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Comparison of MF lenses

stngoldberg

Well-known member
Hi Rod,
So are you saying that the Schneider APO-DIGITAR 5.6/210 T 32degree MC is a less desirable lens?
Stanley
 

jerome_m

Member
What would be a great project for forum members to do is contribute to threads where individual images shot with specific focal length lenses could be looked at. But as someone that has been shooting large format and medium format professionally and personally for over 30 years, all I can say is, technique can have a lot to do with the results as well as the condition of the lenses themselves. "C'est la vie."
I have posted a simple test and results for Hasselblad H lenses here:
http://forum.luminous-landscape.com/index.php?topic=94852.0
(I can't do the same here because of image size restrictions, but there is a link at the end to get the images when one is not a member of luminous-landscape).

I would be interested in results of a similar test for Pentax, Leica or PhaseOne.

As people have noted here, this particular test is not adapted to longer focal lengths, because of atmospheric turbulence and haze. This is why I only tested lenses up to 100mm focal length.
 

jerome_m

Member
I was not able to find MTF data for the central shutter lenses made by Schneider Kreuznach for the PhaseOne / Mamiya cameras.
Actually, I found this page with some data about these lenses today:

http://www.getdpi.com/forum/redirect-to/?redirect=https%3A%2F%2Fcaptureintegration.com%2Fschneider-ls-lens-mtf-charts-for-phase-one-mamiya%2F

I tried to scale the curves available for the 28mm lenses so that they can be directly compared (at f/8 and with the limitation that Schneider Kreuznach uses higher values of 15, 30 and 60 lp/mm instead of 10, 20, 40):
 

Steve Hendrix

Well-known member
For HC lenses, there is hasselbladdigitalforum.com, but it does not offer comparisons with other brands.



Quite on the contrary, many dealers have a full or almost full collection of lenses for rental.

You are correct Jerome.

The bigger issue is not whether we have them on the shelf, but dedicating the time to do a proper test. It's easy to do a test. But quite difficult and time consuming to do a proper test with equivalent conditions for all the participating products that is of a quality that qualifies for publishing.

And it isn't that we (or any responsible, service-oriented dealer) would wish to hide a lens that doesn't perform well - as was mentioned in one post. We certainly know which lenses don't perform well, even if we don't have an appropriate publish-ready test available. I've performed many, many lens tests that just weren't quite up to the level of a publishable test for various reasons, but gave me enough information to be able to know which lenses perform better or worse than others, and in which situations.

We specifically test internally to know which lenses to recommend or not. If a lens isn't a good performer, there's no..... darn way in the world we're going to hide that information from our clients.

Do you think _____ (fill in the blank for any number of online merchants) cares if someone buys a crappy lens from them?

I have many lens comparison files that I personally send to my clients who are considering various lenses. And further, we perform custom tests for individual clients - I will ask what type of scene/subject matter, and then will shoot the lenses in question and share the files with that client.

So - unfortunately, a comprehensive, all things equivalent lens comparison across numerous product lines up and down doesn't exist. But it is definitely possible to find out what you need to know. There's many resources out there, forums, end users, manufacturer data, and yes, (some) dealers.


Steve Hendrix
Capture Integration
 

jerome_m

Member
And it isn't that we (or any responsible, service-oriented dealer) would wish to hide a lens that doesn't perform well
I dont think that there are many MF lenses which do not perform well. There may be better lenses than other, but my experience with MF has always been reasonably satisfying. My idea is not to find a "perfect" lens, but rather to learn about the design choices of the various brands involved.

I have many lens comparison files that I personally send to my clients who are considering various lenses. And further, we perform custom tests for individual clients - I will ask what type of scene/subject matter, and then will shoot the lenses in question and share the files with that client.
I am not a client. I am generally satisfied with the lenses I have (Hasselblad H) and do not need further ones. Neither am I likely to get equipment from a dealer in America, while I live in Europe. Under those circumstances, I would not think it fair to require custom tests from a dealer I have no intention to buy equipment from.
 

Steve Hendrix

Well-known member
I dont think that there are many MF lenses which do not perform well. There may be better lenses than other, but my experience with MF has always been reasonably satisfying. My idea is not to find a "perfect" lens, but rather to learn about the design choices of the various brands involved.
That may be true, but there certainly are lenses that we will simply not recommend, depending on what the application is. And whether any would be considered "poor performers" (someone else's words, not mine) or not, there certainly are differences in performance, which is really the jist of what you're after. My comment regarding poor performing lenses was more focused in response to whether a dealer would conceal such information from a potential client. Didn't mean to confuse things.


I am not a client. I am generally satisfied with the lenses I have (Hasselblad H) and do not need further ones. Neither am I likely to get equipment from a dealer in America, while I live in Europe. Under those circumstances, I would not think it fair to require custom tests from a dealer I have no intention to buy equipment from.
I understand - again, this is in response to the broader question for others of how to get performance data for these lenses. In your case though, I would expect any dealer that is in a vicinity you do business in that is focused on medium format solutions to have a similar inventory and a similar willingness to provide custom examples.


