sinar F1 question

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i am a green user of sinar F1, as it has an angle calculator and DOF calculator, i did try to use them , but i found difficulty in using in Macro setting, Q1/do they applicable in Macro setting? Q2/actually, what will be the procedures in adjusting the movements, such that minimum steps will be attained?according to the instructions of F1, first adjust the tilt, then refocus if necessary, then adjust swing , then refocus if necessary, and finally the DOF knobs, is it correct? thanks

-- benz (wchiping@hotmail.com), March 11, 2002

Question 2 first. You are correct about the procedure, but you can do either the tilt or the swing first as theorder in between the two doesn't matter. Lastly you find the DOF.

Q1: You've probably found that you quickly run out of DOF in the macro range. The DOF calculator does work in the macro range, but there are some things that have to be adjusted. On the other hand this is good news. Say that you are working at 1:1 scale, i.e. you are shooting a 10cm large object to be 10cm on the negative. Say that you might get a f/45 read on the DOF scale. Procede as normal and turn back the focus setting to f/22 and you have the focus plane correctly set. BUT, you don't have to set the aperture to f/45. You can set it to f/22, i.e. 2 f/stops larger than what the indicator says. This makes perfect sense, as the DOF calculator settings are intended for normal, i.e. close to infinity shooting. Comparing the distance from the lens, or rather the aperture opening, to the film plane you'll find that in the 1:1 shot the distance is double compared to infinity setting. As the distance have doubled, the light cone producing the circle of confusion is narrower, allowing you to open up the aperture. An interesting fact is that the adjustment factor for the aperture setting follows the exposure adjustment factor for macro work. (I.e. when shooting 1:1 you have to adjust your exposure by 2 stops, but you need to stop down 2 steps less.) So, for the example given, you measure the exposure to e.g. 1 sec at f/45, without any compensation for the bellows draw. KEEP that exposure, and open up the aperture to f/22.

The "same" information can be found in the Sinar book "Photo Know How".

If this doesn't make sense to you, keep asking... The Sinar is an excellent and quite pedagogic tool, but I'm not sure if the word "simple" really comes to mind when talking about any LF system.

-- Björn Nilsson (b.w.nilsson@telia.com), March 11, 2002.

Hello..

this site http://www.sinarbron.com/123f.htm

may help if you dont'know it yet...

-- dan n. (dan@egmail.com), March 11, 2002.

thanks everybody, actually , i print the article "123 of focussing" in sinar website, and i do it myself, and did encounter the above problems. hi, Björn Nilsson, the book u mentioned, i ve checked in amazon, is it the " photographic know how"by robert darker 1982 edition? as i read the stroebel --view camera technique, just a brief description of angle calculator and DOF calculator , but no detailed illustration.

-- benz (wchiping@hotmail.com), March 11, 2002.

To clarify about the book "Photo Know-How" that I mentioned earlier. It is written by Carl Koch and Jost J. Marchesi ant the copy I have is translated into swedish back in 1986. It is an excersize book which seems to be the foundation material for the courses that Sinar gives on LF in general and Sinar cameras in particular. If you can find it somewhere, perhaps 2'nd hand, go for it. It really helped me and some friends too, to grasp some areas which are tricky.

I looked for it on amazon.com and found nothing, so I guess that the book isn't published anymore. They have other books, the "Creative Large Format" series, which I guess covers the same area. (But I'm not sure, as I havn't actually seen them at the photo store.)

-- Björn Nilsson (b.w.nilsson@telia.com), March 12, 2002.