The GetDPI Photography Forum

Great to see you here. Join our insightful photographic forum today and start tapping into a huge wealth of photographic knowledge. Completing our simple registration process will allow you to gain access to exclusive content, add your own topics and posts, share your work and connect with other members through your own private inbox! And don’t forget to say hi!

Want to marry Sinar P and Arca 6x9, have questions

med

Active member
With the extremely low (relative) cost, I am thinking of picking up a Sinar P or P2 to use for macro and studio work, but I would like to be clear on a few things before I take the plunge. My goal is to use it for both 4x5 work, as well as with digital backs (only with telephoto and macro lenses... for wide use I have a tech cam). With Live View being as good as it is on modern CMOS backs, I'm not concerned with getting a sliding back or anything. I simply want to mount a DB on a 4x5 Sinar P and use some of my longer 4x5 lenses with it (I realize the results may not be amazing... but I want to try it! I do have some of the sharper 4x5 lenses available, such as the 135 Sironar-S and APO Ronar 300).

One of the options I was thinking of, was to manufacture or acquire an adaptor that could "receive" my existing Arca 6x9 plates for roll film and digital backs, and mount into the rear standard in place of the 4x5 Graflock back. I can't find an existing adaptor for this, but I have seen Arca 110mm lens board to Sinar lens board adaptors (or SK Grimes could make one fairly easily). What isn't clear based on images/literature I've been able to find is:

1. Is the size and style of the 4x5 graflock back identical to the Sinar lens board? I.e. could you put a standard Sinar lens board on the "back" of the camera in place of the graflock back?

2. Is the size of the Arca 6x9 plates that I have identical to the 110mm lens boards? I.e. if I had a Sinar lens board that could receive 110mm Arca boards, could I mount my DB adaptor plates to it instead of lens boards?

If this isn't possible (i.e. if the lens boards can't be mounted at the back), I have seen graflock plates to adapt to various camera mounts so I suppose it would be possible to find/make a graflock-sized plate that could receive either Arca 6x9 plates or DBs directly. Some searching led me to this one but it is quite costly. Is the graflock standard secure enough that there wouldn't be much or any play if I went that route?
 

Oren Grad

Active member
1. Is the size and style of the 4x5 graflock back identical to the Sinar lens board? I.e. could you put a standard Sinar lens board on the "back" of the camera in place of the graflock back?
No.

There are various something-to-Graflok adapter plates offered by Chinese vendors on eBay; might be worth a look to see whether one of them offers what you need.
 

med

Active member
No.

There are various something-to-Graflok adapter plates offered by Chinese vendors on eBay; might be worth a look to see whether one of them offers what you need.
Thanks. I re-read my question and just to be clear, I don't mean inserting the Sinar lens board into the Gracklock/International receiver, but directly into the format frame (if this is possible). Some images and videos I have seen with the P2 disassembled look like the front and rear format frames are identical (similar to my Arca Swiss F-Line 4x5) so if you wanted to for whatever reason, you could put the 4x5 Graflock back on the front, or the lens board on the rear.

And thanks for the tip! I was not able to find one on Ebay but SK Grimes should be able to make one without much fuss I think. Are there any downsides to using a Graflock plate in terms of tolerances or movement? I was thinking that the fewer adaptors the better, but if it is secure then it probably doesn't matter.
 

Alan

Active member
1. Is the size and style of the 4x5 graflock back identical to the Sinar lens board? I.e. could you put a standard Sinar lens board on the "back" of the camera in place of the graflock back?

2. Is the size of the Arca 6x9 plates that I have identical to the 110mm lens boards? I.e. if I had a Sinar lens board that could receive 110mm Arca boards, could I mount my DB adaptor plates to it instead of lens boards?
Yes* to both:
Lensboards, bellows and backs generally* have the same flange design and can be inserted into each side of front and rear standards with Sinar and Arca cameras. (* I think there are some exceptions - ask at the LF forum.)

A Sinar to Arca 110 adapter would allow you to put an Arca-fit back on a Sinar.
 

Oren Grad

Active member
Ah, my bad. My own Sinar kit (4x5 F2, 5x7 and 8x10 P) is currently broken down into components and piled into a big box. I just pulled out the 4x5 F2 rear standard to refresh my recollection and indeed, back, bellows and lensboards are fully interchangeable on it. I don't have a 4x5 P standard so can't confirm that directly but imagine it should be the same.

FWIW, I have used a Chinese Canon EF-to-Graflok plate to mount my EOS 6D on the F2, to grab a few test captures with some 210mm view camera lenses.

I don't think I'd be happy with either an F2 or a P as a platform for a digital back. I don't think the rigidity and overall precision are quite up to snuff. Sure, they'd be usable, but I expect I'd be routinely annoyed by the slop at various points. It was worth it to me to do the experiment with the 6D because I already had the Sinar camera, and the EF-to-Graflok plate was cheap. But I wouldn't invest the money to buy a complete film-era Sinar camera, or probably any other 4x5 monorail, with the intent of using it with a digital back. I don't know, maybe the M-line Arca is rigid/precise enough; I've never seen one in the flesh. But in general, I'd be saving toward a late-model camera intended for digital backs if I wanted to put one on a view camera. As always, YMMV.

Re Graflok adapters in particular, the quality of fit is going to vary. You can't assume that a random plate will be a tight fit just because it's Graflok. Of course, if you can send the camera back to SK Grimes you can probably have Adam fabricate a custom adapter to whatever tolerances you need.

EDIT: For your amusement, I'll attach a couple of my 6D captures from the 210mm Apo-Sironar-S. Per my notes those should be f/11 and f/22. Processed via ACR with no sharpening, resized only in factors of 2 via bicubic. Dunno what vBulletin might do in rendering it, though.



