Mamiya RB to large format adapter

[xkaes]

Anyone ever hear of an adapter/board that allows you to use Mamiya 6x7 RB lenses on a large format camera -- perhaps 6x7/6x9/4x5 camera??????

 

[Dave Parker]

Nope, I have never heard of one, you should be able to cover 6x7 and 6x9 with and RB lens, but I think you would not be able to cover 4x5 with an RB lens...I imagine if you got a hold of a junk RB you could remove the mount and make your own board with it.

Dave

 

[Troy Ammons]

The image circles are pretty big and advertised on on the mamiya site.

I would agree with above and buy a body and cut it up for what you need.

You need some way to mount cock and fire the lens and thats about it.

http://www.mamiya.com/cameras.asp?id=1&id2=15

 

[Nick Zentena]

No but Shen Hao used [still does?] to make an adapter to mount Mamiya backs on thier 4x5s. Isn't the Mamiya back just a Graflex type?

 

[ricksplace]

Yes, the mamiya RB67 back fits on the graflex 2-1/4 X 3-1/4 graflock back. I asked the question on this board a few months ago and was told it fits, so I bought an RB67 back for my Century Graphic. It fits perfectly and works great. It is much better built than the graflex lever-wind back.

 

[Dave Wooten]

I think the auto wind back for RB is actually 6 x 8 (?) I think,

 

[waynecrider]

There's all kinds of strange adapters floating around Ebay. I believe the last one I saw of interest was an adapter to mount a Hassy on either my Nikon or Canon. I'm going to have to look for that one again.

It would take some way to stop the lens down in order for a lens to work, or in the case of an RB, you would have top manually hold the lens closed. Any machinist worth their salt could fabricate a board with a holding mount out of aluminum. It probably would cost you more then you'd want to pay tho to get an image that wouldn't cover anything better then 6x7. Any excess coverage by the lens would be to insure peak 6x7 frame performance.

 

[Marco Gilardetti]

Any excess coverage by the lens would be to insure peak 6x7 frame performance.

Though, this may be worth experimenting. Lenses like the 127mm cover up to 6x7'' (inches, not centimeters!!!), the 180mm even 8x10''! If used at 4x5'' the results could perhaps be good if not awesome.

You will have a hard time firing and cocking the shutter, though! The pins which control shutter's operation would be INSIDE the camera's body.

 

[Nick Zentena]

Marco do you mean it lights an 6"x7" image circle or that it actually covers?

 

[Marco Gilardetti]

It is given among specifications as "covered area", so I assume it's not a circle.

 

[waynecrider]

Though, this may be worth experimenting. Lenses like the 127mm cover up to 6x7'' (inches, not centimeters!!!), the 180mm even 8x10''! If used at 4x5'' the results could perhaps be good if not awesome.

You will have a hard time firing and cocking the shutter, though! The pins which control shutter's operation would be INSIDE the camera's body.

Please divulge your resource. Btw, I have a 135mm Optar that will barely give me much movements, at least untill I rack the bellows out, but then I'm not at infinity.

 

[Troy Ammons]

I think the auto wind back for RB is actually 6 x 8 (?) I think,

It works both ways since the RB is basically a graflok back. I have a Horseman 6x9 back on my rb. I only get a 76mm wide image though. I also used that same back on a baby graphic. Also used a 645 RB back on a baby graphic.

Sometimes it takes some clearancing to make them work.

 

[Marco Gilardetti]

Please divulge your resource. Btw, I have a 135mm Optar that will barely give me much movements, at least untill I rack the bellows out, but then I'm not at infinity.

The source is the link posted above by Troy Ammons.

I'll paste here the data sheet of the 127mm for your convenience:

127mm f/3.5 Specifications
Optical Construction 6 elements/4 groups
Angle of View 39°
Diaphragm Automatic
Minimum Aperture 32
Shutter Seiko #1 mechanical lens shutter, 1~1/400 sec., T (time), X contact (flash synchronization at all speeds)
Equivalent Focal Length for 35mm 62mm
Minimum Focusing Distance 2' 1.2" / 639mm
Magnification 0.36x
Area Covered 6.1 x 7.6" / 155 x 192mm
Filter Size 77mm
Lens Hood Screw-in
Dimensions (L x W) 2.9 x 3.8" / 74 x 97.2mm
Weight 1 lb. 12 oz. / 780 g.

 

[Troy Ammons]

Even though Mamiya list the lens coverage as fairly large I doubt any lenses beyond a 150mm lens would work for LF due to vignetting at the rear of the lens mount. I ran into the same problem with using mamiya press lenses for 4x5. The numbers must be for the optics only. I looked at photos of the 180, 250, 350 and 500 and none of them look like they would work without vignetting.

Actually the 150 rear element is a little recessed, so it is possible it could vignette also.

The 90mm looks like it barely covers 4x5, so no movements and the 127mm lens probably would work also, but I dont have a 127mm lens laying around to look at.

I think also another downer is the weight. My RB 90mm lens weighs almost 2#.

3 rb lenses would weigh more than my super graphic with a 150mm G-Claron lens.

It an interesting idea though.

