140mm 210mm and 350mm Lenses Too soft

I've used a Contax 645 for about two years, together with a full compliment of lenses, and I've never been completely satisfied with the results from the 140mm, 210mm, and 350mm lenses. The wides are terrific, and the 120mm Macro is an outstanding optic, but the 140mm and 210mm, and to a lesser extent the 350mmm, have always left me a bit flat. The 140mm and 210mm are very even performers across the frame, and they all have that signature Zeiss quality of very smooth transistions from in focus to out-of-focus. However, none of these three lenses has really impressed me with their sharpness. I've tended to blame myself, too windy for the tripod, shutter speed a bit too low for handholding, not quite accurate enough with the focus override etc.

I've just run a fairly basic test, and the 140mm and 210mm in particular weren't very impressive. You can see 100% crops in the "Test Photos" gallery.

I taped a broadsheet newspaper to a wall (the newspaper is about 30 inches across the long side) and set up a Contax 645 on a tripod, moving the camera progressively further back so that the newspaper consistently filled the frame with a 120mm, 140mm, 210mm, Hasselblad 180mm mounted via an adapter, and 350mm lens. All the posted shots were taken at f4.0.

The film used was Provia 100 in a 220 vacuum back, scanned at 4000 dpi on a Nikon 8000ED. A heavy tripod, mirror lock up and a cable release were used for each shot. I appreciate it's hardly scientific, and in particular the focusing and alignement have to be questioned. All I can say is that I focused carefully, checking auto focus with a loupe directly on the focusing screen. At these magnifications (a 30 inch subject) the depth of field at f4.0 is the same for all focal lengths, about 100mm. If we halve it to be cautious that still gives 50mm. The surface of the newspaper had ripples that were about 5mm deep, and maybe misalignement introduced a further 20mm discrepancy from corner to corner, but that's still a total error that's well within depth of field limits.

Because the 140mm and 210mm were so inferior to the 120mm I did some further research. This is what I found.

1. The American magazine "Popular Photography" ran a comparison between Mamiya and Contax using 45mm, 80mm and 210mm lenses. The 45mm was pretty much a draw. The 80mm saw the Mamiya take a small advantage, but as the Contax lens is an f2.0 available light lens that's to be expected. However the 210mm was a different matter, the Contax 210mm significantly underperformed the Mamiya lens. You can see the charts and read the full report on the Mamiya web site.

2. The Zeiss web site shows the MTF curves for all their lenses across several camera manufacturers. All their lens tests are standardised. Comparing Contax to the Hasselblad equivalents shows that the Contax wide lenses are indeed world class, and the 120mm Macro is absolutely outstanding by any measure. However Zeiss's own figures put a question mark over the 140mm, 210mm, and 350mm. The 140mm underperforms the Hasselblad 150mm, the 210mm is on par with or maybe slightly better at the edges than the Hasselblad 250mm (which is a fifty year old design!), but both are significantly below the performance of the Hasselblad 180mm or the Hasselblad 250mm Superachromat. Looking at the Contax 350mm Tele-Apotessar it's clear that despite the impossing name and frightening price it's way, way down in performance terms when benchmarked against other exotic Zeiss optics such as the Hasselblad 350mm Tele-Superachromat or the Hasselblad 300mm Tele-Superachromat, or the Hasselblad 250mm Superachromat. It seems that in the world of Zeiss the appelation "Superachromat" means a lot more than "Tele-Apotessar"!

3. The Photodo web site has lens tests across many manufacturers. I believe these tests were made by Hasselblad employees in their spare time using Hasselblad's optical bench. Unfortunately the performance curves have recently been removed from their site, leaving just a virtually worthless single numeric score for each lens. However I downloaded a number of their detailed charts some time ago. Looking at these shows that the Zeiss charts are largely substantiated, with the Contax 140mm and 210mm coming out as indifferent performers.

4. Finally, the Hasselblad web site gives the MTF curves for their 645 H1 lenses manufactured by Fuji. The advice is always given that you can't compare MTF results between manufacturers, however I suspect that Hasselblad have used their own Zeiss optical bench with the same testing methodology that Zeiss used for the Contax MTF charts. They show that across the wide angles the H1 and the Contax 645 are very similar performers. However, matching the H1's 150mm and 210mm against the Contax 140mm and 210mm shows the now familiar story of substantial Contax underperformance.

