Arca Swiss 6x9 rollfilm back for Arca Swiss Field Camera

[JPlomley]

I'm interested in a roll film back mainly for macro photography. Looking at B&H's website, it appears as though the Arca Swiss 6x9 roll film back is just a rebadged Horseman with an extra $250 added. Exactly what are you getting for that extra $250. Does Arca make any mods for better film flatness? Or tighter tolerances on the position of the film plane when the back is attached to Arca Swiss cameras?

[Bob Salomon]

Linhof makes the tightest spec ones with the flattest film characteristics. But they are also the most expensive.

[Gordon Moat]

KEH (http://www.keh.com) sometimes have rollfilm backs in their used gear selection. I got my Linhof Super Rollex from them, and it has worked extremely well without any problems.

Ciao!

Gordon Moat Photography (http://www.gordonmoat.com)

[Phil Hudson]

I don't know the exact answer to whether Arca-Swiss make any modifications or not, but I have a couple of each (Horseman and Arca) and they look identical inside and out (except for the sticker).

I have never had any particular film flatness issue with either one and I use them interchangeably, although one suspects that it is not perfect due to the visible film curl when the darkslide is out.

Phil

[JPlomley]

Cheers Gordon. What is a reasonable price for a used Super Rollex in Mint condition?

[Capocheny]

Hi JP,

Like Gordon, I also use a Linhof Super Rollex roll film holder... and have done so on my Sinar for years. IMHO, they're the best on the market. The lever action is very smooth and not jerky like others I've had in the past.

[You can also find the "knob" version but I think they're quite a bit older than the lever version. Perhaps, Bob can confirm this.]

If you're looking for a used one... they can certainly be had for a very, very reasonable price.

Check with Jim at www.mpex.com or Jeff at www.badgergraphic.com.

Lastly, they're extremely well-built and made to last! :)

Cheers

PS: I've seen them go between $175 to $250 on the bay.

[Gordon Moat]

Mint condition Linhof Super Rollex . . . probably anything under $US 400 would be a good deal. The tan leather versions tend to be the older style than the black leather versions. There are two lever wind versions, one with a flip up knob at the lever tip, and the other more like the modern version with a solid metal lever. The really old knob wind versions are best avoided, both due to age, and because the design tends not to be as even in film frame spacing as these see more usage.

Anyway, it appears that KEH has one in stock in EX- condition. This is a newer style lever wind with black leather covering. When you see eight (8) shots, that means their 6x9 version, and ten (10) shots would be the 56mm by 72mm or 6x7 (which is what I use now).

Ciao!

Gordon Moat Photography (http://www.gordonmoat.com)

[JPlomley]

Cheers gentlemen. Gordon, I'm going to place the order tomorrow with KEH.

As an aside, is it necessary to perform any sort of calibration (focus offset) for the film plane? Apologies for the newbie question, but this is my first roll back for a 4x5.

[Ted Harris]

OTOH, you can buy a new Horseman 6x9 back from Midwest for the same price as a used Super Role. I have used both Linhof and Horseman backs and actually prefer the Hrseman. While agreeing that the Linhof likely has tighter tolerances I have ever seen any problems with the Horseman.

[Gordon Moat]

On the Linhof Super Rollex backs, there is a slot like hole in the top centre of the backing plate. When you load the film, you should be able to see the arrow on the paper through that hole. If you do that, then you should be able to get even frame spacing, and get all eight shots before running off the edge of the roll. You might want to use a wasted/expired roll for practice, just to be sure you are loading it properly. Remember not to force any of the controls; the back should work very smoothly without undue effort required.

Ciao!

Gordon Moat Photography (http://www.gordonmoat.com)

[JPlomley]

Cheers Gordon. What about positioning of the film plane? Once focus is achieved on the GG and I switch to the roll film back, do I need to apply a focus shift, or is the film plane spot on?

[Oren Grad]

Cheers Gordon. What about positioning of the film plane? Once focus is achieved on the GG and I switch to the roll film back, do I need to apply a focus shift, or is the film plane spot on?

