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maericks
Joined: 15 May 2002
Posts: 21
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 Posted: Tue Apr 20, 2004 5:58 pm Post subject: |
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All,
Chris Perez just tested a 105mm F3.7 Ektar and put the results up on his website at:
http://www.hevanet.com/cperez/testing.html
He has results from a 101mm F4.5 Ektar on his medium-format lens test page at:
http://www.hevanet.com/cperez/MF_testing.html
Interestingly, the 105mm Ektar that he tested didn't appear to be a big improvement over the already-excellent 101mm Ektar. In fact, the 101 seemed to perform a bit better at the edges than the 105.
On a side note, both the 101 and 105 lenses stack up very well to the other medium format results that Chris has obtained.
[ This Message was edited by: maericks on 2004-04-20 11:02 ] |
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Dan Fromm
Joined: 14 May 2001
Posts: 2144
Location: New Jersey
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| Posted: Tue Apr 20, 2004 6:48 pm Post subject: |
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On 2004-04-20 10:58, maericks wrote:
All,
Chris Perez just tested a 105mm F3.7 Ektar and put the results up on his website at:
http://www.hevanet.com/cperez/testing.html
He has results from a 101mm F4.5 Ektar on his medium-format lens test page at:
http://www.hevanet.com/cperez/MF_testing.html
Interestingly, the 105mm Ektar that he tested didn't appear to be a big improvement over the already-excellent 101mm Ektar. In fact, the 101 seemed to perform a bit better at the edges than the 105.
On a side note, both the 101 and 105 lenses stack up very well to the other medium format results that Chris has obtained.
[ This Message was edited by: maericks on 2004-04-20 11:02 ]
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First, thanks very much for the news.
Two thoughts.
Chris' results for the 105/3.7 are center, middle, and edge on 4x5. His results for the 101/4.5 are center, middle, and edge on 2.25 x 3.25. So it isn't fair to compare the two tests' edge resolutions.
That said, I've long thought that my 105/3.7 wasn't as good a lens as my 101/4.5. That's why I sold it. I don't regret having sold it, although I've always wondered how much of the differences I saw were due to operator error. Chris' results slightly reinforce my lack of regrets.
He results for some of the Mamiya 7's lenses are astounding.
Cheers,
Dan |
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maericks
Joined: 15 May 2002
Posts: 21
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| Posted: Tue Apr 20, 2004 7:55 pm Post subject: |
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On 2004-04-20 11:48, Dan Fromm wrote:
First, thanks very much for the news.
Two thoughts.
Chris' results for the 105/3.7 are center, middle, and edge on 4x5. His results for the 101/4.5 are center, middle, and edge on 2.25 x 3.25. So it isn't fair to compare the two tests' edge resolutions.
That said, I've long thought that my 105/3.7 wasn't as good a lens as my 101/4.5. That's why I sold it. I don't regret having sold it, although I've always wondered how much of the differences I saw were due to operator error. Chris' results slightly reinforce my lack of regrets.
He results for some of the Mamiya 7's lenses are astounding.
Cheers,
Dan
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Dan,
Chris told me that he tested the 105 on a 4x5 camera, but I'm almost certain that he used 6x9 dimensions on the film plane to obtain measurements.
Also, the Rolleiflex cameras that Chris tested show some pretty amazing results as well. It's impressive to me to see lenses designed and manufactured in the pre-computer era meet and often exceed the performance of modern high-end glass.
--Mark |
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Dan Fromm
Joined: 14 May 2001
Posts: 2144
Location: New Jersey
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| Posted: Tue Apr 20, 2004 9:50 pm Post subject: |
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On 2004-04-20 12:55, maericks wrote:
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Mark, go back to Chris' site and look at his results for the 38/4.5 Biogon. That lens was designed in 1952 and hasn't been improved on yet. Hand calculations too.
I gather from his latest Rolleiflex results that he's figured out how to focus them accurately. And yes the results are very surprising.
Cheers,
Dan |
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maericks
Joined: 15 May 2002
Posts: 21
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| Posted: Wed Apr 21, 2004 1:36 am Post subject: |
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On 2004-04-20 12:55, maericks wrote:
Chris told me that he tested the 105 on a 4x5 camera, but I'm almost certain that he used 6x9 dimensions on the film plane to obtain measurements.
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I got the definitive answer from Chris in an e-mail this afternoon. His "edge" measurement was 2.25 inches from the center of the film. For comparison purposes, I think that the corner of a 6x6 negative is about 1.7 inches from center and the corner of a 6x9 negative is about 2.0 inches from center. |
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glennfromwy
Joined: 29 Nov 2001
Posts: 903
Location: S.W. Wyoming
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| Posted: Wed Apr 21, 2004 4:23 pm Post subject: |
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I have a 105/3.7 Ektar and while it's a good lens, I fail to see why it has such an outstanding reputation. Like I say, it's good, not what I would call great. In fact, after the last project I did with it, I was rather disappointed. I have a 105/4.5 that shows a far better image on the ground glass. Now that I have the shutter working properly, I am anxious to try it out.
