Some reflections on my V-series Hasselblad/P45 kit…

[tjv]

But you're using an H camera, with autofocus, not a V with manual focus. An H is, relatively speaking at least, a lot newer and designed for much tighter tollerances than the V system ever was.

I have a V mount Credo 60 that I've never mounted on a V camera. Focus is perfect using a GG on my Linhof Techno, which suggests my back is in good alignment. I'm wanting to use the back on an SLR and I very much appreciate other peoples thoughts on using it with an older 500 series camera and the pitfalls, etc.

I don't get this discussion on focus, tolerances, etc... I use an H4D which was calibrated by Hasselblad a few years ago. When I take a picture, I point the AF at the subject, let the camera focus and focus is perfect. Each time.

 

[fotografz]

I don't get this discussion on focus, tolerances, etc... I use an H4D which was calibrated by Hasselblad a few years ago. When I take a picture, I point the AF at the subject, let the camera focus and focus is perfect. Each time.

Not only are the H lenses AF, they employ True Focus … which is not to be confused with True Focus-Absolute Position Lock. Before Hasselblad introduced TF-APL in the H4D, True Focus meant that each lens was mapped to make micro adjustments to correct for any focus shift. My H dealer once demo'ed this for me (on my H3D-II/39 if I recall correctly), and I could hear the lens make a tiny focus adjustment. It is one benefit of electronic control that the mechanical/manual lenses lack.

- Marc

 

[Miller]

Not only are the H lenses AF, they employ True Focus … which is not to be confused with True Focus-Absolute Position Lock.

I think this was called ultra focus. The mechanism is described in this article:
http://static.hasselblad.com/2015/02/the_evolution_of_lenses.pdf

 

[fotografz]

You are probably right. Early on I swear my dealer referenced it as True Focus (which makes sense if you think about it). It probably always was Ultra Focus, but I'm not sure now … my memory may be the only thing that's fuzzy … LOL!

No matter, the concept works.

Another interesting focus aid Hasselblad had was a sonar type audio/graph in the Phocus Software. You'd turn this on and make micro adjustments manually listening to the feed-back and watching the graph. He used that focus aid to shim my Schneider 120 Macro on a view camera.

Hasselblad has tried a lot of interesting innovations which aren't common knowledge. Some good, some not so good.

I think they are the first to make a back that directly shot DNG files. It was a H2D/22. Unfortunately, it was to early on in the DNG development and never worked all that well. I had one, and Hasselblad replaced it with a regular H2D/22 no questions asked.

- Marc

 

[Jack]

I have to reply even though I never used a traditional V body with digital -- but that caveat stated, I did use V and F lenses adapted to other systems for MF DB as well as DSLR capture

First comment -- P45+ was my first serious DB and I still have many images from it hanging on my studio walls. At it's current price-point, I have considered getting another one to use on a 203...

Lenses in general -- especially with MF, I think absolute sharpness is over-rated; and perhaps even more so, corner sharpness gets over-rated. There is so much more to making a "great image" than optical perfection, especially in the corners. In fact, I believe that some optical imperfections can be magnificent when used to advantage. Several legacy Hassy V and F lenses have pleasing aberrations (as does most Mandler era Leica glass).

My only point here is to forget about optical perfection -- most any MF lens is more than good enough optically to make great images -- and focus on making images that exploit your particular lens anomalies. :thumbs:

My .02...

 

[jerome_m]

But you're using an H camera, with autofocus, not a V with manual focus. An H is, relatively speaking at least, a lot newer and designed for much tighter tolerances than the V system ever was.

Actually, when I use manual focus on my H, I also get it right, which proves that it is possible to adjust the tolerances between the sensor plane and the ground glass plane to be small enough. And the discussion I answered was specifically about tolerances, that temperature variations would wreak havoc calibration, etc...

 

[ErikKaffehr]

Hi Jack,

I agree sort of, but…

I guess that many of us look into MF for ultimate image quality. After all, Ctein says in an interview with Michael Reichmann is that Micro 4/3 at 16 MP is good enough for his work up to A2-size (16"x23").

Personally, I have great respect for that view, especially as I have found that 12 MP on APS-C was good enough for A2 size.

On the other hand, some photographers like Charlie Cramer and Joseph Holmes found that the P45/P45+ was an adequate replacement for 4"x5". I guess that you need thrive for optimum quality to replace 4"x5".

Personally, I am a bit of image quality freak, but my measure is good tree tops. If I can have good tree tops at the corner of the image that look natural I am quite happy. They don't need to be extremely sharp, but they need to look good.

