This was going to be a simple question: What is the name & catalog number of the Rodenstock Depth of Field/Tilt/etc. calculator gizmo?
But I've decided to complicate it. Has anybody actually used this gizmo and does it work and how well does it really work? Thanks for your help!
Ellis, go to the technique category and find the thread called Depth of Field Calculators/Aids. The poster there has used it and was not particularly impressed.
Funny how opinions vary.
Bob Wheeler in his comparison of calculators likes it. Pop Photo likes it, We have had no complaints about it. But not everyone will like everything.
The catalog number is 260700 and it is the Rodenstock Calculator.
Re-reading the poster's comments was that he found it confusing.
Of course each step on the calculator is numbered and you simply follow steps 1 to 4 to set it up for depth of field and pointer 5 gives f stop and pointer 6 the exposure correction.
That is a bit complicated I suppose.
Steps 1 to 4 are:
1 Is the camera tilted and, if so, how much? 2 Format being used between 35mm and 4x5 3 Reproduction scale you are shooting at 4 Distance on the focusing rail between the near and far point (a MM scale is on the calculator to determine this)
Sounds as complicated as the poster stated?
The other side of the calculator is equally complicated as it computes Scheimpflug.
Again by following numbered steps. But this time there are fewer. 5 steps. 1 to 3 to set up the calculator and 4 and 5 to read it.
1 Is the camera level or inclined and, if so, how much? 2 Distance between the near and far points on the ground glass 3 Distance between the near and far points on the focusing rail
4 What was the angle in step 1 above? 5 Read the required tilt angle against scale in step 4
That is exactly how "complicated" the use of this calculator is in operation.
Every step on both sides is clearly numbered. It isn't very difficult.
Sorry a major correction.
The calculator is for formats from 35mm to 8x10" not to 4x5" as I stated earlier.
I have the calculator, and use it. I do find it to be confusing and I occasionally have to refer to the instructions printed on it. However, I view this difficulty as the trade-off for having this information available in such a small and durable device.
One thing I wonder about is how does one exactly know what the incline angle of the rail is or the incline of the focusing plane? My ballhead (Linhof 3) certainly doesn't have any markings on it, and to compute the incline of the focusing plane, you'd need some rangefinder device to measure distances precisely and then compute the angles with an electronic calculator. Furthermore, if you carry an electonic calculator, you may as well program the DOF formulas into it and compute it directly.
Weeeelllll, I'm not taking sides mind you, but if you don't mind spending $5.00 and carrying maybe .6 pound extra, you could stop by the hardware store and buy a circular angle level and butt that up against the g.g. to determine the angle off of plumb of the camera.
Or, you could use your mental protractor and estimate. 90 degrees is pretty obvious. 45 is half that, 22.5 is half that and 11.25 is half that.....
5 degrees of tilt is not negligible in many cases. However, I definitely cannot estimate the 5 degrees ... Do you know of a cheap and small level I can buy that will read to within 1 degree increments?
Like I said, go to the hardware store and pick one up. I think mine cost about $5.00 from True Value. It's 2" on a side and reads in 1 deg increments all the way around. The hash marks are teeny-tiny but they're there.
Calumet used to sell a similar device for $70.00 (=/-) and recently a kit from one of the photo suppliers came up for auction on E-bay. it had an angle finder and bellows extension "calculator" in one nice flat light kit.
Personlly, I don't see why one couldn't use their eyes on the ground glass and Polaroid. Folks have been doing it that way, and without Polaroid long enough, Heaven knows.
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