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Kodak Ektar coatings vs Wollensak Optar coatings
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dstoenner



Joined: 03 Jun 2016
Posts: 29
Location: North Carolina

PostPosted: Wed Sep 07, 2016 4:32 pm    Post subject: Kodak Ektar coatings vs Wollensak Optar coatings Reply with quote

Hi,

Since I am getting back into medium/large format photography after a 20 year break I don't remember if I had noticed this before or not. I have purchased a few lenses off of ebay. What I have noticed is that almost to a lens, the Ektars have been free of cleaning marks but the Optars all seem to have some to a LOT of cleaning marks on the front element.

So does anybody concur with that observation? Is it because Kodak coatings are actually harder than Wollensak coatings? I don't think that it is because people treated them differently.

As a byproduct of this question is about Optars with a lot of cleaning marks. How degraded in contrast and/or resolution are these lens that have a lot of cleaning marks?

Thanks in advance for any answers.

David
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45PSS



Joined: 28 Sep 2001
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PostPosted: Wed Sep 07, 2016 9:33 pm    Post subject: Reply with quote

I've seen my share of Ektars that looked like they had been cleaned with 1200 grit sand paper when viewed at a 45 angle to a bright light source but appeared clear when viewed straight on (90 angle).

As to performance, ask them.
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Dan Fromm



Joined: 14 May 2001
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PostPosted: Thu Sep 08, 2016 11:30 am    Post subject: Reply with quote

I have several Ektars with the classic "Cleaned with sandpaper" look too. They shoot badly, alas.

But I have few very ugly lenses that shoot well. Whether a lens with a scratched front shoots well seems to depend on the scratches and the lens' design.

As for performance, back in the days of the usenet that was, Richard Knoppow insisted vigorously that Wollensak's tessar type Raptars were less well-corrected for off-axis errors, coma in particular, than the equivalent tessar type Ektars. Because of this Raptars had to be stopped down two stops more to match Ektars' image quality towards the edges of the field.

FWIW, even though for years I regarded my 101/4.5 Ektar as the gold standard of normal lenses for 2x3, there's no reason not to use modern lenses on Graphics.
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dstoenner



Joined: 03 Jun 2016
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PostPosted: Fri Sep 09, 2016 12:30 am    Post subject: Reply with quote

Dan Fromm wrote:


FWIW, even though for years I regarded my 101/4.5 Ektar as the gold standard of normal lenses for 2x3, there's no reason not to use modern lenses on Graphics.


Dan,

I now have a 101 F4.5, 2 127's and a 152 Ektars. I also have a 150 F5.6 Caltar II-S. I just recently did a lens test of the 101 vs the 127 vs the Caltar 150. I shot all 3 at 200/F11, 100/F16 and 50/F22. The 127 Ektar and the 150 Caltar were sharp at all these apertures. I was looking at some small tree limbs in an upper corner. The 101 was not as sharp till F16. But it could be a small breeze blowing the branches. Overall I was very happy. Once I get a scanner I can do a little more accurate comparison between these 3 lens. the good news was that all 3 negatives of each lens showed very consistent negative density with in each lens and even across the different lens.

The 3 Optars I have are a 101, 135 and 162 (uncoated). The 101 is really clean on all surfaces. The 135 has only a few marks on the front element. These are all in the coating because you have to use a jewelers loupe at an oblique angle to see them. The 162 has no marks that i can tell because it is not coated. The last 2 of these lens are set up for my 4X5 crown which is in storage so till I have house to downsize to I cannot test those.

All, thanks for the input.

David
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Dan Fromm



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PostPosted: Fri Sep 09, 2016 10:14 am    Post subject: Reply with quote

Interesting that y'r 162 Optar isn't coated.

Optar is a Graflex brand, most Optars were made by Wollensak and sold by Wollensak as Raptars. I've always understood that Wollensak replaced the name Velostigmat with Raptar and started coating at the same time (sometime in 1946).