Best regards
Erik

I have to reply even though I never used a traditional V body with digital -- but that caveat stated, I did use V and F lenses adapted to other systems for MF DB as well as DSLR capture

First comment -- P45+ was my first serious DB and I still have many images from it hanging on my studio walls. At it's current price-point, I have considered getting another one to use on a 203...

Lenses in general -- especially with MF, I think absolute sharpness is over-rated; and perhaps even more so, corner sharpness gets over-rated. There is so much more to making a "great image" than optical perfection, especially in the corners. In fact, I believe that some optical imperfections can be magnificent when used to advantage. Several legacy Hassy V and F lenses have pleasing aberrations (as does most Mandler era Leica glass).

My only point here is to forget about optical perfection -- most any MF lens is more than good enough optically to make great images -- and focus on making images that exploit your particular lens anomalies. :thumbs:

My .02...

 

[ErikKaffehr]

Hi,

Thanks for calling that article to attention. I have read it several time but missed out on the "Ultra-focus" thing. I used to read Lloyd Chambers DAP-site and he essentially complained about AF on most cameras, like Nikon, Canon, Sony, Pentax and Leica. But it seems that he didn't complain on AF regarding the Hasselblad he tested. Nice to hear that Hasselblad handles focus shift when stopping down.

Just to say, it is a minor effect. If Hasselblad takes care of that they clearly deserve a honourable mention in the despatches.

Best regards
Erik

I think this was called ultra focus. The mechanism is described in this article:
http://static.hasselblad.com/2015/02/the_evolution_of_lenses.pdf

 

[AreBee]

Erik,

Nice to hear that Hasselblad handles focus shift when stopping down.

It is my understanding that the Leica S also takes focus shift into account when focusing.

 

[Jack]

Hi Jack,

I agree sort of, but…

I guess that many of us look into MF for ultimate image quality. After all, Ctein says in an interview with Michael Reichmann is that Micro 4/3 at 16 MP is good enough for his work up to A2-size (16"x23").

Personally, I have great respect for that view, especially as I have found that 12 MP on APS-C was good enough for A2 size.

If all you're looking at is the per-pixel image quality, then yes I'd agree. However, many of us believe there is (a lot) more to an image's net "quality" than per-pixel IQ -- I'll call it the "collection of pixels" IQ...

On the other hand, some photographers like Charlie Cramer and Joseph Holmes found that the P45/P45+ was an adequate replacement for 4"x5". I guess that you need thrive for optimum quality to replace 4"x5".

Charlie, Joe, Bill (Atkinson) and I all had this discussion, and I sold my 4x5 film gear within a few months of acquiring my P45+ as well. (FTR, Joe was slowest to adopt but not why you think -- he did not want to give up the easier focus with movements that a 4x5 GG offered. But then he owned a Tango scanner too )

Personally, I am a bit of image quality freak, but my measure is good tree tops. If I can have good tree tops at the corner of the image that look natural I am quite happy. They don't need to be extremely sharp, but they need to look good.

No problem, just make sure to account for field curvature with your MF lenses as by design they have more than M4/3 or DSLR glass does


Cheers,

 

[ErikKaffehr]

Bad design?

The Sonnars and the Planar 100/3.5 do not have this issue. When shooting landscape, I would say that flat field is a good thing…

What about the Schneiders and Rodenstocks? Do they also have field curvature? Sorry for asking, but I do not have those lenses so it is hard to find out…

Best regards
Erik

No problem, just make sure to account for field curvature with your MF lenses as by design they have more than M4/3 or DSLR glass does


Cheers,

 

[Geoff]

I have to reply even though I never used a traditional V body with digital -- but that caveat stated, I did use V and F lenses adapted to other systems for MF DB as well as DSLR capture

First comment -- P45+ was my first serious DB and I still have many images from it hanging on my studio walls. At it's current price-point, I have considered getting another one to use on a 203...

Lenses in general -- especially with MF, I think absolute sharpness is over-rated; and perhaps even more so, corner sharpness gets over-rated. There is so much more to making a "great image" than optical perfection, especially in the corners. In fact, I believe that some optical imperfections can be magnificent when used to advantage. Several legacy Hassy V and F lenses have pleasing aberrations (as does most Mandler era Leica glass).

My only point here is to forget about optical perfection -- most any MF lens is more than good enough optically to make great images -- and focus on making images that exploit your particular lens anomalies. :thumbs:

My .02...

Jack -

Much wisdom in this post. Thank you for this. The purpose of raising the issue of calibration is that it seemed rarely mentioned with regards to the beloved V cameras, and yet it may well be an issue for some folks out there, thinking they can put on a back, a lens and shoot away easily. The higher res the back, the more the precision required...

