Page 2 of 4 FirstFirst 1234 LastLast
Results 11 to 20 of 34

Thread: Rodenstock Depth of Field / Tilt/ etc/ calculator gizmo?

  1. #11

    Rodenstock Depth of Field / Tilt/ etc/ calculator gizmo?

    O.K., Calumet carried it, it was made by Horseman and it cost $74.99. Catalog # HR1015 in the 95-96 catalog. It was called the photo angle finder and was accurate to within 1/2 degree. It's not listed in the more recent Calumet catalog and the B&H Professional Photo Source book has it listed as discontinued.

    The one I got from True Value was $9.49, not $5.00. At those prices, no wonder Horseman discontinued it.

  2. #12

    Rodenstock Depth of Field / Tilt/ etc/ calculator gizmo?

    RE: "Do you know of a cheap and small level I can buy that will read to within 1 degree increments?"

    Horseman made a wonderful Photo Angle Finder (wasn't so inexpensive, but accuracy and precision rarely comes at low cost). It even had a mirror behind the needle so you could read it with consistent accuracy. In their infinite wisdom, they came out with a new version of the Photo Angle Finder, and replaced it with a nearly worthless (IMHO) hunk of plastic with less accuracy and more difficult to use.

    I've also used the Rodenstock calculator, and find it an OK tool in a limited way. I wish I knew some of the assumptions it has built in like the circle of confusion for different formats. I find the Depth of Field side of the calculator more useful than the Scheimpflug calculator side. I've rarely been happy with the tilt angles it calculates and ultimately find trial and error easier, more accurate and faster. At best, the tilt angles are a starting point.

  3. #13

    Rodenstock Depth of Field / Tilt/ etc/ calculator gizmo?

    I have this calculator too. I completely agree with Larry. I think Ellis is looking for a calculator for his DLC.

    The depth of field side is more useful than the opposite side for angle finding. It is because you need to know <ul> <li>the angle &Alpha between the optical axis and the monorail <li>the vertica distance (horizontal distance for swing) on the ground glass between any two points on the focus plane <li>the angle &Beta between the optical axis and the desired focus plane </ul> And finally you get the tilt angle &Gamma on your camera. It's much faster to figure out &Gamma using try and error with educated guess work by yourself. All we want to know after all is &Gamma. If we can figure out it, why care about especially &Beta (&Alpha is useful to determine the depth of field necessary)? Above all, it looks like the calculation for &Beta is designed for a camera with center tilt. Somebody any comment?

    Depth of field side is useful because Linhof DOF table does not include &Alpha (i.e. &Alpha = 0; optical axis and monorail are parallel) or bellows extension factor (I have to check...). But of course if you set them parallel most of the time, I think you can fix the &Alpha dial at 0 degree by tape. IMO, the combination of Linhof DOF table and a list of Bellows extension factor for each of your lens is much quicker assuming you use &Alpha = 0 most of the time.

  4. #14

    Rodenstock Depth of Field / Tilt/ etc/ calculator gizmo?

    iCorrection for the above comment: Above all, it looks like the calculation for &Beta is designed for a camera with center tilt. I wanted to say &Gamma, not &Beta.

  5. #15

    Join Date
    Jan 1999
    Posts
    94

    Rodenstock Depth of Field / Tilt/ etc/ calculator gizmo?

    I have seen a lot of levels at many stores including the large Tru-Value HD store across my home. Interesting that you have found a cheap 2" level that reads to one degree accurately!!! I must be really missing something here because I don't think that is physically possible. Does it have a magnifier so you can see where the pointer is lined up? or is it one of those bubble levels with graduations that are very limited in the angular range they can measure?

    BTW, everyone talks about tilt. How about SWING? Any bright ideas?

  6. #16

    Rodenstock Depth of Field / Tilt/ etc/ calculator gizmo?

    The company that made the circular angle finder I have is named Johnson. The price sticker says ServiStar. The package reads:

    "Precision Angle Locator Measures angles instantly and accurtely from 0 deg to 90 deg ina nay quadrant. Accurate leveling and transferring of angles on any surface. Includes conversion chart for pitch per inch and pitche per foot."

    Electrical Conduit

    Machinery set-up

    Pitch or slope

    Roof construction

    The device itself is black with a clear circular guage calibrated in degrees from 0 to 90 four times with larger hash marks every 10 and dots at key points 45 deg, 90 deg, etc. The circular dial is 3" across. There are two flat surfaces for setting the guage down on the surface you're measuring, one is 2" and 3.5" long.

    As I said, it is calibrated in individual degrees but they are tiny and require you to hold it steady and look closely. I got it in case I'd need it and out of protest against the high price tag of the Horseman unit. So far an occassion for it's use has not occured.

    Johnson's address on the back is Johnson Level & Tool Manufacturing Co. Inc. 6333 W. Donges Bay Road Mequon, WI 53092-4456 USA

    I imagine you could find 'em in the ThomCat Register.

    If accuracy is essential, why not get a SINAR or a Linhof or other camera with swing and tilt scales calibrated in degrees?

  7. #17

    Rodenstock Depth of Field / Tilt/ etc/ calculator gizmo?

    RE: "BTW, everyone talks about tilt. How about SWING? Any bright ideas?"

    Why yes! Assuming you camera doesn't have any steel (which the Canham DLC doesn't to my knowledge), you can use a common magnetic compass. Measure before swinging, move the compass dial the number of degrees you desire, and swing the lens until your aligned back to north. The higher quality camping compasses will allow about 1 degree accuracy (some even have a built-in magnifier where you read the dial). For now, forget digital compasses. Their accuracy seems less than standard compasses.

  8. #18

    Join Date
    Jan 1999
    Posts
    94

    Rodenstock Depth of Field / Tilt/ etc/ calculator gizmo?

    Larry, YES! Why didn't I think about that?!

  9. #19

    Rodenstock Depth of Field / Tilt/ etc/ calculator gizmo?

    Carlos,

    My Boy Scout compass is 1.5" across the dial and it's calibrated in 1 degree increments around the full 360 degrees. Is that physically possible? I'd think gravity was just as reliable as magnetism.

  10. #20

    Rodenstock Depth of Field / Tilt/ etc/ calculator gizmo?

    As for addressing the "how to find the angle of the plane of sharp focus" Well this to me is the most critical part of lens tilt. If you have that, you can then estimate the distance the plane of sharp focus interesects below the lens, then you only need to glance at a look up table (cheat aheet) to determine the tilt angle. You can sketch it out to be sure, some quick geometry. I use a Clinometer, with a sight scope in it, it tells you from where you are standing the height of an object and its angle. It is the size of a pack of matches. But I must admit, I carry a TI - 89 calc. with me anyway, it has the most amazing numeric solver program in it. You load an equation with all it varialbes, then enter all what each varialbe equals, and solve for the missing one. The beauty is, it does not matter which variable you are missing, it solves it with out you having to re write the equation for the missing variable... they are $159 at any office max.

Similar Threads

  1. Depth of Field, Depth of Focus, and Film Flatness
    By steve simmons in forum Cameras & Camera Accessories
    Replies: 65
    Last Post: 7-Jan-2006, 19:30
  2. front tilt and depth of field (WYSIWYG) ?
    By adrian tyler in forum Style & Technique
    Replies: 10
    Last Post: 29-May-2004, 19:22
  3. Replies: 3
    Last Post: 10-Mar-2004, 10:14
  4. Rodenstock calculator
    By Josh Divack in forum Gear
    Replies: 13
    Last Post: 25-Jan-2004, 15:01
  5. Replies: 5
    Last Post: 2-Jul-2001, 16:49

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •