Time between winds and film path radius are probably the biggest factor for producing a bulge of the film in the film gate. I suspect different bases and the presence of a paper backing contribute more to the between-film variability than the thickness of the emulsion. One of the main reasons I'll pick up the 4x5 camera instead of a MF rollfilm camera is that the 4x5 film usually holds very flat (hasn't bulged on me yet). Whereas with rollfilm this bulging is my nemesis .
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its a great feeling when you recieve a camera in better condition than expected or was discribed, kinda makes up for the groans and disappointments when you recieve a camera with any number of misrepresented problems or just heaps ruff looking.
Originally Posted by 36cm2
the isolettes are popular and for their price (particularly when new) are good value for money, reasonable smooth lines that fit you hand nicely but the quality cant be compared to the perkeo at all. they just feel nice and solid in the hand, quality bellows and a good deal smaller and fit in your pocket .
one thing i would advice with the perkeo II is to get or download the manual and become very familiar with the winding on and double exposure prevention mechanism..practice with it until you know you can do it properly with out fail, every time...many people complain about this mechanism failing or broken but it is almost certainly in 99% of cases because it has been incorrectly used and forced at some point. use it properly and it will never fail...i guess it will at some point--maybe 300 000 exposures
you can fit a filter on and leave it on to close it, though you cant just use just any 32mm filter and do this, many of the commonly available voigtlander 32mm filters wont allow it to close with it on, you would expect them to but they dont! the front side diameter is too large. generally there is not a problem with the added height fitting behind the front door when closed
i cant lay my hands on the exact model numbers and brands of filters that will fit just at the moment (things all over the place here), but i have a few that i know do fit, some zeiss, voigtlander ( i am pretty sure) and some other lesser known brands all work. but you have to try and get the ones that dont have a large diameter on the front side, if they are about 32 diameter on the front they just fit . so you need to ask or you can reasonably expect the should fit if you notice a slight step in (smaller) on the front side diameter compared to the rear which slips over the lens. most you will notice have a larger diameter on the front (a step out) than the rear part that pushes on the lens
That's perfect. I've located the type of filter you're talking about now. Thanks so much again. I read the manual closely by the way. I learned my lesson with these quirky mechanisms many years ago with my Rolleiflex. You have to do the hokey-pokey and the chicken dance simultaneously in order to get the 2.8F to shoot the second half of a 220 roll. Always a pleasure. Thanks to everyone. Time to shoot!
"There is a time and place for all things, the difficulty is to use them only in their proper time and places." -- Robert Henri
i'm curious what camera or system you have have film bulging problems with, I cant say i have had with any (hasselblad for decades, vintage folders, bronica, rb67 etc etc) unless there was something wrong somewhere along the line with the camera or loading film etc. i use large format as well and like for its own added attributes it provides, i also shoot some vintage [camera] formats like 9x12, as an example they need metal film sheaths to take film instead of the dry glass plate they were designed for, before you even begin with these the film is .3mm to .5mm away from where it is supposed to be because of the added film sheath thickness, but this small margin makes no noticeable impact on the end picture (its small error diminished with DOF even wide open and close focus etc).
Originally Posted by ic-racer
i guess where i am going with this is, while that article is interesting i think it has to taken with in its context, reasons behind it and also noted that it is just an article, no proof was given (results hadnt been done), only speculation really and no follow on have i seen from that article nearly ten years ago (less of a need to now perhaps because sensors are obviously flat and not an unknown quantity once inside the camera as film is, or the results really didn't matter or show any noticeable effect!) . in addition there are other reasons given for unsharp pictures such as camera shake (no doubt one of, if not the major contributor to unsharp pictures (on a day to day real life basis) and so on.
they are talking about a testing machine to measure film curvature down to the millionth's of a mm, no doubt zeiss would find this information useful in the lens design and production business because they would want to understand how much unsharpness is attributed to their lens and how much can be shifted to the film as a cause of unsharpness, something that they would of had difficulty measuring before. it should also be noted that they are testing the film using very fast modern multi element medium format lenses (wide through to tele f4/350 etc) and the article makes the point that at these extreme wide open limits, is where these sorts of unsharp errors may show up.
this sort of high performance is not really a factor with 120 roll film folding cameras, the lenses are no faster than f2.8 at 75mm -80mm and about f3.5/105mm for a 6x9 folder, DOF should easily cover up any minute problems with film curvature.
still, it was an interesting article, the time theory is interesting but if they are going to be scientific about it then other factors such as temperature etc would all factor into it as well i would think, it may also not be as relavent to a vintage folder compared to a compact modern roll film back considering the folding camera in some cases will be a longer base dimension/not as sharp bends in film. just a thought
i am not saying it is the ideal format, it is what is it is...its not bad though considering its stood the real test of time ..years of production
Last edited by Anastigmatic; 04-22-2009 at 11:16 PM. Click to view previous post history.
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