 

[smcclarin]

B&H has one: Dead Link Removed
this could be used to rig a Toyo or other lensboard. you may not like the price, and the other option requires some frankenstine tom foolery with a user body to behead the front standard, but it has been done in previous posts with a Toyo View camera.

Best of Luck!

 

[keithwms]

You can quite easily adapt rb/rz lenses to LF. Look up Erie Patsellis on APUG, he has a nice solution which allows you to trigger the leaf shutter. My method is a bit simpler, I just hand shutter; all I do is fasten the lens onto a makeshift 1/8" thick lensboard with a big hole in it... I use a rear lens cap to attach the lens to the board. Works like a charm.

Coverage... there is quite a lot at close focus. I have done some 5x7 macro with some tilt using an rz 110/2.8 lens. Even at infinity focus, you can fill most of a sheet of 4x5 film with these lenses. But for portrait / closeup etc. you can easily fill 4x5. (Note: Per Volquartz sometimes uses a 35mm lens for LF macro...)

The main thing is that the rb/rz lenses are quite heavy and will put a good deal of strain on a camera. I have an all-metal 5x7 rittreck that stands up well, it's very robust. A cambo would probably do well. But a wooden field camera... don't try to put an rb/rz lens on that. You'll probably break something.

 

[Marc B.]

xkaes,
Yes I have seen a lens board adapter for LF, and from different vendors. Don't remember who had it; ie,
an eBay seller from China, Calumet, etc...? It was advertised as being for RB [and] RZ lenses.
As stated by others, unsure how you were supposed to cock and fire the shutter, and without electrical control for the RZ lenses,
how you would obtain different speeds, other than the [dead battery] default speed of 1/400th.
I think this adapter was intended more for RB lenses, and those using a digital back on their LF cameras.
Price was high, in the $450-$550/USD range.

 

[Maris]

The Mamiya 127mm f3.8 lens covers 4x5.

I just tried it on my Tachihara 45GF. Coverage is tight with no movements practicable. Incidentally the 155mm X 192mm "area covered" specification for the 127mm lens refers to the amount of subject the lens sees at its closest focussing position. The bellows focussing on the Mamiya RB67 makes all lenses "macro" lenses; a very nice feature.

 

[hpulley]

Yes that's right, it is not an illuminated area but a 'macro' area. The numbers would be outrageous if they were really for illumination, they'd cover more area than many large format lenses.

 

[Athiril]

Hmm I have the 180mm.... Im going to see how how much it covers.. brb.

Edit:

The 180mm Sekor C f/4.5

It covers more than 4x5".. not sure by how much.

But I set the lens to infinite focus with the bellows., an object 2 meters away (but infinite focus on the lens/bellows for that lens) is fully covered over the ground glass.

Edit 2:

Still covering it with 2.8cm of rise (max on speed graphic.. got a CC400.. but might be a PITA to set up at night.. will try on tripod in day time) = 6.2 inches so far, but not sure how evenly since its not light tight.. just holding it there.

But it bodes very well for closer focus distances such as for portrait!

 

[keithwms]

Yes, again, at close focus these lenses are quite amazing. Even the (really fast!) rz 110/2.8 has decent coverage of 4x5 at portrait distances. But I find it a real gift for higher mag macro because it is so fast... even at large mag, you can at least still see something on your ground glass without having to adjust your eyes for 10 mins under a cloth. I mean, most LF lenses that, wide open, only give you f/5.6 or so, and so when you're at 3:1 or whatever, focusing takes a lot of patience and a lot of light.

Incidentally, rb users: the 100/2.8 can be used on the rb if you are willing to hand shutter. It's a very simple operation, you just pull a couple of pins. This operation does not preclude you from using the lens on an rz body.

 

[Athiril]

The 100/2.8? Or 110mm?

I've been dying for f/2.8 MF....

I mounted a Mamiya Sekor 55mm f/1.8 M42.. it's looking pretty good with a 2x TC on it for close non-macro focus.

 

[Simon Benton]

The 150mm RB soft focus lens covers 4X5 - these are great soft focus lenses once the learning curve is over and are currently on Ebay, brand new, at amazing prices from a Japan camera store. I bought 2 and they are in orginal unopened box - great buy for less than $140. Using a front from an old Pro S it is relatively easy to make a mount that allows the shutter to be fired and cocked. I believe there is an article on the Large Format forum explaing how to do this.

 

[epatsellis]

Yes Simon, at one point (or several) I've responded to these threads with a link to my website. With the success of getting my domain name back, I will be reposting some of these articles again. It's really not that hard to make a functional adapter to use them, including the shutters.

erie

 

[k_jupiter]

Acouple of things... Someone posted a long time ago how to take the front piece off a trashed rb body and mount it on a lens board to use with rb lens. The trick is toget the cocking of the shutter correct. I have the front piece, just never got aroundtoit so it's just another project.

I have no idea of coverage. Some claims seem a bit outrageous.

The rb backs will fit a Grafex back. I have used it on my 2x3 Speed. But ya know... I think the film plane offset is just not quite correct. The negatives are a bit..soft.

YMMV.

tim in san jose