Steve Hendrix
Capture Integration
 

jerome_m

Member
Now that I found some MTF curves, I tried to compare them. Of the curves available for wide-angle MF lenses, only the ones for Hasselblad H and Phase One / Mamiya lenses can be directly compared and only at f/8. Since the only wide-angle lenses with the same focal length between the two brands are the 28mm and 35mm, there is not much data which can be compared directly. For the Hasselblad HCD 28mm, the curve only goes to 31mm (the corner of the x1.1 sensors): the lens does not cover the x1 sensor size. Still, the comparison is useful for people using the smaller sensor sizes, including the new cmos based offers.

The curves for the 28mm and 35mm at f/8 have been scaled and stacked on top of each other for direct comparison. Hasselblad curves are black and Phase One / Mamiya curves are coloured. It would seem that the Hasselblad lenses are more homogenous from centre to corner.
 

RodK

Active member
Hi Rod,
So are you saying that the Schneider APO-DIGITAR 5.6/210 T 32degree MC is a less desirable lens?
Stanley
Not at all. But these are no longer made apparently, and the quality of the Apo-Symmar-L is exceptional, and similar, if you cannot find one of the T series.
The Rodenstock Apo-Sironar-S series is also in this class of superb performers if used at correct apertures.
Rod
 

RodK

Active member
Now that I found some MTF curves, I tried to compare them. Of the curves available for wide-angle MF lenses, only the ones for Hasselblad H and Phase One / Mamiya lenses can be directly compared and only at f/8. Since the only wide-angle lenses with the same focal length between the two brands are the 28mm and 35mm, there is not much data which can be compared directly. For the Hasselblad HCD 28mm, the curve only goes to 31mm (the corner of the x1.1 sensors): the lens does not cover the x1 sensor size. Still, the comparison is useful for people using the smaller sensor sizes, including the new cmos based offers.

The curves for the 28mm and 35mm at f/8 have been scaled and stacked on top of each other for direct comparison. Hasselblad curves are black and Phase One / Mamiya curves are coloured. It would seem that the Hasselblad lenses are more homogenous from centre to corner.
They tend to use F8 because diffraction starts to show up past F8.5 with 80mp backs and so they test and graph all the lenses there so they only need do one set of graphs. This is even though a lower megapixel back may allow use to F11.5-16 with little or no apparent diffraction showing up. A usaer needs to test for their personal GE factor.(GOOD ENOUGH)
The longer lenses will also show far less than the standard to wide angles. So with an 80mm and a 120-150mm, and longer, you may be happier at F16 and with a 40-60mp back F22 may be outstanding.

Rod
 

jerome_m

Member
Traditionally, MTF curves are presented at full aperture and f/8. This is also true for 24x36 lenses and was already done before the advent of digital photography. I think the reason is not because it is expected that the photographer will use f/8, but because that aperture minimises the aberrations of large apertures, while still showing some useful differences.

As to the effects of diffraction, theory predicts some loss of contrast between f/8 and f/11 on my 6 µm back and my tests confirm that effect. But the loss of contrast will not show on prints at that aperture, even large prints.
 

Oamkumar

Member
This is a very nice discussion and very informative. Any information about the quality of Schneider Kreuznach 120mm TS f/5.6 lens compared to mamiya 120mm f4 macro D MF lens. They advertise the tech camera image quality with this lens. Is that true?
 

ErikKaffehr

Well-known member
Hi,

Just as a small comment. Even on a system degraded by diffraction there is still benefits to high resolution backs. Quite true, if the image is viewed at actual pixels, the effect of diffraction would be more noticeable. But, would the higher resolution image be downscaled, the image would be better than the larger pixel image.

The other aspect is that unless MTF goes below say 5-10%, detail can be restored with adequate sharpening.

Another consideration is that 40 MP backs are mostly crop frames, so a 40 MP back may have smaller pixels than a full frame 60 MP back.

Regarding MTF curves, you are absolutely right that any really good lens is affected by diffraction at f/8, truly excellent lenses may be affected by diffraction as early as at f/4. But this is all, "the more you have the more do you have to loose". A lens that becomes limited by diffraction at f/5.6 will be sharper than a lens limited by diffraction at f/8 at most apertures.

Best regards
Erik


They tend to use F8 because diffraction starts to show up past F8.5 with 80mp backs and so they test and graph all the lenses there so they only need do one set of graphs. This is even though a lower megapixel back may allow use to F11.5-16 with little or no apparent diffraction showing up. A usaer needs to test for their personal GE factor.(GOOD ENOUGH)
The longer lenses will also show far less than the standard to wide angles. So with an 80mm and a 120-150mm, and longer, you may be happier at F16 and with a 40-60mp back F22 may be outstanding.