Your post brings up the concept of "good enough", which is oft overlooked in our zeal for pixel peeping, but is one to keep in mind. The shot below was taken with a 33mp back and a 47XL lens, not the top of the heap by any means - yet it will produce a razor sharp 16 x 20 image (equal to 4x5), and larger. Good enough is a good idea.

 

[Jack]

Bad design?

The Sonnars and the Planar 100/3.5 do not have this issue. When shooting landscape, I would say that flat field is a good thing…

What about the Schneiders and Rodenstocks? Do they also have field curvature? Sorry for asking, but I do not have those lenses so it is hard to find out…

Best regards
Erik

Actually in my landscape work, I find curvature a benefit as foreground corners usually sharpen up from the curvature.

Note that there is no free lunch in lens design -- as you eliminate linear distortion in a lens, you increase curvature; as you correct out curvature, you gain distortions (usually barrel) along with astigmatism and spherical aberrations... Planars* got their name from their symmetric design that specifically limited curvature -- which at the same time limited chromatic aberrations. And why they've been popular since their development in the late 1800's. But they are also known for adding spherical aberrations -- traditionally considered a negative trait, however Mandler put them to glorious purpose in his designs, at least IMHO *Basic design is a double-gauss with a 3rd element in each gauss pair.

 

[Jack]

Jack -

Much wisdom in this post. Thank you for this. The purpose of raising the issue of calibration is that it seemed rarely mentioned with regards to the beloved V cameras, and yet it may well be an issue for some folks out there, thinking they can put on a back, a lens and shoot away easily. The higher res the back, the more the precision required...

Your post brings up the concept of "good enough", which is oft overlooked in our zeal for pixel peeping, but is one to keep in mind. The shot below was taken with a 33mp back and a 47XL lens, not the top of the heap by any means - yet it will produce a razor sharp 16 x 20 image (equal to 4x5), and larger. Good enough is a good idea.

No argument, and I am an adherent of precise calibration -- really the only way you can get the maximum from ANY high resolution sensor.

To wit: My first "digital back" was a BetterLight scan back. It was ahead of its time and had a true "live digital focus" capability -- measured per color channel inter-pixel contrast. Anyway, I remember using it on a landscape shot in Yosemite where I had my 210 lens mounted. (The BetterLight had a 75mmx100mm sensor scan area so the 210 was a slight telephoto, like about a 120 in MF parlance.) I used an 8x loupe on the GG to get very close initial focus, then took a scan. I then turned the live focus on and saw I needed to make a small correction -- very small in LF terms -- by tweaking my focus knob approx 0.5mm to get the channels to peak. In the final image comparisons at 100% view, that 0.5mm extension "moved" the exact PoF from the roughly 300 meters distant horizon to the 30 meter distant tree I was actually wanting to focus on. We never had accuracy better than a good loupe with film, and moreover sheet film was never within 0.5mm of flat corner to corner anyway -- it's amazing we ever made any worthwhile images before digital :ROTFL: !

 

[jng]

Actually in my landscape work, I find curvature a benefit as foreground corners usually sharpen up from the curvature.

Jack,

You make a great point here. Ultimately it's about understanding the properties of your tools and applying this knowledge to make the images you want, in this particular case turning a bug into a feature. I mentioned in an earlier post that I sold off my 50mm FLE because of excessive field curvature, but in fact two of my favorite recent images were made with it, taking advantage of the field curvature to bring the foreground into focus.

- John

 

[Jack]

John,

Exactly -- while "curvature" doesn't pencil out well on technical lens specs or when used to photograph flat test charts, brick walls or for copy work, it is in fact a non-issue for most real-world general photography uses. (How often do you need perfect corners in a typical image?) And then as described, it can be a feature for many applications.

Take Geoff's image above -- who gives a crap if the clouds in the upper corners aren't crisp? Yet the 47SA has a minor curvature which may have helped the extreme lower corners. Regardless, the image is stellar and appears laser sharp corner to corner, all from a lens that does not have a stellar "digital" reputation.

 

[ErikKaffehr]

Putting things a little bit in perspective

Hi,

When I got my Canon 16-35/L for the Sony A7rII I did a few comparisons with the Hassy P45+ combo. The Canon 16-35/4L is a remarkably good lens.

