Using RB67 lenses on 4x5?

[kurtdriver]

I'm hoping to use my existing lenses on my new (to me) Super Cambo. Two questions arise, how do I mount them, is a new lensboard required? If so I should probably just buy a 4x5 lens. I'm a student again, and could definitely save a couple bucks, which is why I want to use the lenses I already have. Would these lenses have proper coverage for the larger format? Someone has done this, I'm certain. Thanks, Kurt

[Daniel_Buck]

I doubt they would cover?

[erie patsellis]

90 and up cover, somewhat. Depends on your definition of cover, do you want a gazillion line pairs/mm all the way to the house next door? Or will a slight softening at the very edges be acceptable?

[Turner Reich]

They wouldn't cover completely but somewhere on the web someone put the front end of an RB on a view camera, it gave focusing. Kinda weird but it worked, I think they got 6x8 or 9 out of it.

[erie patsellis]

still using 6x7 backs, and using the rotating adapter as well, or you can use the 4x5 back. I assume you're referring to my Toyo/RB hybrid:

http://i144.photobucket.com/albums/r181/epatsellis/DSCF7015.jpg

[rdenney]

They wouldn't cover completely but somewhere on the web someone put the front end of an RB on a view camera, it gave focusing. Kinda weird but it worked, I think they got 6x8 or 9 out of it.

Yeah, couple it with a 6x7 holder and you have a camera that has limited movements.

Ultimately, though, I think it will a frustrating exercise. Large-format lenses of exceptional quality are so cheap now that it's not really worth a bit effort to cobble something else together. One might more easily fabricate the bits needed to provide a shift capability on the front of a real RB67.

Rick "who paid less for a 47/5.6 Super Angulon than for a 45mm SMC Pentax 67" Denney

[kurtdriver]

Thank you guys, I guess I'll just wait until I have a lens or two made for LF. In the meantime the RB67 shoots nice pictures as is.

[Rodney Polden]

Well, it's the only way that I've found to enjoy a 37mm fisheye on 4x5. Some great new perspectives on the world, believe me...

[venchka]

...

Rick "who paid less for a 47/5.6 Super Angulon than for a 45mm SMC Pentax 67" Denney



Wayne, wondering how the heck you managed that, on the Upper East Side of Texas.

[rdenney]

Wayne, wondering how the heck you managed that, on the Upper East Side of Texas.

The 47 is not an XL, and dates from the early days of the 5.6 version--maybe the early 70's. It's in a Compur 00, which dates it. I paid $300 for it about five years ago. The Pentax lens is newer, but I bought it at KEH within the last year, and in Bargain condition (that anyone else would have called EX+) cost me $275. Of course, it doesn't have a shutter.

Rick "not a fan of that 00 shutter, but still liking the lens for 6x9" Denney

[speedtrials]

Hey Rodney,
I've been thinking of giving this a shot. I have a 35mm fisheye for Bronica SQ that I want to use. Can you post some of your results with this type of setup?

Cheers,
Nick



Well, it's the only way that I've found to enjoy a 37mm fisheye on 4x5. Some great new perspectives on the world, believe me...

[SocalAstro]

Rodney,

I've been thinking of doing the same thing actually. I too would love to see a picture taken with this lens to see how much actual coverage one gets on a 4x5.

-Leon



Well, it's the only way that I've found to enjoy a 37mm fisheye on 4x5. Some great new perspectives on the world, believe me...

[vinny]

cut a hole in the back of a rear rb lens cap, glue that to a copal #3 lens board, mount lens on camera, shoot.

[rdenney]

Rodney,

I've been thinking of doing the same thing actually. I too would love to see a picture taken with this lens to see how much actual coverage one gets on a 4x5.

-Leon

A fisheye produces a round image with a diameter roughly three times the focal length of the lens. For most fisheye lenses, the coverage is 180 degrees edge to edge of that round image. If the focal length is one-third the film diagonal, then we call it a full-frame fisheye. If the focal length is one-third the narrow dimension, we call it a circular fisheye. But the lenses are the same and differ only in focal length.

So, a 35mm fisheye would produce a round image approximately 105mm in diameter and would be a full-frame fisheye on the ~6x7 format and a circular fisheye (almost) on 4x5. I have a 30mm fisheye which is a full-frame fisheye for 6x6, and a 16 which is full-frame for 24x36. On 4x5, they would make round images roughly 90 and 48mm in diameter. Might be less than meets the eye.

Rick "a 55mm fisheye for 4x5--now your talkin'!" Denney

[Rodney Polden]

The RB-lenses-on-4x5 is an ongoing project for me at present, and thanks go to Erie Patsellis for getting this far - his description of the modifications for mounting the lenses were what got me started. (Thanks again, Erie!)

The 37mm Mamiya gives an image circle around 90 mm, so it certainly doesn't cover 4x5, but with that lens, I was actually aiming to end up with circular images on a black b/g. Most of the long lenses in the RB range seem to cover 4x5, though I cannot speak to sharpness in the corners as yet. Longer lenses are less interesting for me though, since I have LF lenses that already do the job better. For others, that might be worth pursuing.

What I hadn't allowed for with the fisheye, was the "petal" style fixed lens-hood coming so obtrusively into the image. As yet, I haven't reconciled myself to the idea of grinding those lens-hood elements off the front of the lens. Maybe I will, because the perspective certainly is intriguing, but I guess it will inevitably "change" (to put it mildly) the resale value of a lens I paid $1400 for, as well as removing the option of um, well, having a lenshood. When I'm shooting on the RB, the lens-hood is really quite a bonus, and keeps a lot of otherwise inevitable sun-flare out of the image.

My plan was to use the lens on a MPP Mk 8, but so far I have only achieved infinity focus on my Horseman monorail with bag bellows, mostly due to the additional extension that comes from the modified RB lensboard thickness. Hand-held on the Horseman monorail? Probably not. Still working on getting the movements (tilt mostly) that I was also looking for.... There's not easily enough space to accommodate a recessed stage to take the RB lensboard-mod, at least not on 4x5.

Is there a word in the English language that means "toooomanyprojectsonthego"?

[ruckusman]

I'd love to know any details you could share on the Toyo RB67. I used to have a Mamiya camera front mount attached Linhof Technika board, but my shutter cocking mechanism wasn't at all good.