I'm confused about lens boards?

[stradibarrius]

It sounds crazy that I could be confused about a flat plate with a hole in the center but I am.
When buying lens boards to fit a given lens what determines the size of the hole?
I only have one lens and one lens board so I have never taken it apart.
Does the shutter go through the hole or does the lens go through the hole?
At KEH they have their lens boards divided by camera and then by hole size.

second question, I bought a second lens board from KEH for a Calumet cc-400. When I got the board I compared it to the lens board I have and noticed that the light ridge around the board is farther in from the edge on the new one so it will not fit on the camera. KEH does not make a distinction between the lens boards so how do know what to order?

[Jim Jones]

It is the shutter, not the lens, that is retained by the lens board. Older shutters were often mounted in a flange that was screwed to the face of the board. Newer shutters are usually retained by a ring screwed onto the rear of the shutter. The hole in the board may vary for one size of shutter, depending on the design of the ring. Some rings, and a flange used as a ring, should have a hole that just fits the threads on the rear of the shutter. Other rings have a lip that is intended to fit into a slightly larger hole.

As for the style of lens boards of a given size, that varies widely. My Calumet accepts a 4" square 1/4" thick board with a rabbet 1/4" wide leaving the board 1/8 thick around the rear edges. This was a very frequently used size decades ago. Many of us routinely make such boards from 1/4" plywood or MDF, or build them up from 1/8 material. Sometimes the edges of the hole have to be rabbeted to accomodate the length of the shutter threads. When building a board up from 1/8" plywood or MDF, the smaller rear square is merely a light trap and need not contribute to structural strength. Therefore, it can be cut from black foam core or built up with mounting board.

[stradibarrius]

The board that fits my cc-400 has the ridge that is about 2mm tall and about 2-3 mm from the edge of the board. The one I just received, the ridge is the same height but is 3/16 from the edge of the board so it will not fit in the groove in the front standard.

Both are 4"x4" and 1/8" thick and gray in color.

is there a model distinction between the two types of lens board?

[sanchi heuser]

It sounds crazy that I could be confused about a flat plate with a hole in the center but I am.
When buying lens boards to fit a given lens what determines the size of the hole?
I only have one lens and one lens board so I have never taken it apart.
Does the shutter go through the hole or does the lens go through the hole?
At KEH they have their lens boards divided by camera and then by hole size.
...
...

Hi,
may have a look at that video:
http://www.youtube.com/watch?v=2JjzwjO5ZSE

The hole diameter is for
Copal No. 0 = 34,7 mm
Copal No. 1 = 41,8 mm
Copal No. 3 = 65,0 mm

(from the website of S.K.Grimes)

Good Luck

[Jim Jones]

Strad -- If the board from KEH fits securely, it should work. I just now looked at my ancient Calumet. It accepts both boards like your original one and like I described in post 2. The ridge (or the rabbeted corner in older boards) serves as a light trap. It might not even be necessary in studio work. The KEH board uses the ridge as a light trap inside the smaller opening of the lens board mount, not in the groove.

[stradibarrius]

Thanks Jim, the problem is the ridge on the board will not fit into the groove on the front standard so it will not even go into place. There is no fix for this particular board I was just trying to find out how to distinguish between the two types of Calumet lens boards.

[John Koehrer]

Since the boards aren't branded(usually) it's just a guess on their part.
OK, it's 4X4 and gray=your brand. I doubt that they have anyone pulling orders that has actually used different cameras
or that can identify different boards visually.
Obviously today's solution is return it and try again. I don't know if it would help to actually talk to someone there or not

[Floyd Waller]

What you may have in the board that has the raised portion 3/16 from the edge is a Graphic View board. Both the early Calumet and the Graphic View used 4 X 4 boards. I have seen them confused many times and commonly they are both gray. The Calumet boards have a narrow about 1/16th raised bead about 1/8" from the edge around the back. The Graphic View has a higher thicker squarish bead about 3/16" from the edge and the real clue is the lower edge of the board is slanted or beveled whereas the Calumet is uniform all way around providing it has not been modified. Frequently, depending on the age of the Graphic View board, the front gray surface will have a somewhat mottled or dappled appearance and some of those are even a bit textured. A few of the earliest were smooth almost aluminum gray. The Calumet boards tended to be just a uniform light gray paint and the very last ones along with their later cameras were all black. I have owned and used both systems.

[stradibarrius]

Floyd, you are exactly right in your description of the two boards. I don't have the knowledge about the graphic view vs. the Calumet but your description is dead on.
I will say that my Calumet board has the bevel at the bottom too.

[Dan Fromm]

Jim, Barry, as I've said in another thread that was locked because one poster generated a lot of abuse (gave, and others returned it), KEH doesn't know sh!t about lens boards. I've bought 4 boards from them of which three were wrong.

Barry, send your board what doesn't fit y'r CC-400 back to KEH now and tell them to learn their business. Do it now.