Lens contrast: how much does it really matter?

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Originally Posted by E. von Hoegh

Ian, what about the Hoya HMC filters? I have one 72mm (the only HMC I have) that's very good, I use it as a protective filter on a 20mm WA lens, as far as flare and reflections go it might as well not be there. Are they all this good or should I watch out?

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Hoya's Multo Coating is usually vey good, the lens problem was a mistake in the design/production probably to cut costs it wasn't faulty coating rather they just didn't coat every air/glass interface. There's no problems with Hoya's top Tokinna range of lenses. Hoya used to hide the links between the two companies for some obscure reasons now the link is acknowledged openly.

Coatings have improved further over the years since Multicoating became common with the advent of SMC Takumar lenses, it was pioneered by Zeiss in West Germany and put into production by Pentax. I've never had an issue with Hoya lenses and I've been using them for about 38 years.

Ian

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Originally Posted by Klainmeister

Neither linky is worky... =[

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Hmmm, they work for me, so I'm guessing that it's because it automatically logs me in to the forum.

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Originally Posted by Brian C. Miller

See? You guys need to use a Drem Glasgnademeter to measure bokeh. That little Nikon meter just gets pegged when the LF lenses are placed on it. Plus, you need real statistics and measurements about that lens, not a one-size-fits-all number. The Leica Glasgeistometer used crystal prisms to obtain mean, standard deviation, radii, and the later versions could obtain inferential statistics as well. Unfortunately, most of these have been dismantled by new-age hippies to be used as necklaces and earrings.

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Originally Posted by Brian C. Miller

Things which make up a lens' grace:
1. Halo
2. Blur
3. Blur point distortion (even, centered, ring)
4. Formation
5. Edge distortion

Halo would be the amount that a reflected white object would intrude into an adjacent black object.
Blur would be the amount of defocus blur, based on distance from the focus plane, and also per aperture.
Blur point distortion would be the amount of distortion of a blurred point object, measured for eveness. 0 would be neutral, negative would be a ring, and positive would be a "hot" point. This may need to be expressed with deviation.
Formation would be blur point forms, such as the hovering dots from strainer-type discs or aperture leaf patterns.
Edge distortion would be what happens at the edge of the lens coverage, including "swirlies" compression and notable drop in resolution and coverage.

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Hee hee hee. I remember that thread... :)

Well, here's my experience with the coating issues. In the mid 70's a friend and fellow photographer, was given his grandfathers mint condition Leica DS M3 with a 50mm f2 collapsible Summicron. I was using a Nikkormat Ft2 with the new multi-coated Nikkor 50mm f2. We decided to see what the differences were between the lenses by loading some Plus-X into our cameras, and shoot the same pictures using a stationary tripod. We really didn't know much about lens design or anything, we were just curious. Though I think the Nikkor was a 6 element design, I'm not sure about the Summicron, but I'm sure someone will know. The results (film dev together and printed 8x10 with the same enlarger) showed some differences on some pics, and none on others. Shooting into the sun or bright scenes showed less contrast with the Summicron, and better contrast with the Nikkor. No lens hoods or filters were used. Including the sun in the frame made these differences more severe. Otherwise, most pics looked the same, with the Summicron showing a little more contrast in a couple of pics. (just the nature of the lens?) So I guess that multi-coating can make a difference in some shots, while not in others. Might be interesting to see the difference between the non-multi-coated Nikkor and the multi-coated one now, though I imagine the differences would probably be about the same.

Just because a lens is coated, does not mean you can get away without a proper lenshood.

Your experience is just what I would expect, comparing a 1950s single coated lens to a new multicoated lens.

Lets put it in clear way.

MTF test is the small tip of the iceberg , there is thousand times more problem under it.

MTF test being done with the help of Optical Transfer Function. Think you have a Nakamichi amp and sending its input cable different sinus waves. Every amp make these different sinus waves at a different height at the end.

Optical transfer function OTF describes this phenomenon with the help of two variables.

First MTF , You all saw this graph and phase variable.

You can put MTF with single graph but you can not put phase variable less than 60 graphs. These are aberrations or the bump and the valleys of the distortion on the image.

If you are interested , you will start to not look to mtf graph when buying the lens but the companies photographers portfolio spread to the past and you will start to see the real thing.

Every company have a tradition to put these 60 errors in a combination to create their visual brand.

You can make two same MTF graph lens and they can be extremelly different .

Thats why if you want same character photographs like Ansel Adams , you have to own his lens. Otherwise you end up at another place.



Umut

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Originally Posted by Ian Grant

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Ian

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Thank you.

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Originally Posted by E. von Hoegh

Thank you.

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Comparisons of a Leitz Summicron lens to a Nikkor adds yet another can of worms because the design criteria are so different and it's not down to the coatings. Leitz design for tonality and very high definition, Nikon design for a snappier more contrasty image that on a first glance appears sharper.

Back in the early 1990's I shot some colour images at a friends wedding, whan he saw the results he said oh you've bought a new camer these are superb, he was amazed when I told him it was an early 50's M3 and Summicron. It's subtleties that make the difference, sometimes they are less detectable.

Ian

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Originally Posted by E. von Hoegh

Just because a lens is coated, does not mean you can get away without a proper lenshood.

Your experience is just what I would expect, comparing a 1950s single coated lens to a new multicoated lens.

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Correct. I go a lot further, with multicoated (doublesided) filters, as required and a lens hood. I am not averse to spending $1,000 on a single filter. I don't take shortcuts.

Too many people put a $5.00 bottle end filter on a $4,000 lens and think all will be well and good. The truth is that a poor quality filter compromises the optical integrity of the lens, resulting in flare, loss of contrast and in the worst of cases, loss of clarity. Part of the problem is that cheap filters are promoted by dealers at POS, at the time of sale. They ought to be convincing the person on the other side of the counter that he/she is paying a lot of money for a lot of lens for a good reason: that of technical refinement that is far, far removed from the emotive, nostalgic "high quality" lenses of 30 to 50 years ago, and that the filter must be equal to the quality of the lens, but in no way compromise it. But in this digital, fast-sell age, it seems making the sale is more important than building quality on quality when accessorising, filters particularly.

I owned 80s Summicron on Leicaflex and it was faraway colorful than Summitar and Elmar. It was good as all other Leitz glass under dim light or subdued light but when you take street shots , flat colors were exploding. And plastic colors were looking like fluorescent. But whatever the condition , skin colors were amazing. I think canadians have other Color MTF preference. Extremelly sharp and whatever you shoot , there is something calls you inside of composition , a window , marble wall etc. I always prefer Sum class lens to El class lens. I studied Leica since when I was 14 years old and reading Amateur Photographer and Photo Technic. Digital ruined everything.