p._aing

Without more details, I agree that it's likely techniques as Chun In Martinez said. The theoretical argument of "larger format=less resolution on the film" doesn't seem to hold here. f=28mm for 35mm format is wide angle. f=80mm for 6x6 is about normal angle. Roughly speaking, a 80mm lens for 6x6 may not be as difficult to design and manufacture as a 28mm lens for 35mm. Without any real figures, it is a quite evasive discussion. But aren't lens for Hasselblad supposedly made almost regardless of price/value consideration, I mean low compromise in manufacturing tolerance...?

How does the english pronunciation of Mamiya sound like ?

I process B&W 4x5" sheet in trays, up to 7 with the shuffle method.

I have a few time noticed big dust spec. that seem to be sticked to the emulsion. Last time, I noticed such an inclusion on a still wet sheet, on the last wetting agent bath and I couldn't remove it by gently rubbing. It eventuelly got off with scrathing but so did the emulsion. The sheets were pre-soaked before developping and they came out fairly well exposed/developped.

 

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Thanks for any hint or suggestions.

Just a comment slightly out of topic.

 

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Chris Kordzik : "exposures of 1/500s on the same frame, utilising a ND 1.0 (filter factor 10x) neutral density filter, which would give me the effective exposure of 1/5000s....an ultrashort exposure of 1/5000s without a color shift...reciprocity failure effects only at around 1/10000s"

 

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I think that, for a single exposure, reciprocity failure depends on the actual duration of the exposure, that is, 1/500s. No need to worry at all. You could close down the aperture by a number a stop (-3.3 ?) equivalent to that of this ND filter to have the same exposure.

Why not LF ? Sure you need to recock the shutter. But with a good tripod and head, you can minimize re-positionning problem. Most of all, the much larger flm size means that sharpness isn't that critical so that a little blur could be acceptable. If there is no static subject in your final film such as buildings or mountains, you will not see repositionning inaccuracy problems due to recocking the shutter.

From Mel Brown : "In analog (film) photography, each grain has the capacity to record a near infinite number of tones."

 

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Can you confirm ? If memory does not fail me, I think I read in "Basic Photographic Material and Process"(Leslie Stroebel,et.al), that each grain has no tone at all. When an unexposed grain receives enough light, it changes to exposed state. The "enough" has probabilistic/statistical meaning : the chance for the grain to switch is a probability A depending on the intensity of the light. In other words, if a large area receives an even illumination, some grain are exposed, others are not; the proportion of grain which are exposed is the same the aforementionned probability A.

 

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Maybe I am not 100% correct and oversimplified the physics but it seems consistent with observation. When the magnification is low, as in LF, we see an average grey and smooth change in tones with change of that light intensity. With high magnification, we can see grain (or holes) in textureless evenly illuminated areas of the print which are not all black (no grain exposed) or all white (all grain exposed).

Tetanal have a reversal which can be used for developping normal B&W negative into slides, or getting B&W prints from slides. Haven't tried yet however but it might work better than conventionnal reversal process for color slide.

I also had some focuring problem with my M7/150mm. After lookink at the slides with a high power loupe, focus was consistenly closer than what the subject I aimed. Not so visible at long focusing distance with the lens well stopped down, but a definite problem for closer subject (<20m) at f/8. I brought it to Mamiya (Japan, in Tokyo) and they checked and adjusted everything in 30min, free of charge. They told me however not to use the camera for one day because of some joint hardening issue in the rangefinder.

In addition to the last answer : I guess the subject is likely to move (or close his eye, or lightly change his expression...) after seeing the flash, believing that the photo is taken.

2nd curtain sync. seems better for me.

It is tough enough to be used with the Toyo45A, a large format camera, with 300mm lens. The weight of the LF/300mm (3kg) is well balanced, almost centered on the tripod. A sturdy tripod head is also necessary.

For 6x7 coverage, there is not much choice, Kenko and Peak, both with low magnification. The Kenko x3.6 is a good quality loupe. For full coverage, you don't need any higher magnification because the field of view will become too large for the human eye.

I also use a x20 Hakuba (maybe different brand name outside Japan) loupe for looking at small details and judging sharpness.

My slides come in a sleeves with two slides per row (5 rows) and my light box is wide enough for evaluating one row each time. I just have to shift the sleeves vertically.

I have that Kenko x3 loupe. It is very nice and you can adjust focus which is useful if you have little dioptric correction. Even if you dont need correction, you need to adjust it correctly to have a sharp image from corner to corner. With a 6x7, the field of view is so large that I have to "move" my eye to see the whole slide. It's like watching at a projection screen from a very close distance. I guess that with a larger magnification loupe (with full 6x7 size), this effect would be even more important.

I am interrested in MF for landscape photography and 6x9 format more interresting than 6x7 especially. Moreover, film processing and full frame printing is easily available where I live. Lightweight is an issue, so no MF SLR, only rangefinder. However I only know about the Fuji GWS690. Are there any other 6x9 rangefinder ? The Mamiya 7, though 6x7 format, has built-in meter and interchangeable lenses that are supposedly state-of-the-art. How do the 65 or 80mm lenses compare with the lens of the GSW690 ?

Thanks.

To Paul :

A very good (maybe best) heavy duty backpack is the North Face "Snow Leopard". It is like a big backpack, 70 l, with top opening but it also has two lateral big zip on the two sides so that you can easily reach anything in the bag. It also has two side pocket that can be opened when you are carrying the backpack and it has a very large comfortable hip belt.