_________________
Glenn
"Wyoming - Where everybody is somebody else's weirdo" |
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troublemaker
Joined: 24 Nov 2003
Posts: 715
Location: So Cal
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| Posted: Sat Apr 24, 2004 2:52 am Post subject: |
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Glenn,
I have two 105 3.7 Ektars. The older 1941 uncoated lens takes decent but not very contrasty images, about the same as an uncoated 101 I just cleaned up. Neither are spectacular if sharpness and contrast are the target result (maybe a little better than an Optar 101 that's coated). The later 1947 coated 105 is perhaps the type worth raving about, and I suspect the post war lenses are the ones that get most of the attention. Mine has the little circled "L" that someone here suggested was placed for marketing purposes. Regardless, I have not yet come across a better lens for my 2x3's. A 105 Xenar was close. Lucky me! I would definately like to get my hands on a nice 101 Ektar and compare. Were later 101's coated? Some folks here think quite highly of thier 101's, and I'll bet for good reason. It seems there is quite a difference across the board on vintage lenses, and very understandably since they are far from new and and often unkown past.
regards,
Stephen
[ This Message was edited by: troublemaker on 2004-04-23 19:53 ] |
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Dan Fromm
Joined: 14 May 2001
Posts: 2144
Location: New Jersey
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| Posted: Sat Apr 24, 2004 4:05 pm Post subject: |
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On 2004-04-23 19:52, troublemaker wrote:
Glenn,
I have two 105 3.7 Ektars. The older 1941 uncoated lens takes decent but not very contrasty images, about the same as an uncoated 101 I just cleaned up. Neither are spectacular if sharpness and contrast are the target result (maybe a little better than an Optar 101 that's coated). The later 1947 coated 105 is perhaps the type worth raving about, and I suspect the post war lenses are the ones that get most of the attention. Mine has the little circled "L" that someone here suggested was placed for marketing purposes. Regardless, I have not yet come across a better lens for my 2x3's. A 105 Xenar was close. Lucky me! I would definately like to get my hands on a nice 101 Ektar and compare. Were later 101's coated? Some folks here think quite highly of thier 101's, and I'll bet for good reason. It seems there is quite a difference across the board on vintage lenses, and very understandably since they are far from new and and often unkown past.
regards,
Stephen
[ This Message was edited by: troublemaker on 2004-04-23 19:53 ]
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A circle L on a Kodak lens indicates that the lens is coated. it is not a marketing gimmick. Starting shortly after WWII, all Ektars were coated. This includes post-war 101 Ektars. |
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maericks
Joined: 15 May 2002
Posts: 21
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| Posted: Sat Apr 24, 2004 4:21 pm Post subject: |
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On 2004-04-24 09:05, Dan Fromm wrote:
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A circle L on a Kodak lens indicates that the lens is coated. it is not a marketing gimmick. Starting shortly after WWII, all Ektars were coated. This includes post-war 101 Ektars.
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From what I can tell in the highly-reliable "web research" that I have done, Kodak started shipping (L) lenses around 1946. These "Luminized" lenses were hard-coated using a low-pressure chemical vapor deposition process that is very common now but was extremely high-tech at the time. Prior to that, at least some Ektar lenses were "soft-coated". The soft-coating layer was not durable enough to withstand routine handling and cleaning, so it was applied to the interior surfaces of lenses only.
The very nice Ektar page over at http://medfmt.8k.com/mf/ektar.html describes at least some of this. |
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Les
Joined: 09 May 2001
Posts: 2682
Location: Detroit, MI
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| Posted: Sat Apr 24, 2004 5:01 pm Post subject: |
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Hard coating wasn't the gimmick, but I expect you'll have a hard time finding "Luminized" in a dictionary. The engraving and the name were certainly a marketing gimmick, tactic, method of announcing to the world we have a much better lens than that pre war stuff.
With Kodak it was a circle L, Wolley had their W in a C, B&L had their yellow, blue and ?? dots, while Goerz found it better to have just one gold dot rather than a gold ring.
I have several Ektar and Anastigmat lenses from Kodak, both LF and MF in nature that are hard coated but didn't have the circle L. ( these were made during the war)
I doubt the circle L has any better coating than the hard coated un branded lens. |
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troublemaker
Joined: 24 Nov 2003
Posts: 715
Location: So Cal
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| Posted: Sat Apr 24, 2004 5:57 pm Post subject: |
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Ok, not to argue, but personal enlightenment...
Certainly the coatings were developed during the war, and "marketing" was meant to say packaged, labeled and distributed for a post-war consumer market. A definition for luminized (anyone have a sales brochure?) would depend on how the coating is meant to react with the light passing through it, but may loosly adhere to one of several definitions in a rather thick Websters for luminesence and similar words.
Example, but not limited to:
luminance 2: the luminous intensity of a surface in a given direction per unit of projected area...so the word luminance refers to the effectiveness of a given light on the eye (read lens and or media surface)regardless of its origin.
