Step Down to 6x9cm?

[Ross Martin]

Hello All,

I shoot a lot of 4x5 transparency landscapes and am considering the tremendous c ost savings in film and processing by switching to 6x9cm (using a roll film back in my view camera). Other advantages would be access to excellent new medium f ormat scanners, ability to easily bracket when needed, ability to use wider aper ture for equivalent depth of field and get faster wind-stoppong shutter speeds, much wider availability of film emulsions, and less weight and bulk of film.

I have rented and used a roll film back but am still undecided. I would appreci ate hearing from any of you who have shot extensively with 6x9 or 6x7 in a view camera (I must have movements). What are the good and bad points in actual fiel d use? How is your print quality compared to 4x5? Do you get used to that tiny ground glass image?

Thanks for your input.

[Mark_437]

My experience with the Calumet C2 back was less than satisfactory. Besides problems inherent to that particular model (sharp bend in film path, uneven spacing, etc.) I found that the accuracy of the rollback-to-camera spacing with regard to film registration had pretty sloppy tolerances (i.e. things weren't so sharp).

I don't see how you can "use wider apertures for equivalent DOF", especially since you'll be enlarging your film to a greater degree for same-size prints vs. 4x5 film.

It wasn't too hard to get used to the GG image. I made a mask out of a piece of (black) scrap 4x5 film to go over the GG.

Good luck,

[Ross Martin]

Mark,

For the same subject magnification and same aperture, there is less depth of field as you move up in film size. For example, without using movements, you would need to stop down an additional 3 2/3 stops in 4x5 to equal the depth of field of the same shot in 35mm. By my calculations you need to stop down about 1 stop less in 6x7/6x9 compared to 4x5, thus offering 1 shutter speed faster and also giving less sharpness-degrading diffraction and more resolution(helping compensate for the fact that you are enlarging your 6x9 more compared to 4x5).

[John H. Henderson]

The conventional circles of confusion used for various formats to calculate depth-of-field already take into account the amount of magnification. (e.g., 0.025 mm may be be used for 35mm, and 0.1 mm for 4x5 [or am I off my an order of magnitude?) Anyway, I think the equations for near distance and far distance are:

near distance = hd/(h+d)

far distance = hd/(h-d)

where h is the hyperfocal distance and d is the actual distance at which you are focussed.

h = f*f/(N*c)

where f is the focal length of the lens, N is the f-number, and c is the circle of confusion.

It's the square of the focal length that causes the big depth-of-field difference between formats even when adjusting c for the amount of enlargement. A "normal" lens for 35mm format is 43mm (f = format diagonal) and is about 150mm for 4x5. Square those numbers and you get a big difference in the hyperfocal distance.

(BTW - look up those equations before you take them as gospel - I'm recalling them from memory. And I think there are simplifications involved that assume that you are focussed many focal lengths from the camera so whether you're measuring from lens board or film plane is no important.)

I haven't tried 6x9 yet, but am tempted to. Your reasons sound good and legitimate. In the end, it's what works for you. I wonder if the difference between 6x7 (or 6x9 or 6x12) and 4x5 is enough to notice for anything I do. I don't see making 30x40 prints. One of my motivations would be to reduce camera size, too, in addition to those you stated. Furthermore, if you go along with the generally-accepted practice of allowing your circle of confusion to get larger as format gets larger, you're cancelling some of the increase in sharpness that you can achieve. That's always bothered me from the first time I read that CoC should vary with format size.

[Paul Schilliger]

Ross, I have used a Wista 6x9 back and the shots are very sharp. I enlarge them up to 14 x 20 with plenty of details (of course a full 4x5 has more detail). I simply marked the corners of the forma t on the sleek side of my GG with a permanent marker. As you say, it's a great cost saving solution, along with the other advantages you mention. Something to consider is the possibility to bracket and to try take from differe nt angles, which leads in more choice and more chances to have a good one. I would highly recommend for stock, unless you use a medium format along with the view camera.

[Jeffrey Goggin]

Assuming you have modern, high-quality lenses, one other benefit of shooting in the 6x? format is that even with movements, you're only using the center portion of the lens, which is usually sharper than the edges. On the other hand, if you own only older, lower quality lenses, as I unfortunately do, then you may notice a slight loss of resolution as compared to your 4x5 originals since 6x9 will have to enlarged more for the same size print. (This is especially true if you intend to crop your 6x9 and 6x7s to 4x5 proportions.)

