![]() The "Farthest" anlge plane is far in angle sense. When tilt/swing, then focus on the two farthest angle planes from the optimum plane of focus or two objects on the corresponding to which intersect the corresponding planes of focus.(the plane of focus is vertical to optical axis) When no tilt/swing then focus on farthest and nearest you want in focus, using rear focusing knob.When you use tilt/swing, the way you determine the DOF using the knob is different from the way you'd do with no tilt/swing. The DOF knob is still good in approximation even when standards are tilted/swung so you can still use the DOF knob. ![]() To convert the bellows extension to stops, use one of the methods described in the Bellows extension exposure compensation. But of course you need to compensate exposure time for the bellows extension so use the delta/2 position of the rear frame to figure out the extra stops to be added to time. Notice this equation is the same as N = delta/2/c/(1+m) when m = 0. So you're guaranteed to have the required depth of field at any magnification for a given delta, using the earlier formula: N = delta/2/c. You need to use a more accurate formula: N = delta/2/c/(1+m) but notice the minimum f-stop N for the required depth of field decreases as magnification m increases. Note: the above calculation does not take magnification m into account as Sinar doesn't (but supplemented by another knob). Caution: Because the size of the two knobs are different (tension control knob being bigger than focusing knob), carefully transfer the mark on the focusing knob to the tension knob at the same angle.You now have a Sinar equivalent DOF knob.Mark a line somewhere by a marker on the left side of the focusing knob to indicate where you start focusing and to align the f-number N = 0 on the tension knob to the line on the focusing knob. ![]() Mark f-numbers N's on the left side of the tape, based on N = delta/2/c for a given delta.You now transfered 1 mm marks on the tension knob. When you do this angle transfer, make sure you look directly down to marks. After you transfer the delta to turn on the focusing knob, carefully transfer the 1 mm marks on the focusing knob (angles) to the tension knob.Mark every 1 mm delta for example on the left side of the focusing tape. Convert the distance on the rail to turns on the knob by simply turning the knob and looking at the calibrated scale on the rail.Make sure the tension control knob right next to the focusing knob is relatively tight enough to minimize back lash (maybe not that much even when tension is loose). Tape on both the rear function carrier tension control knob for focusing and focusing knob.Then use the equation delta = 2*c*N to get the minimum f-number N to cover the depth of field required, where c is circle of confusion you want depending on the choice of your format and how much you want to enlarge. Figure out the distance on the rail per turn of the focusing knob, or distance/turn where delta is depth of focus. You could try to make a Sinar equivalent DOF scale on your rear function carrier focusing knob and tension control knob. Steve, I'm one of those people who need brain.But here is worth a try. I've never used it to determine tilt or swing angles. The Dof scale on my Sinar C (which was a hybrid of a Sinar F front standard and a P rear standard.) You then divide the distance between the two points in half (there is also a scale in cm) and drive the function carrier back to that halfway point (let's say theĭistance between the two points is 2.6cm, you then focus back till the distance is 1.3cm) (all of this is much easier done than described). you then look at the scale for the format you are using and decide what size circle of confusion you want to work with (there are two scales for eachįormat 1:4 (or close-up) or infinity (general work) you read the f-stop against the marker line and that is the f-stop you'll need for the depth of field you want. A geared arm shoots forward and makes contact with the back of the functionĬarrier. The rear function carrier forward and push a button on the side of the brainbox. You then focus to your far point by driving You focus on the nearest point you want in focus and slide the brainbox up to the back of the rear function carrier. It is very convient: it slides onto the rail behind the rear standard/ function carrier. You can find one then yes I think it is worth it. ![]() Supposedly the design is being revamped and updated. I am told by the factory that i bought the last "Brainbox" in the US.
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