Why do you think y'r 162 Optar isn't coated?

What format did you shoot your lenses on? I ask because a 4" tessar type won't cover 4x5 so shooting one on that format guarantees fuzzy corners.
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dstoenner



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PostPosted: Fri Sep 09, 2016 12:32 pm    Post subject: Reply with quote

Dan,

The serial number on the Graflex Optar 162 is in the 300,000's which according to some other posts puts it in the 43 and there is a 43 date scratched onto the back of the shutter. When you look at the glass and shine a light from the side, you do not see the characteristic blue secondary reflection of the single magnesium coating that was used on lens of that era.

I knew that the 101 either Raptar or Ektar is a 2x3 lens only. And so far I have only used the 127 Ektar on 2X3. And yes I knew the 101's could only be a 2x3 format. I forgot I do have a 90 F6.8 Wide Angle Optar for the 4x5. I like taking pictures of old architecture so that one might be useful.

David
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45PSS



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PostPosted: Fri Sep 09, 2016 6:51 pm    Post subject: Reply with quote

There is no accurate record of Wollensak serial numbers. What is stated online is speculation. Is there a circled W on the lens name plate?
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dstoenner



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PostPosted: Sat Sep 10, 2016 11:53 am    Post subject: Reply with quote

45PSS wrote:
There is no accurate record of Wollensak serial numbers. What is stated online is speculation. Is there a circled W on the lens name plate?


These 3 lens are Graflex Optars, not Wollensak Raptar by marking. I have never seen a Circle W on a Graflex Optar and mine don't have one. Yes I know they are both made by Wollensak. I understand that what is on this site may not hold true but the 300,000 lens is not coated and I the 730,000 Optar is coated. The 101 Raptar has the Circle W on it and it looks coated.

David
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45PSS



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PostPosted: Sat Sep 10, 2016 7:23 pm    Post subject: Reply with quote

All Optar lens are Wollensak Raptar except the later ones marked Rodenstock. All Raptars are hard coated,
http://www.cameraeccentric.com/html/info/wollensak_2.html
http://www.cameraeccentric.com/html/info/wollensak_3.html
first page of both catalogs.
In the http://www.cameraeccentric.com/html/info/wollensak_15.html there is no mention of coatings. The Optar name began with the introduction of the Pacemaker line in 1947.

Early coatings do not have the Blue/Purple color of later coatings. I had a early 1930's Kodak Anastigmat that had a charcoal gray internal coating.
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dstoenner



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PostPosted: Sun Sep 11, 2016 11:21 pm    Post subject: Reply with quote

Charles,

I have seen those brochures of Wollensak Raptar lens and agree that they do say they are coated by 1947. I also agree that Optar is just the Graflex house name of a Raptar.

Here are some shots of my 162mm F4.5 Optar I was talking about. Here is a picture of the backside where I hope you can see the date it says D-7-9-43.



Here is a full front side with the shutter blades open. I cannot see any coating reflections here that i would normally see.



I know you talked about that entry of dating Optars but if this date is accurate for the lens then 324,180 + 1.5x60,000 would put 500000 in 1945 when the Wocoated started.

I got this lens to go on an old 4x5 per-anniversary that I am going to put back together as a bookshelf item in my office. it will never take pictures. There is some haze and fungus and I believe separation of rear set of elements. But on the surface this looks like a clean front element with respect to scratches.

I would appreciate any observations you might have on this because I am baffled.

David


Last edited by dstoenner on Sun Sep 11, 2016 11:26 pm; edited 1 time in total
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dstoenner



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PostPosted: Sun Sep 11, 2016 11:25 pm    Post subject: Reply with quote

We have sort of gone on a rabbit trail here from my initial question.

I know both Charles and Dan say they have seen cleaning marked Ektars. Does anybody know the relative hardness of the coating that Wollensak used vs Kodak?