Although my experience with the 4x5 format is limited, I own a Toyo 23G view camera -- a scaled-down 2x3/6x9 version of their 45G, thus its model designation -- and have plenty of experience with the 6x9 format as I shot with a Galvin 2x3 and Century Graphic in the past. For prints up to 16x24, which is about as large as I've had made, I have no complaints about the 6x9's image quality. Friends have had 20x30 prints made from some of my 6x9 originals and they seem happy enough although IMO, that's probably pushing things a bit too far.

If you're coming from 35mm, as I was when I bought the Galvin a few years ago, the 6x9 ground-glass will seem quite large. Although it does make using a loupe somewhat difficult, I recently abandoned the darkcloth-and-loupe approach in favor of Toyo's monocular viewer.

It isn't all that bulky to carry, is much lighter than a dark cloth, has a built-in low-power magnifier and overall, makes the camera so much easier to use, especially during hotter weather (important here in Arizona!), that I don't know why I waited so long before trying it.

The only complaint I have -- and this is somewhat camera dependent, of course -- is that I find it a PITA to remove the ground-glass in order to mount the rollfilm back. Some cameras, such as the Galvin, let you slide them under the ground-glass, as you can with the film holders on your 4x5, but most require you to remove the ground-glass assembly. I understand that some high-quality backs are thin enough to fit under the ground-glass -- Sinar zoom, Linhof Rapid Rollex, etc. -- but they are also quite costly compared to those from Horseman, Mamiya, etc., hence the reason why I haven't looked into this any further yet.

[Ken Burns]

I have used a Calumet roll film back with my 4x5 field camera quite a number of times. I usually shoot 4x5 B&W, but sometimes I use the roll film back for color transparencies. The only real problem I have had is with the shorter focal length lenses. Since the 6x7's equivalent focal lengths are about half the 4x5's focal lengths, my shortest lens (65mm) doesn't always turn out short enough. In the 4x5 format, 65mm is unltrwide, but in the 6x7 format, it is only moderately wide. This is the shortest lens I can use on my field camera, so if I need a wider lens for the 6x7 format, I'm just out of luck.

[Ellis Vener]

I use a Horseman 6x9cm back on my 4x5 Arca-Swiss and Canham DLC cameras. I've also used the Horseman 6x12 back and the Sinar 6x7cm rollfilm back.

The gross difference is the need for shorter lenses. A 65mm lens with a 6x9cm is the equivalent of a 90mm on 4x5.

The next difference as someone else has already pointed out is the need to use different standards of what you consider sharp --i.e., smaller circles of confusion.

With the 4x5 cameras I don't really feel confined by the smaller groundglass, As a matter of fact it makes it a little easier for me to consider other compositional options. Both the Canham and the Arca have well defined, and for my 6x9 film back, accurate frame markings. But I do take a little more time checking focus. And fortunately the film plane for my Horseman back, for the Fuji Quick Load holder and for the Polaroid 545i back all coincide. This is worth testing.

[Ken Burns]

Actually, a 65mm in the 6x9 format is about equal to a 120mm in 4x5.

[Glenn Kroeger]

Ross:

I liked 6x9 so much, I sold my 4x5 and got an Arca Swiss 69FC. While you might not want to go that far right away, roll film does have its advantages. You are correct that you get approximately 1.2 stops of extra DOF, assuming you use lenses that are about 2/3 the focal length for 4x5

You also get to use just the juicy center of nice lenses. The 55 Apo- Grandagon has the same angle of view of a 24mm on 135. I also like long focal length lenses, and with 6x9, the equivalent lenses are smaller, faster and I have alot less bellows/camera to sway in the wind. Combined with that one extra stop, I get shots I could not get with 4x5 in windy conditions (are there non-windy conditions?).

You also have a wider selection of films, for example some of the new fast color negative films, and Provia400F.

I find that with Velvia and Provia F, scanning on a Tango scanner and printing on a Lightjet, I cannot see a difference unless I go to sizes greater than 16x24. At 20x30 the difference is just barely perceptable, and I can make very satisfying 24x36 inch prints.

Film flatness is critical. I cannot recommend the Calumet backs. I used one for several years on a 4x5 camera with unreliable results. My results with Horseman backs on the Arca are drastically better. If you want a slide-in back, you can try the Toyo if your camera has enough opening under the ground-glass. The Toyo has excellen film flatness but is very thick. Or, the Sinar holders are superb, but very costly.