This link shows a comparison between the Canon 16-35/4 at 24 mm on the Sony and the Distagon 40/4CF on the P45+: http://echophoto.dnsalias.net/ekr/Articles/P45+_vs_a7rII/WA/

Here are some of the images, the whole image (P45+):

Now, lets look at the centre, the P45+, image looks pretty sharp although it has aliasing:

Now, moving a bit to the right, we see that the Distagon 40/4CF looses significant sharpness:

While the the Canon 16-35/4 is still very sharp:

Extreme corner is better on the Distagon 40/4CF:

Than on the Canon zoom:

If we check the foreground in the bottom area, the Canon lens (on the right) is clearly better than the Distagon (on the left)

Distagon/P45	Canon 16-35/4 A7rII

I also made such a comparison with the Distagon 60/3.5 CF, and that lens could also not keep up with the Canon zoom.

Now, this is all pixel peeping. I am absolutely sure that I could make an absolutely good A2 size print from that Distagon / P45+ image. Would it hold for 30"x40"? I guess so. It may need a bit more sharpening outside the central area. It could be the case that my Distagon is a bad sample, but Hasselblad published MTF curves for the lens and they were not so great. Not showing any MTF curves here, but here are data for most lenses: Hasselblad Historical - Zeiss Lens Data Sheets

Best regards
Erik

 

[bensonga]

We never had accuracy better than a good loupe with film, and moreover sheet film was never within 0.5mm of flat corner to corner anyway -- it's amazing we ever made any worthwhile images before digital :ROTFL: !

Reading through some of the posts on this thread, I have had those same thoughts.

I was just looking at some of my prints from 4x5 and medium format negatives shot 30-40 years ago and then realized it was sheer luck they turned out as well as they did.

Gary

 

[ErikKaffehr]

Hi,

But, I guess that you shot large format stopped down. Let's assume f/16. The defocus of 0.5 mm would cause a CoC of 0.031 mm, about what would be regarded sharp on 135 film, according to the DoF tables, on the P45+ the same CoC would cover about 16 pixels.

Another thing is that with film we had several steps, loosing some sharpness in all of those. With digital, we suddenly have sharpening in the mid of the processing pipeline. So I guess times are changing.

But, I would agree that we put a bit of to much emphasis on image quality.

This interview with Ctein may be interesting (membership required): https://luminous-landscape.com/videos/conversation-ctein/conversation-ctein/

Around the middle he says that 4/3 or APS-C is about optimum size. He can compare his 16"x20" die transfers to his 17"x22" Epson prints from the 4/3. Is it MF quality? Absolutely?

Do I agree? I don't know. I started with a 6MP Konica-Minolta and I am at around 40 MP now. I made many of my best images with 12 MP APS-C, good enough for A2 size (16"x23"), but I would rather make a 30"x40" print from 40MP than from 24MP.

Best regards
Erik

No argument, and I am an adherent of precise calibration -- really the only way you can get the maximum from ANY high resolution sensor.

To wit: My first "digital back" was a BetterLight scan back. It was ahead of its time and had a true "live digital focus" capability -- measured per color channel inter-pixel contrast. Anyway, I remember using it on a landscape shot in Yosemite where I had my 210 lens mounted. (The BetterLight had a 75mmx100mm sensor scan area so the 210 was a slight telephoto, like about a 120 in MF parlance.) I used an 8x loupe on the GG to get very close initial focus, then took a scan. I then turned the live focus on and saw I needed to make a small correction -- very small in LF terms -- by tweaking my focus knob approx 0.5mm to get the channels to peak. In the final image comparisons at 100% view, that 0.5mm extension "moved" the exact PoF from the roughly 300 meters distant horizon to the 30 meter distant tree I was actually wanting to focus on. We never had accuracy better than a good loupe with film, and moreover sheet film was never within 0.5mm of flat corner to corner anyway -- it's amazing we ever made any worthwhile images before digital :ROTFL: !

 

[tjv]

I've shot large and medium format film for most of my professional life with many cameras. I have shot the same camera and lenses on my Linhof Techno with both MF film and digital. I learnt very quickly that digital capture stresses the lenses far more than film ever does. With my lenses on MF film, I could go right out to the edge of the IC and see almost no image degradation. Film grain hid a multitude of sins, and looks attractive, even on big prints. With digital I can clearly see when I've missed focus a fraction and when the lenses are stressed, even in moderately sized prints and when shooting at f11. Like it or not – and I don't like it as I was dragged into the digital realm kicking and screaming – things have got more complicated in my transition to digital. I'm not obsessed with achieving perfect everything by any stretch of the imagination, but at the same time I paid a massive chunk of change for my digital gear and I want to get the best out of it or at least equal what I got from what I was using before.

Reading through some of the posts on this thread, I have had those same thoughts.

I was just looking at some of my prints from 4x5 and medium format negatives shot 30-40 years ago and then realized it was sheer luck they turned out as well as they did.

Gary