If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#11
|
|||
|
|||
zone system test with filter on lens?
Phil Lamerton wrote:
Since I will eventually be using the camera in the portrait studio with a yellow/green filter, would it be wrong to do the testing with the filter over the lens? Remember that you need a spot meter capable of reading flash light (not every meter can do it) if you intend to use ZS in studio with normal eletronic flashes. ZS is of quite limited use with an incident flash meter. Severi S. |
#12
|
|||
|
|||
zone system test with filter on lens?
What 'camera and lenses'? Koni Rapid Omega with 90mm and 180mm lenses. I'm uncertain as to why you should ask this? rgds, phil lamerton |
#13
|
|||
|
|||
zone system test with filter on lens?
Severi Salminen wrote in message ...
Michael Scarpitti wrote: Since I will eventually be using the camera in the portrait studio with a yellow/green filter, would it be wrong to do the testing with the filter over the lens? What 'camera and lenses'? How would it affect your answer if you knew the camera and lens in question? Most filters work quite similarly no matter what camera or lens... It matters a great deal. Is this medium format? Large format? 35mm? |
#15
|
|||
|
|||
zone system test with filter on lens?
Severi Salminen wrote:
: Michael Scarpitti wrote: : What 'camera and lenses'? : : How would it affect your answer if you knew the camera and lens in : question? Most filters work quite similarly no matter what camera or lens... : : It matters a great deal. Is this medium format? Large format? 35mm? : Umm, how does it matter? Does light behave differently between various : formats? Does a certain filter affect light differently on different : camera body? : Let me ask like this: : 1. Would it be wrong to do the testing with the filter over the lens : using (35mm) Canon EOS 30 with a 50mm f/1.8 lens? : 2. Would it be wrong to do the testing with the filter over the lens : using (6x7) Mamiya RB 67 Pro-S with a 180mm f/4.5 lens? : 3. Would it be wrong to do the testing with the filter over the lens : using (4"x5") Toyo Field 45AII with a Schneider 150mm f/5.6 lens? : How would the answers now differ? In what cases it _IS_ wrong to do the : testing with filter in place? And why is it wrong? I'm just curious to know. It would be wrong for you to use any camera but a leica. -- Keep working millions on welfare depend on you ------------------- |
#16
|
|||
|
|||
zone system test with filter on lens?
|
#17
|
|||
|
|||
zone system test with filter on lens?
Michael Scarpitti wrote:
1. First of all, because zs is unsuited to roll film. Actually ZS is very usable with roll films. There are of course some limitations as per frame development is quite difficult to do but ZS can be used (at least to some extent) with roll film cameras. And in studio environment (as in Phil's case) it is quite easy to have and change different backs/rolls for different development times. But Phil obviously didn't ask if ZS is suitable or not, but about using a filter when testing. 2. Because some cameras have the shutters in the lenses, and thus each lens has to be calibrated. But that has nothing to do with Phil's question about testing with filter in place. It doesn't even matter if one uses ZS or not: the photographer should allways know the accuracy of his/her shutters. Otherewise it is quite hard to make correct exposure with _any_ technique. Focal plane shutter is not allways a solution as aperture blades/scale can also be a bit off. So some basic testing is allways beneficial. 3. Because leaf shutters are less efficient at high shutter speeds and large apertures. Electronic flash is so quick that this does not matter, and thus your exposure will not be the same. That is true - allthough the difference might or might not be of any importance. But that is a phenomenon that must be considered allways. Phil asked only about testing with/without a filter - which you didn't even bother to answer Regrads Severi Salminen |
#18
|
|||
|
|||
zone system test with filter on lens?
Thanks very much for all the advice.
Please could anybody clarify something? If I calculate my film speed and development time for N outdoors, with the filter in place (and for each of my lenses), how different are the results likely to be from those of the same test conducted indoors using electronic flash lighting? Also, in studio portraiture I am unlikely to place any essential part of the image on the toes region of the film's characteristic curve. Doesn't this mean I could safely use the film speed determined in my outdoor test? TIA - phil lamerton |
#19
|
|||
|
|||
zone system test with filter on lens?
Severi Salminen wrote in message ...
Michael Scarpitti wrote: 1. First of all, because zs is unsuited to roll film. Actually ZS is very usable with roll films. There are of course some limitations as per frame development is quite difficult to do but ZS can be used (at least to some extent) with roll film cameras. And in studio environment (as in Phil's case) it is quite easy to have and change different backs/rolls for different development times. But Phil obviously didn't ask if ZS is suitable or not, but about using a filter when testing. 2. Because some cameras have the shutters in the lenses, and thus each lens has to be calibrated. But that has nothing to do with Phil's question about testing with filter in place. It doesn't even matter if one uses ZS or not: the photographer should allways know the accuracy of his/her shutters. Otherewise it is quite hard to make correct exposure with _any_ technique. Focal plane shutter is not allways a solution as aperture blades/scale can also be a bit off. So some basic testing is allways beneficial. 3. Because leaf shutters are less efficient at high shutter speeds and large apertures. Electronic flash is so quick that this does not matter, and thus your exposure will not be the same. That is true - allthough the difference might or might not be of any importance. But that is a phenomenon that must be considered allways. Phil asked only about testing with/without a filter - which you didn't even bother to answer The filter bit is actually irrelevant, or at best, the least of his worries, but he was unaware that these other issues will mess up his measurements completely. Why? 1. An electronic flash exposure make with a leaf shutter does not suffer from inefficiency. All shutter speeds will give the same exposure (not counting ambient light) with electronic flash. Existing-light exposures made with different combinations of apertures and shutter speeds, using a leaf shutter, will not be equivalent, because slow speeds and small apertures will give more total exposure than the nominally equivalent exposure with large apertures and high shutter speeds. 2. A certain amount of reciprocity failure is possible with electronic flash, the duration of which is often much less than daylight exposures. Regrads Severi Salminen |
#20
|
|||
|
|||
zone system test with filter on lens?
|
Thread Tools | |
Display Modes | |
|
|