle, but I resorted to rubbing a little graphite into the holes with a toothpick, then q-tip and the pivots then turned freely again...

Good luck!!!

Steve K

[Steven Tribe]

This has a focal length of just under 20”.
This was sold as a process lens. The F.6.3 Tessars of all makes are the better lenses. Krauss of Paris made an awful lot of the metric version of this lens 50cm - there are always one or two on EBay in Europe.

[Dustyman]

Thanks Dan. This helps. Wish it went so far as to include re-installing the aperture blade : )

Years ago Bert Saunders sent me instructions for cleaning B&L Tessars' in barrel diaphragm mechanisms. Here's a link to it: https://1drv.ms/u/s!AggQfcczvHGNgkP3...PA1aA?e=yUaHiY

I've followed those directions for several lenses.

[Dustyman]

Thx Steve. The binding is probably what caused that one blade to buckle and ultimately pop out.
Do you know of any guidelines that walk through fixing this?

Get some acetone and silicone spray containing acetone... Put a little in a hypodermic syringe and put a couple of micro drops of acetone in the seam between the ring and body (not in the sector where there is a seam into the barrel... Repeat, turn ring several times, then the silicone into the hypo and turn, turn, turn (slowly)... This can soften up the old grease and the silicone smoothes it out to "reuse" old grease without teardown... Helps a little...

One problem with the old iris is the pivot holes start to bind the pivots on the blades causing the blades to bind and buckle, but I resorted to rubbing a little graphite into the holes with a toothpick, then q-tip and the pivots then turned freely again...

Good luck!!!

Steve K

[LabRat]

The last time I had a large Tessar apart was a few years ago, but the item I was working on had the major issue of most of it being fused together, and my task was mostly to get it apart... The iris and ring were frozen stiff and the element groups were stuck on the back and front... I could see where someone tried to remove front group with large pliers as there was a tiny trace of teeth marks on outside...)

Once apart managed to get aperture ring to turn a little, but noticed iris blades started to buckle... I had read somewhere how to remove ring and finally got it off, but it was not clear how to access iris assy, so had to attempt saving it while assembled... Noticed some blades were "lazy" and tended to buckle... It was not clear how to just remove entire iris, so had to take the dry lube path on the pivots...

Graphite and moly powders have a bad reputation in repair as they were usually misused by shooting a cloud of this fine abrasive into leaf shutters etc, but techs also know that used sparingly, it is a fine polish for dry metal to metal sliding of moving surfaces (like lapping on car valves)... It is chosen for limited uses where there is an intimate metal to metal moving surface where sticky oxides can build up and prevent free movement... So a tiny amount is applied right in the pivots, spread to the contact surfaces with a wood toothpick, then excess is cleaned up with a q-tip, sometimes followed by a micro drop of alcohol to penetrate... Once the ring has been cleaned and lubed, small rotations of the ring will cause slight movements of the pivots and will slowly free up...Don't turn the ring too much now to extremes, just rock it a little (about1/3 stop), then as it seems free, just a little more each time... You can tell if free as the blades will stay flat when that pivot is free... Repeat the pivot lube as necessary, and be very patient with them... (Do not try to oil them as this can add a sticky bond to them due to viscosity of lube...)

Replacing the popped out blade would be tricky without teardown, but since it's working now, I'd leave it alone, as it's not clear how to remove entire iris, and I seem to remember it looked difficult to close it up again... I have used lenses missing a damaged blade or two and they worked fine, but maybe if there's distant OOF highlights, their shape would not be perfectly round but close enough (and leave a "signature")...

Step at a time...

Steve K