Issues mounting Nikkor-w 300/5.6 in Toyo field lensboard

[grey]

Trying to mount a Nikkor-w 300/5.6 in a Toyo field lensboard, and I'm running into two issues.

Issue 1 - What are the 4 small holes drilled into the lensboard and how do I plug them?


Issue 2 - I cannot get the lock ring to actually do its job. I'm a LF newb, so I may be doing something wrong here ... I separated the front and rear elements and put the front element down. I then put the lensboard over the front element and tried to tighten the lock ring. It tightens, but due to its shape (like a top hat), the lens is not actually secured to the lensboard.


Any help would be greatly appreciated!

[Doremus Scudder]

grey,

First, your lensboard is drilled to be used with a flange. The flange has threads in it and is mounted to the lensboard with screws (hence the holes and Issue #1). To mount a lens to a flange, you simply remove the rear element and screw it into the threads inside the flange.

It looks to me as if the hole for the flange is actually to big. That's what is keeping your locking ring from hitting anything You may be able to reverse the lock ring with the collar toward the lensboard and get purchase that way. If not, you may need to buy a new lensboard with a proper-size hole or, alternatively, you could get the correct flange.

Best,

[grey]

grey,

First, your lensboard is drilled to be used with a flange. The flange has threads in it and is mounted to the lensboard with screws (hence the holes and Issue #1). To mount a lens to a flange, you simply remove the rear element and screw it into the threads inside the flange.

It looks to me as if the hole for the flange is actually to big. That's what is keeping your locking ring from hitting anything You may be able to reverse the lock ring with the collar toward the lensboard and get purchase that way. If not, you may need to buy a new lensboard with a proper-size hole or, alternatively, you could get the correct flange.

Best,

Thanks!

[Sal Santamaura]

...What are the 4 small holes drilled into the lensboard and how do I plug them?...

Have them "plugged" with four screws that will hold the appropriate flange. Here's an S.K. Grimes page

http://www.skgrimes.com/products/mou...-stock-flanges

which offers said flanges. I'd also suggest you send the board to Adam at Grimes and have him mount the flange for you.

By the way, congratulations on obtaining that lens. It's the sharpest 300mm I've found, especially at small apertures.

[ic-racer]

Just get a new board. Keep that one for some other project.

[grey]

Thank you all for the information! Never even heard of mounting flanges, etc. :/

[grey]

The more I'm researching, the more I'm finding ...

I found this thread: http://www.largeformatphotography.in...ems-over-sized that indicates a proper Copal #3 lock ring should have a spacer with it, which obviously didn't come with this second-hand lens. That spacer makes perfect sense! Just ordered one off ebay, but until then, I'll reverse the ring and make it work!

Thanks again all for the info!

[David Lobato]

The Toyo Field cameras I'm familiar with have a max bellows extension of 305mm. Are you aware of that? There was a Toyo 4 inch extension for the back but they are hard to find.

[tgtaylor]

The Toyo AX has a maximum extension of 321mm without using the extension back and a 300mm F9 Nikkor-M works fine with a flat lensboard. Unless the spacer and screws solves the problems, I'd get a new board and have it drilled-out for a copal 3 lens. Toyo only made 0 and 1 LB's for the field.

Actually that lens is on the heavy side for a field camera. The 300M would be a better choice but since you have it...

Thomas

[grey]

The Toyo Field cameras I'm familiar with have a max bellows extension of 305mm. Are you aware of that? There was a Toyo 4 inch extension for the back but they are hard to find.

Yes! I tried it out yesterday, and it works like a charm! I was concerned about the lack of bellows draw and have a search running on ebay for the 4" extended back, but it doesn't look like it's going to be necessary.