There used to be a page on the medium-format megasite that had information on this, but it seems to be down now, so I'll paste in a relevant chunk here. The last number on each line is the film plane register for the respective model of roll holder:

Model - Type - Formats - Film - Depth
Cambo slide-in 6x4.5 120/220 4.95mm
Cambo slide-in 6x7, 6x9 120/220 4.95mm
Cambo slide-in 6x12 120/220 4.95mm
Horseman clip-on 6x7,6x9 120 4.95mm
Horseman clip-on 6x7, 6x9 220 4.95mm
Horseman clip-on 6x12 120 4.95mm
Linhof S-Rollex clip-on 6x7,6x9 120 4.85mm
Linhof Rapid Rollex slide-in 6x7 120 4.85mm
Linhof Techno-Rollex clip-on 6x12 120/220 4.85mm
Sinar Zoom slide-in 6x4.5 to 6x12 120/220 4.85mm
Sinar standard slide-in 6x7, 6x9 120/220 4.85mm
Toyo clip-on 6x7,6x9 120 5.05mm
Wista clip-on 6x7, 6x9 120 5.10mm
Wista Type DX slide-in 6x7, 6x9 120 5.10mm

The ANSI spec for depth to film surface for 4x5 holders is 0.197", which is equivalent to 5.0038mm. You can decide whether the theoretical discrepancy between this and the various numbers for the different roll holders is enough to worry about. ;) I suspect that in virtually all roll holders, unevenness in the surface of the film itself contributes as much or more slop. Over the years I've owned various roll holder models from Cambo, Horseman, Linhof, Sinar and Toyo, and have never seen any systematic focus problem with any of them in my typical usage, which is with distant subjects and middling to small apertures.

[Bob Salomon]

Linhof Techno-Rollex clip-on 6x12 120/220 4.85mm

The Techno Rollex is 120 only. You can buy a conversion cassette to hold 220 film. But out of the box it is 120.

The Super Rollex 67 back is available as a 120 back or as a 220 back or you can buy a spare insert to convert from one to the other.

[Gordon Moat]

Cheers Gordon. What about positioning of the film plane? Once focus is achieved on the GG and I switch to the roll film back, do I need to apply a focus shift, or is the film plane spot on?

You could measure it with a dial caliper, which is basically what I did when I got mine. I found it matches my Fuji Quickload and Kodak Readyload set-ups, as well as the ground glass focus distance. Besides, it has to be accurate enough to do this:

http://www.gordonmoat.com/swops/GM_swop_24.jpg

This is a crop of a 56x72 frame. Selective focus was done by using tilts, and the talent was instructed to stay along a line parallel to the camera. The full shot (http://www.gordonmoat.com/life_04.html) shows a bit more of the selective focus, though due to being vertical orientation does not show as much detail.

Ciao!

Gordon Moat Photography (http://www.gordonmoat.com)

[Oren Grad]

So there are two questions here.

The first is whether there's a systematic offset between the standard for 4x5 film holders and the standard(s) for roll holders. Per the numbers I posted above, the answer to that is evidently yes, though you'd have to figure out whether the possible discrepancy matters relative to the depth of focus and required focus accuracy typical of your applications.

The other question is whether your 4x5 camera is built accurately to ANSI standard. That can't be taken for granted. So if you really do have ultra-critical requirements, you'd better measure and/or test everything - though measuring to this level, even with a good depth micrometer, is tricky when the pieces flex under pressure, as film holders and camera backs do.

Again, though, calculate the depth of focus you're going to need for your intended applications, and think about how critically you focus in the field, and how rigid your setup is, before you lose too much sleep over it.

[Emmanuel BIGLER]

Hello from France and happpy New Year to all.
My 0,02 euro to the discussion, regarding tolerances on film plane positioning.
The classical model for depth-of-focus suggests that the depth of focus can be computed as

DoFoc = plus or minus N.c

where N is the numerical aperture (effective numerical aperture in macro) and c the required diametre of the circle of confusion.

