Trying to understand Cambo and Phase XT compatibility

[Chris Saunders 74]

Hi everyone,
Apologies if this has already been asked. I did a search but couldn’t find a clear answer. That’s not to say that there isn’t an answer, perhaps I just didn’t understand the terminology!

I have a Phase One XT and IQ4150 and looking at adding a longer lens to my system. I have the 32HR and a 70SK but wanting to add a used 150+. But it seems the old Cambo WRS and WDS mounted lenses whilst will mount on the front of the XT won’t work without a back spacer which doesn’t look available for the XT.

Can anyone help me understand the options? I know some WDS long mm lenses have back spacers but I don’t understand if they all have the same back spacer. I also know Cambo sell a front spacer but I’m not sure if this is the right dimension for all or only 1 or 2 lenses.

I should clarify I’m not worried about X shutter and happy to use electronic shutter on the back.

If anyone can help an idiot understand it would need most appreciated.

 

[TimoK]

Is a 42mm spacer enough? I don't know anything but look at this thread: https://www.getdpi.com/forum/index.php?threads/phase-one-xt-150mm-ho-s-sb-lens.75769/

 

[4x5Australian]

Hi Chris,

Each lens type has its own flange focal distance (FFD) or length, which is listed in the manufacturer's technical brochure (PDF). The FFD is specified for infinity focus and shutter type.

For example, the RDK HR 32 FFD at infinity on a Copal 0 shutter is 69.2mm.

To achieve infinity focus on the XT or WRS camera, the FFD of the lens must be matched by the total depth of the camera, from the lens flange through to the sensor surface.

Lenses with a short FFD such as the HR 32 can be matched by the depth of the WDS lens mount plus the camera body alone. The depth of the WDS lens mount is customised for each lens FFD so that infinity focus is achieved at the infinity mark on the helical focuser.

Lenses with a long FFD such as a 150mm need additional depth and normally, such as on the WRS body, that additional depth is provided by adding a rear spacer or two, plus, depending on the situation, some front extension to the mount. Cambo makes rear spacers of 10mm, 17mm and 48mm depth.

However, the XT cannot accept the WRS rear spacers, so Cambo introduced a 48mm front spacer specifically for the XT.

In addition, just days ago, Phase One announced a 42mm rear spacer for the XT with electronic communication between the XT body and IQ4 back.

With either the 42mm rear spacer or 48mm front spacer, Cambo will customise the depth of the lens mount to achieve the required match with the lens FFD.

Hope that explains it sufficiently.

Rod

 

[Paul Spinnler]

Essentially if you are within the XT eccosystem you can only use XT lenses on the long side. Basically the new 150.

On the short side, ie without need of extenders, you can adapt any Cambo lens as the mounts are the same.

You can use XT lenses on Cambo cameras but the camera needs to modified to protect the XT connectors – there was a post by CI on this – and you'll need to use a cable and will lose shift metadata, which defeats a bit the purpose of buying XT lenses in the first place.

It might be most efficient to get a cheap Cambo body for the long side if you don't want to pay five figures for a long lens on XT specifically; you'll have more options as atm there's only the newly announced 150 XT lens which will run you a pretty penny, whereas on the Cambo side you can buy a used 180 Digaron S for 3-4k or mod analogue lenses to be mounted on Cambo – e.g. a Rodenstock 120 Macro.

 

[diggles]

Essentially if you are within the XT eccosystem you can only use XT lenses on the long side. Basically the new 150.

Can a lens like the APO Digitar 150n lens be attached to the XT with the 48mm front spacer? It might be front-heavy and could cause vignetting, but would it still function?

 

[drunkenspyder]

Essentially if you are within the XT eccosystem you can only use XT lenses on the long side. Basically the new 150.

On the short side, ie without need of extenders, you can adapt any Cambo lens as the mounts are the same.

You can use XT lenses on Cambo cameras but the camera needs to modified to protect the XT connectors – there was a post by CI on this – and you'll need to use a cable and will lose shift metadata, which defeats a bit the purpose of buying XT lenses in the first place.

It might be most efficient to get a cheap Cambo body for the long side if you don't want to pay five figures for a long lens on XT specifically; you'll have more options as atm there's only the newly announced 150 XT lens which will run you a pretty penny, whereas on the Cambo side you can buy a used 180 Digaron S for 3-4k or mod analogue lenses to be mounted on Cambo – e.g. a Rodenstock 120 Macro.

Not entirely. It just depends on the lens. I have successfully used several Mamiya and Hasselblad lenses on my XT, up to and including the old Mamiya 500 reflex and regular lenses. Some definitely better than others, and few up to the IQ4's resolution. Yep, no metadata whichever way you go here.

I concur in the recommendation about using a Combo frame as a second device. Kinda wish I hadn't sold my 1600, or my 400, or ...... I looked for he C1 post you mentioned [presumably Steve Hendrix?] regarding protecting the lens mount terminals when using the XT lenses on Cambo cameras but I could not find it. Will check with my dealer before moving down that path.

 

[Paul Spinnler]

Well I hadn't talked about adapting third party lenses with Cambo compatible adapters – that's of course possible as the XT is basically a Cambo body with just one compatible electronic rear extender in production.

I guess we'll see the 90 HR SB Tilt next.

The point is that as soon as you need rear extension you can only use lenses which let you, with the helical in place, reach infinity with THAT specific 42mm XT extender.

Based on Warren's comment I looked up the front extender and indeed Cambo seems to make this, so if the total FFD is within the distance necessary to reach infinity other longer lenses than the new 150 should also be possible to use, although with the risk of stronger vignetting while shifting, I'd assume.

I guess one would need to try. Cambo cameras are not thaaat expensive, so having a second body is not such a problem - especially the 180 Digaron seems worthwhile to consider. There was a great deal a few months back on one, it in the end sold via eBay for a very good price, I remember.

 

[4x5Australian]

Here is the Cambo 48mm front spacer on the Cambo website: https://www.cambo.com/en/wide-rs-series/wrs-digital-lenspanels/wtsa-180l-tilt-swing/wrs-1049/

The text says [with my edits for clarification]:

The WRS-1049 [48mm] Front-Adapter can replace the WRS-1048 [48mm rear spacer] in combination with Cambo WRS Short Barrel Lens Panels.

This way you can use a Cambo WRS Short Barrel [lens] on the Phase One XT body, as the XT body doesn't accept rear spacers.

Rod

 

[Chris Saunders 74]

Wow. Thank you all for the comprehensive and clear replies. I think I now understand! Not everything but enough to know what direction to go. I think the answer is going to be for me a second Cambo unit for these applications. Thanks again all!!

 

[Steve Hendrix]

Yes, just use the front spacer on the XT. For XT lenses on Cambo, just make sure your body has the space opened up in the front to accommodate the contct pins of the XT lenses. And I have (3) Rodenstock 180mm lenses on my desk from our certified pre-owned (CI inspected) inventory in Cambo mount, one in X Shutter, one in Copal, and one (not yet listed in our store) in Aperture Mount)

https://digitalback.com/collections...ort-barrel-spacer-copal-0-certified-pre-owned

https://digitalback.com/collections...long-helical-short-barrel-lens-spacer-wrx-180


Steve Hendrix/CI