Purely Theoretical Musings on Resolutions and Formats...

[ic-racer]

that implies that the greater the magnification, the worse the quality. but i have found that not to be true with my 50mm minolta enlarger. it seems to be designed for big enlargement (>10x) and if you do a small 5x enlargement, the quality is terrible. my EL-Nikkor is the opposite and 5-10x enlargement seems to be the sweet spot. Here, I can get maximal sharpness at f/5.6 or even f/4, extremely sharp from corner to corner. I would say that this $40 enlarger lens is optically perfect. However, if I go smaller than 5x, the quality actually goes down.

good enlargers with modern lenses are much cheaper than drum scanners, or even consumer scanners. they are being dumped everywhere for $10. scanners tend to have trouble if the detail on the film is too dense.

I can share many of your expierences with those lenses and ones similar (like the Minolta 30mm) and those are good points. I actually was hinting more to the fact that when enlarging Minox to 16x20, a few micrometers of buckle can spoil things, while I suspect I could easily tolerate a whole millimeter of buckle or mis-alignment when enlarging 8x10 negatives to 16x20.

Now that I think of it there is ONE thing that is better when enlarging the mini negative. That is 'evenness of illumination.' I think it is more of a engineering challange to make big enlarger light sources that have even illumination.

[sanking]

Hi,

the 110 lp/mm on 6x7 format with a standard 100 film, was that lines per mm or line pairs per mm i.e. if it was line pairs that would mean 220 lines per mm .. sorry for asking this so lately in this discussion.

Joerg

It was not my study but I am pretty sure that the resolution values were given in lines per millimeter, not line pairs per millimeter.


Sandy King

[tjvitale]

Where do you see those Nikon claims for 5000 lp/mm?

[cotdt]

Where do you see those Nikon claims for 5000 lp/mm?

somewhere on the nikon industrial lenses website, but i can't find the link anymore. they are the lenses used to make your computer chip, so very very high resolutions are needed. these lenses cost millions of dollars each. i would love to own one.

[Robert A. Zeichner]

Here is a link to the Zeiss site in which their micro chip lithography optics are described:

http://www.smt.zeiss.com/C12567B0003...256D580037B4B1

[Ken Lee]

Medium format is vexing. The cameras are certainly more portable than LF cameras, but it seems to me that unlike View Cameras, nobody every came up with an optimal design.

Those fabulous Mamiya results presume no cropping, and a steady tripod with cable release or self-timer. The camera is lighter than a view camera, but then again, it's got a limited focusing range. And... it's a rangefinder. And it's roll-film. You have to develop all the shots together, so forget about DBI, BTZS, etc.

Once you start cropping those MF images, the number of lines per millimeter starts to slip, and your blood pressure starts to rise commensurately. "I spent $2k to get a decent scanner for this thing... but I'm still tossing data away ?".

Or... you could get a nice cheap 4x5 or 5x7 with a merely OK lens, and with the same tripod and cable release, you get to use an infinite variety of lenses, with no limit on focusing range and parallax-free viewing. You also get to use an affordable scanner, and develop the negatives individually or together... etc.

I have 3 medium format folding cameras from the 1950's. I love them, but I don't try to squeeze every micron of data out of them. They fit in the pocket, and are good enough to make nice grainless 11x14 images. For serious work, I use a View Camera.

[Nathan Potter]

The issue of resolution comparing medium format to large format has been touched on in other threads. I would add to Kens' comments above by saying that the swing and tilt ability of a view camera allows one to make use of the Schiempflug relationship by keeping an extended subject field in critical focus whereas a fixed film plane will have to rely on the hyperfocal lens setting at an undesirably high f/no for extended depth of field. Resolution is degraded to a series of circles of confusions away from the actual film focus point (airy disc) by stopping down the lens of a fixed image plane camera (not to mention creeping diffraction effects). In practical photographic situations one usually is faced with depth of field situations and the flexibility of the view camera seems unsurpassed.

Nate Potter, Austin TX.

[sanking]

Ken,

No way to compare Mamiya 7 to medium format folders from the 50s. Resolution of Mamiya 7 is way beyond the capability of the old folders.

If Leica is an optimal design for 35mm, as many people believe, then Mamiya 7 is an optimal design for medium format,IMO. No, compared to view cameras there is no close focus, no perspective control, and no shift and tilt to control plane of focus. That said, my personal belief is that in the majority of typical landscape scenes Mamiya 7 can equal or beat 4X5 performance on the negative and at the same print size.

But, as we have discussed before, in order to pull all of the detail out of a Mamiya 7 negative, and make it competitive with 4X5, a drum scan is necessary. Even a dedicated film scanner like the Nikon 9000 leaves a lot of detail on the table when scanning well-exposed Mamiya 7 negatives and transparencies.

Sandy King

[cotdt]

But in any event, TechPan is no more. So what other films like it are available in MF or LF? Just in case I might want to send some of my negatives off to Lenny Eiger to have scanned on his Azteck Premier at 8000 spi? I am curious about the limits of quality.

Sandy King

Hi Sandy, for MF the Rollei Pan 25 is very similar to the old TechPan:

http://www.freestylephoto.biz/sc_pro...pid=1000001679

Should allow for massive enlargements, but for normal contrast you need the same kind of special microfilm developer that TechPan used, such as Technidol or something similar like this:

http://www.freestylephoto.biz/sc_pro...pid=1000002500

If you go for it, please keep us informed with your results!

[sanking]

In a previous message I wrote, "my personal belief is that in the majority of typical landscape scenes Mamiya 7 can equal or beat 4X5 performance on the negative and at the same print size." Majority may push the envelope just a bit much, so I would amend this to Mamiya 7 in 6X7 cm format can equal or beat 4X5 with many typical landscape scenes. 4X5 is clearly a more flexible system and there are situations where the use of swings and tilts is crucial to getting adequate depth of field without closing down the lens too far.

If movements are not required I am pretty sure that if we only consider resolution Mamiya 7 can virtually always equal 4X5. The optics of Mamiya 7 system are sharper, and this fact, together with the relatively small difference in magnification factor of a 6
X7 cm negative compared to 4X5, pretty much equals out the two formats. In terms of tonal values I believe one will need to use a slower film (finer grain) in 6X7mm to match 4X5 in any size larger than about 11X14.

Sandy King