If we demand c = 50 microns on rollfilm like for classical DoF tables in 6x6 format, which is very strict for 6x9, @f/8, N=8, the tolerance is plus or minus 400 microns.
Taking into account that most LF users will actually stop down to a minimum of f/11, adding to this the fact that we sometimes work in the close-up range (at 1:1 magnification ratio, the effective numerical aperture N is doubled with respect to what is engraved on the ring, hence the tolerance is doubled) the question of accurately positining the film plane has to be revisited in a more relaxed way. Take it easy !

Sure, people using a 2.8-100mm planar (e.g. for the baby linhof) at full aperture, however, do have to take care about where their film plane is located, hence the tight tolerance in Linhof rollfilm backs, remember the good old days where people used a Linhof-selected, 135mm f 3.5 planar at full aperture on a daily basis ;)

And about bulging effects of the backing paper in 120 rollfim, remember that Chris Perez has measured 96 line pairs per millimetre @f/8 with a freshly recalibrated Rolleiflex TLR on 120 rollfilm.
So in any case if bulging effects occur, and they are probably bigger in 6x9 than in 6x6, remember the figure of plus or minus 400 microns at f/8 !! And even if we demand c= 25 microns, like in 35 mm photography, we are left with a comfortable range of plus or minus 200 microns @f/8.

Now the issue is : what level of confidence can we put in the conventional model of DoFoc, based on geometrical optics ?
Recently with the help of friends who are lucky enough as professional photographers to have a full range of digital view camera lenses and a digital medium format back (to the best of my knowledge, silicon is not prone to bulging, at least in digital backs) we conducted a comprehensive range of manual focusing tests with a monorail view camera by recording many images at different positions of the focusing knob. Call it : bracketing with focus or whatever. The series of test is performed much quicker with a digital back than with film of course.
The conclusion is simple : when all lenses are stopped down to the same numerical aperture, namely we used f/11, the tolerance on film positioning, measured by reading the sharpness of test targets, is the same for all focal lengths stopped down at f//11, exactly as predicted by the geometrical model and the approx tolerance we derived from our tests matches perfectly the classical value of plus or minus N.c, no mystery.
There was no digital processing/edge enhancement of the image files, this is important since the test is definitely biased as soon as some edge enhancements of any other digital sharpening are applied before reading the test targets.

[JPlomley]

Oren/Gordon,

Thanks for the valuable information.


Again, though, calculate the depth of focus you're going to need for your intended applications, and think about how critically you focus in the field, and how rigid your setup is, before you lose too much sleep over it.

My application is landscape photography and therefore I tend to be stopped down mainly between f/22 -f/45. I focus very critically in the field using the focus spread technique, referencing the mm scale on the monorail. My set-up is extremely rigid since I added an "extension bracket" (poor nomenclature on the part of Arca Swiss) which nests the optical rail. This bracket than slides into a Z1 ballhead which sits on a Gitzo 1321 Leveling Base, itself secured to a 5-series Aluminum Gitzo pod (total weight of pod + levelling base + ballhead = 11 lb). I realize this is overkill and will likely pick up a carbon fibre pod this spring. The current tripod was purchased almost 15 years ago before carbon fibre came on the scene. At the time I was shooting wildlife with 300/2.8 and 600/4 lenses on Wimberly heads, so just got used to carry a heavy support system.


The other question is whether your 4x5 camera is built accurately to ANSI standard

Well, it is an Arca Swiss, so I would hope for some semblance of precision given their reputation. Perhaps not on par with a Linhof though.

[JPlomley]

The conclusion is simple : when all lenses are stopped down to the same numerical aperture, namely we used f/11, the tolerance on film positioning, measured by reading the sharpness of test targets, is the same for all focal lengths stopped down at f//11, exactly as predicted by the geometrical model and the approx tolerance we derived from our tests matches perfectly the classical value of plus or minus N.c, no mystery.

Emmanuel, nice tests. Hard to argue with practical results. You now have me wondering if I should purchase a few dedicated digital lenses for the 6x9 back.