Ok, so a definition like this and others suggest to me that a "Luminized" coating is meant to correct, and or stabalize the light (image) passing through the coated surface. In the case of vintage hard coatings, was the process, intended to produce better results on new color films, or simply as a corrective device that benifitted contrast and color?
stephen |
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Dan Fromm
Joined: 14 May 2001
Posts: 2144
Location: New Jersey
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| Posted: Sat Apr 24, 2004 7:14 pm Post subject: |
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On 2004-04-24 10:57, troublemaker wrote:
Ok, not to argue, but personal enlightenment...
Certainly the coatings were developed during the war, and "marketing" was meant to say packaged, labeled and distributed for a post-war consumer market. A definition for luminized (anyone have a sales brochure?) would depend on how the coating is meant to react with the light passing through it, but may loosly adhere to one of several definitions in a rather thick Websters for luminesence and similar words.
Example, but not limited to:
luminance 2: the luminous intensity of a surface in a given direction per unit of projected area...so the word luminance refers to the effectiveness of a given light on the eye (read lens and or media surface)regardless of its origin.
Ok, so a definition like this and others suggest to me that a "Luminized" coating is meant to correct, and or stabalize the light (image) passing through the coated surface. In the case of vintage hard coatings, was the process, intended to produce better results on new color films, or simply as a corrective device that benifitted contrast and color?
stephen
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Coating doesn't, crazy discussions on various web sites nothwithstanding, do anything to improve a lens' color correction. Coating came in at about the same time as color films, which don't tolerate old cures for chromatic aberration like filters that cut out part of the spectrum. Some manufacturers, e.g., Boyer, seem to have redesigned their lenses to reduce chromatic aberration when they started coating. This coincidence may have fed some of the crazier discussions. And certainly Voigtlaender, who replaced uncoated Skopars and such with coated Color Skopars and such added to the confusion.
Coating improves light transmission and reduces veiling flare in lenses with many air-glass surfaces. Veiling flare can reduce contrast, hence perhaps reduce color saturation.
Lenses with few air-glass surfaces, e.g., 6/2 double anastigmats like the Dagor, 4/3 lenses like tessars, and 5/3 lenses like heliars, don't benefit much from coating. Although practical fast 6/4 double gauss lenses like Taylor Hobson't Opic and Panchros and Dallmeyer's Super Six came to market in the 20s, well before coating was available, those designs and 6/4 plasmat types benefit considerably from coating. Modern zoom lenses would be nearly impossible without it.
About the only lenses that benefit much more from multi-layer coating, which improves transmission even more, than from single coating are complex zooms. I remember my 1968 vintage single-coated 8-64/1.9 Angenieux that was around t/3.3 wide-open; not the most useable of cine lenses except at high noon. It gave fine color, but oh! was it dim.
Coating doesn't correct or stabilize anything, it brightens. "Lumenized" was, as marketing jargon goes, a pretty fair description of what coating accomplished.
Cheers,
Dan |
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troublemaker
Joined: 24 Nov 2003
Posts: 715
Location: So Cal
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| Posted: Sat Apr 24, 2004 8:32 pm Post subject: |
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Thanks very much for this info.
stephen |
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maericks
Joined: 15 May 2002
Posts: 21
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| Posted: Sat Apr 24, 2004 10:30 pm Post subject: |
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On 2004-04-24 10:01, Les wrote:
Hard coating wasn't the gimmick, but I expect you'll have a hard time finding "Luminized" in a dictionary. The engraving and the name were certainly a marketing gimmick, tactic, method of announcing to the world we have a much better lens than that pre war stuff.
With Kodak it was a circle L, Wolley had their W in a C, B&L had their yellow, blue and ?? dots, while Goerz found it better to have just one gold dot rather than a gold ring.
I have several Ektar and Anastigmat lenses from Kodak, both LF and MF in nature that are hard coated but didn't have the circle L. ( these were made during the war)
I doubt the circle L has any better coating than the hard coated un branded lens.
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Les,
Good point. I didn't mean to imply that the addition of the (L) was not a marketing gimmick. Hard coating itself is certainly a big improvement over previous soft-coating technologies that are too fragile to be cleaned without damage.
On another note, I'm particularly interested in how to tell whether or not a pre-(L)Ektar is hard coated. I have a 105mm F3.7 Ektar made in 1947 and a 100mm F3.5 Ektar made in 1945. Their optical formulae are reported to be almost, if not exactly, the same. I put them side-by-side under a halogen desk lamp and the reflection colors are quite different. The 1947 lens reflections are different colors, while the 1945 lens reflections are all very similar in color. What does it mean? Any Ektar experts care to weigh in? The link below points to a pair of pics I took under identical conditions with a Canon S10 digital camera with the white balance set on daylight.
http://www.westerickson.net/mark/misc/ektars.jpg
--Mark
[ This Message was edited by: maericks on 2004-04-24 15:32 ] |
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t.r.sanford
Joined: 10 Nov 2003
Posts: 812
Location: East Coast (Long Island)
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| Posted: Sat Apr 24, 2004 11:49 pm Post subject: |
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| How do the lenses compare when used to photograph a backlit subect. with the light source visible in the scene? |
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