Parallel back to parallel wall -- how do you know? OK, can't see this on old posts. I was shooting a window, I was parallel (back standard to wall in front) -- well now I suppose just a bit off. I can't see that close on the line on the ground glass. Is there something as objective as a bubble level for knowing you are parallel? Measuring tapes wouldn't tell you because the camera is only a foot wide. Maybe an orienteering compass? There must be a way? Thanks Dean

-- Dean Lastoria (dvlastor@sfu.ca), August 17, 2000

Answers

If you're not parallel, the horizontal lines of the building will converge. So rotate the camera until the horizontal lines are exactly parallel. Of course, you'll need a grid screen.

-- Stewart Ethier (s_ethier@parkcity.net), August 18, 2000.

First you must accurately level your tripod or use a tripod with a leveling base. Then you accurately level your camera. If your built- in levels aren't that accurate, use an external level like the Horseman. Pan around a bit to make sure your camera stays level as you move it. Pick a horizontal element(s) of the building (trim, windows, etc.) which you believe to be level. Then watch the horizontal lines on the ground glass (with a loupe if necessary) as you pan the camera to see when they line up with a horizontal grid line. Of course, it helps if the grid lines on the ground glass are actually parallel to each other and aligned with the camera.

Using a compass is also possible when no horizontal "clues" are present. Accurate compasses (e.g. Suunto Tamdem) are *very* sensitive to nearby metal so be careful. There can be lots of metal in walls (studs, nails, wires, rebar, etc.), and maybe some in your camera. Also, interior walls in particular aren't very flat and can vary quite a bit from one spot to the next. To get around these problems, I've used a spacer (e.g. books, boxes, etc.) to measure the orientation of the wall about 8 - 12 inches away from the wall. The longer the spacer, the more it will average out local variations in the wall surface. I rarely have to use the compass method, and have never thought it as accurate as the first technique.

-- Larry Huppert (Larry.Huppert@mail.com), August 18, 2000.

Get a small angle finder and place it against the wall, note the reading and then place it on the ground glass and match the angle reading of the wall surface. I have a small one I use that works well, it having a 6 foot tape measure, solar powered calculator, built in level and the angle finder. If find I use it a lot in the field as it is small & lightweight. I also use it to make sure surfaces are parallel when photographing artwork on walls.

-- Dan Smith (shooter@brigham.net), August 18, 2000.

I second the angle finder! Pat

-- pat krentz (patwandakrentz@aol.com), August 18, 2000.

Dean,

Are you concerned about the wall not being perfectly plumb? I guess some building are like this, and for this the angle finder will be your answer. An alternative is to see where the bubble lands on your level, and just transfer that approximation to your front and rear standards. Unless non-plumb walls are part of the design, the amount that a typical wall is off is probably no more than 1 degree. Unless you get a fairly expensive digital level, the typical hardware store angle finder might only resolve to 1 degree increments or larger.

-- Larry Huppert (Larry.Huppert@mail.com), August 18, 2000.

My answer would be the same which I use for copying artwork, vertically or horizontally, either way. Just place a mirror flat in the middle of your subjet, and when you see the image of the camera lens in the dead center of your cocusing screen, you are there. I mean, perfectly aligned... Hasselblad used to make a set of a round mirror for the subject and a circular one for the filter mount. With these two you can aim the camera with best possible accuracy because the O-shaped mirror causes interference patterns if you are just a tiny bi

-- Timo Ripatti (timo.ripatti@helsinkimedia.fi), August 21, 2000.

Hi: Thanks for your answers. I've been electronicaly chalenged for a few days. I'm not worried about plumb -- but now I have that tool too (thanks)-- rather beign skew to the wall horisontaly. I'll give the mirror a go and since I don't have a grid, I think I'll get a Staedler grid type tool to put on the GG and compair to the horizontals. Thanks. Dean

-- Dean Lastoria (dvlastor@sfu.ca), August 23, 2000.