Size of Sinar lensboard?

I'm interested in buying a lens on Ebay. The lens is mounted on a Sinar

lensboard but I want to use it on a different camera, which has a 1 3/8"

diameter hole for the lens.

 

Question: How do Sinar lenses mount on their lensboards?

 

If the lenses just fit into a hole and have a screw retaining ring on the

back, what size hole do they need?

 

Supplementary question: What size are Sinar lensboards?

 

I shouldn't need to ask these questions because I used to have a S2 - but I've

forgotten!

<i>If the lenses just fit into a hole and have a screw retaining ring on the back, what size hole do they need? </i><p>

That is the pertinent question and the answer is: Depends on the lens!<p>

And what size lensboard you need depends upon the camera you want to use.<p>

Provide details of each and you will get answers.

Hi Pico,

 

Thanks for your response. What I really need to know is how are Sinar lenses fitted to their lensboard? and if they just fit into a hole with a backing screw ring, what size is it?

 

The camera I want to fit it to is an old New Vue and I want to fit a 180mm schneider to it. I have the lensboard for the New Vue, which is 4" x 4"

All depends on the shutter. Modern Copal, etc shutters come in standard sizes with retaining rings to secure them in place. The old shutters, Kodak, Ilex, etc had flanges the shutter screwed into, they were secured to the board by screws, the lens board hole sizes varied greatly. To fit a shutter to a board it's best to start with the shutter and find a corresponding board or at least one that can be drilled to size.

At the moment on the bench I have a 180mm Schneider Symmar-S F:5.6/180mm ("Multicoating") in a Copal #1 shutter and it requires a 39mm hole in the board. 40mm is a better fit. A jam nut (screw retaining ring) holds it on from the back side. (You unscrew the rear element to mount it with the nut then screw the rear element back on.)

 

Sorry, that's all I have at my fingertips.

 

Please measure your Sinar lensboard. 4x4" seems small.

 

Hope this helps.

Hey, sorry for not answering your question. The opening in your board is 35mm. You might be able to file it open enough to fit the lens you are getting.

 

(Keeping it simple)

Re "If the lenses just fit into a hole and have a screw retaining ring on the back, what size

hole do they need?". As Pico says, it depends on the lens. More specifically, it depends on

the shutter that the lens is mounted in. Typically a 180 mm lens will be mounted in a #1

shutter, which generally needs a 41.6 mm diameter hole in a lensboad -- see http://www.skgrimes.com/products/index.htm for a table for the standard modern size

shuttters. (The table is for Copal shutters, but recent Compur shutters will most likely be

the same.)

 

As Pico says, usually one uses a retaining ring on the other side. Some shutters have a

projecting screw to prevent rotation, but frequently people remove these.

 

If the lens seems to be a low, bargin price, be sure to check that it has a shutter. Some

lenses for Sinar cameras are in "DB" mounts, which means that they don't have their own

shutter, but instead use a behind-the-lens shutter, which can be shared with several

lenses. Basically, these are barrel-mount, shutterless lens, and should be priced

accordingly.

 

So what you really need to check in the auction is what shutter the lens is mounted in.

 

The 35 mm hole of your present lensboard is suitable for size 0 shutters. So you could

look for a 150 mm or shorter lens (which are typically in size 0 shutters), or have this

lensboard bored out to a larger hole size, or look for another lensboard.

Pico and Michael,

 

Many thanks - that's exactly the info I need.

Sinar had their own shutter system, called a "DB" shutter. This consisted of a large behind-lens shutter, and took lenses mounted on a DB board, with iris only.

 

If the lens is a Sinar DB mounting then you should be aware that it has no shutter of its own, and will need to be fitted to a Copal or SH Compur shutter. This is a fairly expensive option, and lenses mounted in DB boards should be avoided unless they're very cheap, or if you're lucky enough to own a Sinar DB system.

 

Standard Sinar lensboards OTOH, are no different from any other lensboard. They're just a square plate with a hole in the middle.

 

Almost any LF shutter made after WWII will be in the standard series of "00", "0", 1, 2 or 3, which are standardised sizes with the same mounting diameter for each size, regardless of make. You should have no trouble swapping lenses from one make of lensboard to another, provided that the hole is for the same size of shutter.

 

1 3/8 inch is approximately 35mm, which would make it suitable for a number 0 shutter.

 

See this link to S.K.Grimes website for a comparison of hole size to shutter number.

 

http://www.skgrimes.com/lensmount/shutmt/index.htm

OOops! Sorry for almost duplicating Michael's post. I should've waited for the page to finish loading before I posted a response shouldn't I?

<i>Standard Sinar lensboards OTOH, are no different from any other lensboard. They're just a square plate with a hole in the middle. </i><p>

Well, they really aren't. While you can, in a pinch, use a flat board on a Sinar, the correct ones have a lip on the backside a few millimeters from the edge. The lip seats the lensboard into a detent on the camera to obviate light leaks. If you use a flat board it might not fit tight and the board lock on top and may not seat at all, each depending upon how thick the board is.

<p>

Some lensboards do not put the hole in the center, for example the Linhof Color and the Linhof Technika.

<p>

(And of course there are round lensboards as well as regular trapezoids, but I digress.) :)