When I look at the posted shots I'd put the Contax 120mm as the best performer. Followed by the 350mm and the Hasselblad 180mm at roughly the same level. This surprised me as I've used this 180mm lens for fifteen years, when mounted on a Hasselblad body I get the impression it fully matches the results I get with the Contax 120mm. I wonder if its performance is compromised slightly by the adapter needed for the Contax 645 body? Bringing up the rear, and trailing by some distance, are the 140mm and 210mm. Incidentally, I haven't posted the results here but I also tried them with the x1.4 Contax multiplier, and that certainly doesn't do either the 140mm or the 210mm any favours!

So, what does the forum think, have I got bad s&les of these lenses, did I screw up the test, or maybe mis-read the additional evidence? Or are the 140mm and 210mm the weak links in the Contax system?
 
Hmmm. Looking at your pictures of text, I'm not so sure you picked the the best test. First, I think you would have been better served if you used a lest test target (you can find one online to download). Second you've focused on only one aspect of lens performance. Frankly I would have liked to see the lenses tested against the lens test target and a color target. Sharpness is one important area of lens performance but so is color rendition, color fringing, distortion, bokeh, vingetting, micro-contrast, etc. I am ready to admit that the gap between the Zeiss lenses and Mamiya's (& Fuji's) has closed over the years. (in addition to my Contax 645, I have a Mamiya 7II which it a camera type that I wish Contax/Zeiss would produce). I was going to do a similar test on 80mm lenses that I have but never got around to it (maybe I will now). My understanding for discussions and test is that the Contax 645 80mm/f2 is the finest MF standard lens available -- better than the Ziess for Hassy (it should be it's alot newer design) and anyone else. In comparisions it should be tested at the same aperture f2.8 vs. f2.8, not f2.0. One can rexpect the elsn to be a little softer at f2.0. The 120mm Macro is a phenomenal lens -- I bought it instead of the 140mm since it is more flexible (super sharp at infinity as well as 1:1) --and it creates images of incredible sharpenss and contrast. The 140mm is a lens I am considering buying becuase of what it is designed to do -- take portraits. It is probably one of the best portrait lenses available. One of the reasons is the way it handles (as you point out) the transitions for in focus to out-of-focus areas. It has lovely bokeh. The highest possible sharpness isn't the most important characteristic of a portrait lens, the look of the images is and this is where the lens excels. As for the 210mm, I bought one because I got it cheap ($950). I had heard that some people were not happy with it, but really haven't used it to give an opinion. I also think you are right about the sharpness of the 350 Tele-Apotessor (which I don't have). What I've heard is that it isn't as sharp as the Super Apochromat. The 45mm is a very nice lens, and I am currently looking to get the 35mm, which is by all accounts the finest in it focal length, and like the 120mm blows everyone else out of the water.

I am concerned about just looking at sharpness as in the Pop Photo test, and about the "test" itself. The lenses were not test together at the same time (5 months apart) and while Pop Photo probably has a standard procedure for doing this, they could have been implemented differently by different people under different conditions. The edge resolution of the Contax 80mm is really suspect. The article on the Mamiya site is not written by Pop Photo but merely selected excerpts from the 2 different articles and weaves them together with Mamiya text. They only chose 3 "identical" focal lengths for the comparison (why not the 35mm or the 120 macro?, and why exclude the 140? a few mm's in focal length isn't that big a deal). Risking sounding like a Zeiss apologist, it is fairly suspect "comparision". I would like to see a good head to head test (of several lens parameters) including the macro, zoom and ultra wide lenses. I would also point out (rather cynically) that Mamiya is a bigger supplier of advertising revenue to Pop Photo than Contax. Magazines of their ilk have been know to be more favorable in their writting towards their larger advertisers

In short, some of what you say is consistent with what I've heard and read over the year, alot is not. I'd like to see a more rigorous and complete test of the lenses' performance before jumping to conclusions.
 
G

guy

This is a very interesting subject...and also a hard one to be definitive on. I have a lot invested in Contax (all 645) and am preparing to buy a digital back to add to it. My biggest worry is about the future of Contax but these lens issues are also important. I'm debating between the Leaf, Phase One and Imacon and am leaning towards the Leaf. What scares me is that, except for the Imacon, they are dedicated backs and if I have to switch cameras I'll have to sell the back which will be worth pennies the day after I buy it.

I will be using the back mostly for commercial work, still life and fashion. For fashion the 120mm is almost too sharp and I have been thinking about buying the 140mm. I use the 210 a lot and while it doesn't seem to be as sharp this isn't such a problem in fashion. It would be in still life.

I have never been thrilled with Mamiya 645. The whole system doesn't have a feel of being well built. The Hassy H1 doesn't use Zeiss glass which is why I chose the Contax. Maybe this isn't an issue anymore and I am just hung up on Zeiss but to me Hassy just should be Zeiss, especially considering the prices they are getting for Fuji glass!

