Archived posting to the Leica Users Group, 2000/03/18
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]> > Thanks, I understand the issue, and the overall issue is separate from > > Irwin's comments. I know Robert's site well, in fact, I am referenced a > > number of times on it. > I couldn't find the references to "Franklin". Which ones were they? Well, then you ought to look more. Without much effort, I found ten separate references to my name on his site. If you truly can't find them, I will provide them for you if you email me privately. > > The original post specifically mentioned Hasselblad. There is ONE vague > > comment in your reference, referencing Hasselblad, that 'some people' > > (unqualified) 'wait' for the film to settle after winding the film. > I found 3 items referencing "Hasselblad". There were many more (including a > flatness table) that referenced "2 1/4 SLRs". Actually, there were a total of four. Only one of them had anything to DO with a Hasselblad and film flatness, the second one was referenced in a section on focusing accuracy, and as such, not pertinent to this discussion. The other two were part of the email address for the Hasselblad users group, hardly pertinent at all. > Do you think Hasselblad should be excluded from the latter category? It depends on whether it's relevant to the discussion at hand or not. > Note: The references to "Hasselblad" you mentioned is quoted in its entirety > below: > "Persons using Hasselblad film backs, in which the film curves twice around > the back, have experienced problems with film buckling right after the film > was advanced. Let the film sit for awhile, and the film "relaxes" and > flattens out, producing a better and sharper on film image" > It doesn't sound vague to me. There are elements of scientific analysis, and as such, the claim above is vague, at best. By any stretch of science, this reference is unsubstantiated, and it is vague because it provides NO description of any tests, or any data from any tests, or even a source for the referenced ' claim'. > > The conclusion is pure speculation, since there is no reference to anyone > > actually measuring the effect of 'waiting', and mechanically, I find the > > assertion unwarranted. > Have you measured it? > What were your results? No, I have no need to measure it, until I find there is a need to measure it. A need to measure it will come when I discover there is reason to suspect film flatness is a possible 'problem', and to date, I have not seen any problem in any of my tens of thousands of Hasselblad negatives that would at all relate to film flatness. I also never said it wasn't a 'problem' for anyone else, all I said is I have never seen the problem, nor have I heard any one Hasselblad user (or non Hasselblad MF user for that matter), bring this issue up as a problem they have had, in the 20 years I have been doing professional photography. I have heard it as a problem with LF cameras though. If I haven't had any problem believed caused by this 'phenomenon', therefore I would have no cause to explore it's cause. In fact, a case could be made that the film curls AFTER being unrolled, and giving it time to 'settle' might, in fact, make the 'phenomenon' worse. I am not making that claim, but without a controlled experiment, there is no evidence. Overall, I just don't believe it's a problem. > >I don't like to deal > > in speculation and the ethereal when claims like this are made. > The reference and its measurements are neither speculative nor ethereal. The reference does not contain any actual measurements, and as such, with no supportive data, is purely speculative. Please look up the word 'speculate'. It means (OED): "form a theory without a firm factual basis" And given there was NO actual test or test data cited (ie, factual basis), just a 'theory', that IS speculation. > Would you care to share your more concrete observations with us? I am sure that it (and almost anything else for that matter) can be made to BE an issue, but in %99.999 of the photography that Hasselblads and Leicas are used for, as designed, this just isn't an issue anyone needs to worry about, unless ones cameras is just plain broken. >Some of us are keenly interested in this topic! Why? Is it just the theory that you are interested in, or has anyone actually HAD a problem that (they believe) has been caused by this phenomenon?