Rod
 

jagsiva

Active member
This is a very nice discussion and very informative. Any information about the quality of Schneider Kreuznach 120mm TS f/5.6 lens compared to mamiya 120mm f4 macro D MF lens. They advertise the tech camera image quality with this lens. Is that true?
The problem I had with this lens is vibration. The foot on it is quite small and when combined with the massive shutter on the DF, it was unusable in anything less than 1/250. This was a few years ago, Phase may have changed the design now. I was using MUP so, that was not really an issue.
 

Oamkumar

Member
The problem I had with this lens is vibration. The foot on it is quite small and when combined with the massive shutter on the DF, it was unusable in anything less than 1/250. This was a few years ago, Phase may have changed the design now. I was using MUP so, that was not really an issue.
Hi,
Shutter vibration will be an issue. But I am doing flash photography and do not think the shutter vibration affects my kind of shoot. May be I'm comparing images from the tech cameras. Before going to the tech cam, I wanted to know about the 120mm TS lens. If it's really great, I will not have to go to tech cam area. I'm mainly doing products such as jewellery and fashion.
Thanks.
 

miska

Member
Does the new XF body improve the situation with regards to vibrations ? I think I read somewhere that with it, you can just use the LS by itself, and avoid vibrations (almost) completely.
 

Paul2660

Well-known member
Does the new XF body improve the situation with regards to vibrations ? I think I read somewhere that with it, you can just use the LS by itself, and avoid vibrations (almost) completely.
I have asked my dealer about this, i.e. can you defeat the focal shutter on the XF and just use the LS shutter? That would be great, as on the DF+, this was not possible.

The XF supposedly has a vibration sensor that from what I have read, will delay the shutter (focal) until the vibrations have reached an acceptable level. It has a seismic type sensor built in. But I have not really read that much on this feature yet, as I have only been able to find the marketing literature. However if you could defeat the focal and only use the LS shutter that would be a great new feature.

Paul
 

dougpeterson

Workshop Member
I have asked my dealer about this, i.e. can you defeat the focal shutter on the XF and just use the LS shutter? That would be great, as on the DF+, this was not possible.

The XF supposedly has a vibration sensor that from what I have read, will delay the shutter (focal) until the vibrations have reached an acceptable level. It has a seismic type sensor built in. But I have not really read that much on this feature yet, as I have only been able to find the marketing literature. However if you could defeat the focal and only use the LS shutter that would be a great new feature.

Paul
With current firmware the focal plane shutter is disabled 100% when shooting from live view.

In future firmware I would expect to see additional options for locking the focal plane shutter including the vibration mode you mention. But those options are not in the current firmware and are therefore in the believe-it-when-you-see-it category.

In general purpose usage the XF will always fire the focal plane shutter as this allows faster maximum recycle times (for technical reasons). But in slower tripod based non flash work there are significant advantages to isolating the exposure to just the leaf shutter and I expect a variety of options (in addition to the one option present in today's firmware) in the future addressing this need.
 

dougpeterson

Workshop Member
Hi,
Shutter vibration will be an issue. But I am doing flash photography and do not think the shutter vibration affects my kind of shoot. May be I'm comparing images from the tech cameras. Before going to the tech cam, I wanted to know about the 120mm TS lens. If it's really great, I will not have to go to tech cam area. I'm mainly doing products such as jewellery and fashion.
Thanks.


Very good lens optically but kind of a hassle to use as you must manually open-up/stop-down the lens manually. Also you'll need extension rings to do any macro work and you'll need to mount the lens to the tripod rather than the body to minimize the change in POV when making optical movements.

It's one of the lenses we prefer not to sell until someone has tried it hands on.
 

Egor

Member
Very good lens optically but kind of a hassle to use as you must manually open-up/stop-down the lens manually. Also you'll need extension rings to do any macro work and you'll need to mount the lens to the tripod rather than the body to minimize the change in POV when making optical movements.

It's one of the lenses we prefer not to sell until someone has tried it hands on.
Doug is right about this lens (SK 120 TS). We had high hopes for the 120TS for exact same reasons (small product shoots with some movements for focus plane adj); but the dang thing was a pia to even do movements with. It requires rotation of lens body and then counter rotation to achieve desired tilt movements....Even after a week of using it (on loan from DT...thanks to Lance at DT, really appreciated that :) it was not a viable solution. and thats not even taking into account the manual settings and/or the extension rings for macro.
We were hoping it would be designed like Canon's TS-E lenses but it is not. Canon's TS-E lenses are great functionally, but not good enough glass for our mfd sensors plus didn't want to get too complicated trying to make them work on the DF+'s

recently we tried tech cam route and purchased SK 120mm ASPH/Copal-0
Unfortunately, there is a high frequency vibration in the Copal shutter that only allows sharpness at flash durations of 1/6000th sec or faster (we tested it out...Don't ask...we are getting it repaired :(....in any case, the 120 ASPH appears sharp enough compared to our PhaseOne 120 AF Macro but man, the tech cam version is a lot smaller! ( at least 1/4 the size) I was expecting more glass for that kind of money ;)
Anyway, when the shutter comes back from SK we will see how it stacks up.
 
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