 
Last edited:

Cambo

Member
Thanks. I re-read my question and just to be clear, I don't mean inserting the Sinar lens board into the Gracklock/International receiver, but directly into the format frame (if this is possible). Some images and videos I have seen with the P2 disassembled look like the front and rear format frames are identical (similar to my Arca Swiss F-Line 4x5) so if you wanted to for whatever reason, you could put the 4x5 Graflock back on the front, or the lens board on the rear.

And thanks for the tip! I was not able to find one on Ebay but SK Grimes should be able to make one without much fuss I think. Are there any downsides to using a Graflock plate in terms of tolerances or movement? I was thinking that the fewer adaptors the better, but if it is secure then it probably doesn't matter.
For that Cambo has the DPSB-45 (direct plate for Sinar) adapter plate which can be combined with the SLW adapter needed for the specific back.
 

med

Active member
Ah, my bad. My own Sinar kit (4x5 F2, 5x7 and 8x10 P) is currently broken down into components and piled into a big box. I just pulled out the 4x5 F2 rear standard to refresh my recollection and indeed, back, bellows and lensboards are fully interchangeable on it. I don't have a 4x5 P standard so can't confirm that directly but imagine it should be the same.

FWIW, I have used a Chinese Canon EF-to-Graflok plate to mount my EOS 6D on the F2, to grab a few test captures with some 210mm view camera lenses.

I don't think I'd be happy with either an F2 or a P as a platform for a digital back. I don't think the rigidity and overall precision are quite up to snuff. Sure, they'd be usable, but I expect I'd be routinely annoyed by the slop at various points. It was worth it to me to do the experiment with the 6D because I already had the Sinar camera, and the EF-to-Graflok plate was cheap. But I wouldn't invest the money to buy a complete film-era Sinar camera, or probably any other 4x5 monorail, with the intent of using it with a digital back. I don't know, maybe the M-line Arca is rigid/precise enough; I've never seen one in the flesh. But in general, I'd be saving toward a late-model camera intended for digital backs if I wanted to put one on a view camera. As always, YMMV.

Re Graflok adapters in particular, the quality of fit is going to vary. You can't assume that a random plate will be a tight fit just because it's Graflok. Of course, if you can send the camera back to SK Grimes you can probably have Adam fabricate a custom adapter to whatever tolerances you need.

EDIT: For your amusement, I'll attach a couple of my 6D captures from the 210mm Apo-Sironar-S. Per my notes those should be f/11 and f/22. Processed via ACR with no sharpening, resized only in factors of 2 via bicubic. Dunno what vBulletin might do in rendering it, though.
Thanks for the thoughts and examples! The "slop" and precision is certainly a worry of mine which is why I don't want to invest too much money in this... my memory of working with a P2 is that is was incredibly precise and had no slop, but that was with 4x5 film which is an entirely different proposition. I think I would like to get a P2 anyways since it is a serious upgrade (in both weight and precision) over my f line. I would get an M line or monolith if I could but they are still quite pricey. There seem to be a lot of P2s available out there for pennies on the dollar compared to what they cost when new.

It seems like if I can find (or have SK Grimes manufacture) an Arca Swiss 110mm to Sinar lens adaptor which a hole big enough to not cover any of the sensor area then I can at least experiment with this.

For that Cambo has the DPSB-45 (direct plate for Sinar) adapter plate which can be combined with the SLW adapter needed for the specific back.
Thanks. That looks like exactly what I want, although my preference would be for one that would accept Arca Swiss 6x9 plates since I already have the ones that I need for my technical camera.
 

Oren Grad

Active member
Thanks for the thoughts and examples! The "slop" and precision is certainly a worry of mine which is why I don't want to invest too much money in this... my memory of working with a P2 is that is was incredibly precise and had no slop, but that was with 4x5 film which is an entirely different proposition. I think I would like to get a P2 anyways since it is a serious upgrade (in both weight and precision) over my f line. I would get an M line or monolith if I could but they are still quite pricey. There seem to be a lot of P2s available out there for pennies on the dollar compared to what they cost when new.
For sure, if you anticipate getting some 4x5 use out of it as well, it'll be a very nice upgrade. Good luck, and if you do go ahead with the digital back adapter, let us know how it works out!
 

med

Active member
i'm no certain that an old P is precise enough for a digital back...
I haven't been able to get clear information on this... a lot of searching has resulted in the info from Thierry (Sinar rep that has posted some on a number of forums) that:

a) gears on a P2 (if adjusted properly) should be up to snuff for digital work, although this info is from 2007-2009 or so and may be a different story with today's high res backs.

b) gears on P2 and P3 are identical mechanically, however they are adjusted differently on a P3, whatever that means.

That being said, I'm rethinking this plan and think that spending some extra money and keeping everything in the Arca family makes a heck of a lot more sense for cross-compatibility sake. There's just something about using a tank like a P2 that is appealing to me for some reason!
 

med

Active member
Quick update for anyone that finds this thread in the future... I was mere moments away from buying a Sinar P system when I found a smoking deal on a 6x9 Arca M-Line that will mate extremely well with everything I have and work very well with a digital back.There is still *something* about the Sinar system so I still may buy a P someday. Who knows!
 

Oren Grad

Active member
Quick update for anyone that finds this thread in the future... I was mere moments away from buying a Sinar P system when I found a smoking deal on a 6x9 Arca M-Line that will mate extremely well with everything I have and work very well with a digital back.There is still *something* about the Sinar system so I still may buy a P someday. Who knows!
Congrats, and enjoy! :thumbup:
 
Top