David
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45PSS



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PostPosted: Mon Sep 12, 2016 1:21 am    Post subject: Reply with quote

The next question about you Optar is "Is it in its original shutter?" The lens cells could have been swapped to an earlier shutter with less wear and bad elements. I agree it looks clear/uncoated. If I remember correctly from a post 10+ years ago the Optar name was not used until the introduction of the Pacemaker series of cameras.

I wonder if a search through patents would reveal anything about the coatings.
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Dan Fromm



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PostPosted: Mon Sep 12, 2016 1:05 pm    Post subject: Reply with quote

David, MgF is MgF is MgF. There's very little difference between lens makers.

A variety of softer coatings were used before vacuum deposition of MgF became widespread, but post-1946 lenses from EKCo and Wollensak were all coated the modern way. I have small piles of WoCoated lenses, none badly scratched, and of (L) Ektars, a few badly scratched.

Going back to y'r original question, I think you got an unlucky sample of used Optars. I've shunned used tessar type Optars and Raptars in favor of used tessar types from EKCo, Zeiss and B&L because of concerns about errors in computing the prescriptions, not because of concerns about getting a badly scratched lens.
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dstoenner



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PostPosted: Mon Sep 12, 2016 4:10 pm    Post subject: Reply with quote

45PSS wrote:
The next question about you Optar is "Is it in its original shutter?" The lens cells could have been swapped to an earlier shutter with less wear and bad elements. I agree it looks clear/uncoated. If I remember correctly from a post 10+ years ago the Optar name was not used until the introduction of the Pacemaker series of cameras.

I wonder if a search through patents would reveal anything about the coatings.


Charles,

I have no history on the lens so I don't know if it could have been replaced in this shutter. I did do a search on patents by Wollensak and interesting I found a site that has all patents issued to camera companies.

https://sites.google.com/site/fromthefocalplanetoinfinity/patents

I downloaded the Wollensak archive and looked at it. Not one patent in their portfolio has anything to do with a coating or from what I can tell by title, a lens. They must have paid for patent licenses or were using processes that had lost their patent protection both for their lens designs and coating processes.

I did find a sort of Wollensak company history article (32 pages long). It dealt with binoculars more than anything else. In it, it said all photographic lens were coated from 1939 on. But then made a reference to MgF2 coating wasn't used on binoculars till after the war. Since the binoculars that they were referring to were used by military, I would have thought those would have gotten the coatings, long before photographic lenses would.

So the jury is still out. Inconclusive and contradictory information at best.

So just a question. There is a post in this forum about Wollensak being at serial number 500,000 in 1945. Do you disagree with that statement? If so, do you have any idea where they might have been?

Another thought might be that Wollensak did coat all of their Raptars and Velostigmats and marked them with the W/C marking. But didn't coat the units they made for Graflex till after the war when more men and machinery would be available. That would make most everybody's statements line up.

David
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dstoenner



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PostPosted: Mon Sep 12, 2016 4:22 pm    Post subject: Reply with quote

Dan Fromm wrote:
David, MgF is MgF is MgF. There's very little difference between lens makers.

A variety of softer coatings were used before vacuum deposition of MgF became widespread, but post-1946 lenses from EKCo and Wollensak were all coated the modern way. I have small piles of WoCoated lenses, none badly scratched, and of (L) Ektars, a few badly scratched.

Going back to y'r original question, I think you got an unlucky sample of used Optars. I've shunned used tessar type Optars and Raptars in favor of used tessar types from EKCo, Zeiss and B&L because of concerns about errors in computing the prescriptions, not because of concerns about getting a badly scratched lens.


Dan,

Thanks for the followup. I guess I have learned a lot along the way so now I am more savvy buyer.

What got me on this whole kick was the 127 Ektar that I got was far more sharper than the 101 Raptar and any equal aperture. SO just based on that I started to question how really good Wollensak was an an optical company. Then seeing what appeared to be a weakness in their coatings only enhanced that feeling. So now my 2 Graflex Optars are being relegated to 2 bookend cameras, a 3x4 and a 4X5.

David
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