[Emmanuel BIGLER]

My application is landscape photography and therefore I tend to be stopped down mainly between f/22 -f/45.

... hence the expected DoFoc even with a very strict circle of confusion of 25 microns will be
plus or minus 550 microns@f/22
plus or minus.... well @f/45.... diffraction definitely occurs so the geometrical model, for sure, is no longer valid.... but the image is gradually blurred by diffraction ; OK, roughly, expect someting like plus or minus 1 millimetre !
Even a non-ANSI standard home-made camera can achive this level of tolerance ;)

[Emmanuel BIGLER]

You now have me wondering if I should purchase a few dedicated digital lenses for the 6x9 back.
During the test I have played with some Rodenstock "digital" beasts, including the recent, impressive and (somewhat) extravagant 28mm HR lens (OFF-TOPIC !! does not cover 6x9!!) but not enough to make serious conclusions about the use of those dream lenses on film.
Frankly, so far with an Arca Swiss camera (6x9 plus the 4x5 kit) I'm very happy with "film" lenses.
Including, for example, the classical 75mm 6.8 grandagon-N, a discontinued "film" lens designed for 4x5", so compact and light, so sharp, perfect for 6x9.
Taking into account the excellence of availables "film" lenses in the range of focal lengths from 35mm to 135mm, I am not sure that the purchase of the digital series actually make sense for film use, even if for example, the MTF performance of the last 70mm Rodenstock lens seams, at least on paper, incredible.
The real concern, if you want to scan your images, is that you'll have to use an expensive professional scanner in order to extract all the quality of what those classical film lenses are capable ; it will be even more difficult with "digital" lenses !

This question of scanning medium format images can be considered as a major drawback of using 6x9 instead of 4x5". With a 4x5" image you can use an "amateur" scanner and get more than acceptable results (depending of course on the size of the final print !).
The smaller the image, even if you use the best film and the best lenses, the better you have to scan them if you insist on processing them digitally (may the error is there ;) stay analog+enlarger+wet darkroom !)
So in a sense, 4x5" and above can be consider as amateur formats of the digital age, in the sense : film formats that the amateur can decently scan with an amateur-grade scanner (e.g. one of the good flatbeds available today).

[Oren Grad]

You now have me wondering if I should purchase a few dedicated digital lenses for the 6x9 back.

Many of the "digital" lenses won't cover 6x9.

I have the 90mm Apo-Sironar-Digital, which I think was the first view camera lens labeled as a "digital" lens. It covers 6x9 with room for movement, and is absolutely stellar in every way. Then again, my ordinary 75/6.8 Grandagon-N and 100 Apo-Sironar-N, when stopped down, are excellent too. If you're working at f/22 - f/45, you're not necessarily going to see much advantage from a "digital" lens.

[JPlomley]

This question of scanning medium format images can be considered as a major drawback of using 6x9 instead of 4x5".

Depends what scanner we are talking about. For an Imacon scanner, maximum resolution is 2,040 ppi for 4x5. For for 6x7/6x9 it is 3200 ppi. So quite comparable file sizes.

[Larry Menzin]

It makes sense to use digital lenses with film if you are doing double duty with a digital back. The 90mm APO Sironar Digital covers 4x5 with room for movements. I've gotten great results this past weekend. The 55mm APO Sironar Digital covers 6x12 with room for at least 10mm rise. The 55mm requires the strong (5x) center filter when used with film to get even corner illumination with Velvia 50.

[archivue]

on my arca 69 i prefer Mamiya RB Pro S motor drive 6x8 back !
and the good think with 6x8... 9 pics per film that is a panodia !
6x8 fits in the 67 panodia stuff !

[mdd99]

I use the Calumet C2N and have no problems with film flatness.

[David Karp]

I don't know if A-S makes any modifications to the Horseman holder, but I do know that my Horseman 6x7 holder works just fine on my A-S Discovery.

[hoffner]

Grab the Horseman, forget the AS specimen. A wise decision. You have nothing to loose.