I'd appreciate anybody's experience before I sink $20- 30,000 on a back. If only I knew Contax's commitment to the line...

Guy
 
Guy, I'm in the same boat in terms of getting a full-frame 645 digital back and realising it'll lock me into a camera system for the forseeable future. And like you I ruled out the Mamiya because it just didn't feel "right".

That left the H1 as the only Contax rival, I borrowed one for a weekend with the 50mm, 80mm and 150mm lenses. There was a lot to like, super big and bright viewfinder, fast autofocus, and flash synch to 1/800s.

But every camera system has its shortcomings and the H1 is no exception. It's heavier than the Contax, and the lenses are heavier still. The shutter is noisier. And it's a menu driven camera, and although fairly intuitive it's a dexterity challenge for anyone without a Playstation childhood!

Stupidly I didn't do any side-by-side shots with the H1 and the Contax, maybe I'll see if my local camera store will indulge me for a second time with another loan of an H1.
 

tessar_man

Active Member
Lotus M50 wrote: "... (in addition to my Contax 645, I have a Mamiya 7II which it a camera type that I wish Contax/Zeiss would produce).."

I feel the same way about the availability of MF rangefinders. Zeiss (Ikon) used to be the leader in this category with their Super Ikonta 6x6 and 6x4.5 series and given Kyocera's experience with the G rangefinders they could transfer some of that know-how to a 645 rangefinder -ideally a rugged folder - that is even more portable than the Mamyia M6/7 and Bronica 645.
Sorry for OT diversion here. Maybe an interesting separate thread. Jan
 

fotografz

Well-Known Member
Guy, don't many of the MF Digital back makers offer a buy back if you stay loyal to that brand? Also isn't Imacon H25 usable on all kinds of cameras? I think it has a universal adapter. That would be my choice, seeing that a full frame 645 is a pretty safe bet to be usable quite far into the future.

As far as the lens issues discussed in this thread. I found that you have to use a true "bench test" rig to get accurate results. I don't have such a rig, but I do use a bubble level and square to get the camera as dead on centered and square to the subject as possible. 350mm at f/4 anywhere near minimum focus, and DOF is a mole hair thick. Very tricky to test.

I just tested my 350/4 using a ProFoto 650 watt generator set to the lowest output. The Contax 645 was set to mirror up and 10 second delay. I used a Kodak ProBack set at ISO 100 (RAW),
Focus was done manually by using a Contax flip magnifier. The lens was set at f/4, shutter at 1/90th.

If this lenses isn't as sharp as Einstein amongst a gaggle of idiots, then I don't know what is. And the darn thing focuses down closer than any other big long lens I've ever used. Frankly, that was one of the reasons I got it, it allows me to get almost macro with portrait subjects (mostly men, as a woman would scream bloody murder at seeing every pore and whisker on their
pretty little faces).

The Hassey 350 APO may indeed be a bit sharper, but isn't that lens like $10,000.?

BTW, the 35/3.5 for the Contax isn't all that great. It has a bit of pin cushion distortion... which I discovered when shooting supermarket shelves and having to knit them together in one long panoramic file. If I do a (boring) job like that again, I'll rent a Hasselblad Super Wide ( there wasn't enough room for a 4X5).
 

alan_h

Member
Gary,
Sounds like you've done a serious test and have big bucks invested. The test shots you've uploaded really do look bad, I've done tests like this with my RTS IIIs but nothing like this with my 645. What kind of tripod & head are you using? Did you strobe it or use available light? I use a Gitzo G 1504 MK II and an Arca Swiss ball head. I've found that if I haven't completely locked down the column tight and put the mirror up I have introduced some noticable shake. I've always been happier with strobed shots for sharpness comparisons. I'll have to test my 210mm a bit more at f4. I have to admit that I'm usually at f8 to f32 for most of my shots. I do ocassionally think I was getting sharper shots on my old Hassy 500ELX but it was such a uncomfortable camera that I couldn't stand it. As far as Digital Backs, I've tested the Kodak 645C, Imacon 384C and the Canon 1Ds. The Imacon in four shot mode was astoundingly sharp (with the 120 makro). I think it blows away 4x5 for detail. I also like the fact that it will work on my Fuji GX680. I'm glad I didn't spring for the now discontinued Kodak DCS645C. I wasn't happy with their software or the image quality around the highlights. The new H1 does have a bright finder even with the monster zoom mounted on it. I wonder how long the batteries last!
 
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