What is the purpose of a 6x12 roll film back?

[khh]

We did eventually get Phoenix in 120. It's not impossible Harmon will give us Phoenix or it's sucessor in sheets too, eventually.

 

[Sirius Glass]

One of the reasons I purchased a 4x5 camera was a bigger negative. Specifically, I wanted better panoramas, as my current method is cropping 6x7 which doesn't produce a large negative. Looking at my options now I am trying to understand the purpose of 6x12 roll film backs for 4x5 cameras.

If my math is correct, a regular 4x5 sheet is wider than a 6x12 negative. Meanwhile, these roll film backs do not seem as convenient to use as sheet film. You have to focus on the ground glass, then take the regular back off, mount a 6x12 back, etc. Basically smaller negative + slower shooting + extra weight + extra cost. And despite this, they do exist.

I am obviously missing something here. What is it?

I agree that the advantages of having a larger format with 4"x5" film are lost when one uses a 6x12 roll film back. One losses the advantages while having a bulky and harder to handle camera with a medium format film.

 

[GregY]

I agree that the advantages of having a larger format with 4"x5" film are lost when one uses a 6x12 roll film back. One losses the advantages while having a bulky and harder to handle camera with a medium format film.

If your mind's eye panoramic tends towards less than 6x17....6x12 is a beautiful view. Back when 4x5 was cheap...i'd just crop.....but today if i were set on 6x12 (with a wide selection of lenses)...i'd put up with the bulk & inconvenience.
My eye loves 6x8 / 6x12. far more than 6x7/6x9/ 6x17, albeit that a crop of 4x5 allows for many more options at will.

 

[Chuck1]

6x12 is the new 4x5

 

[djdister]

I agree that the advantages of having a larger format with 4"x5" film are lost when one uses a 6x12 roll film back. One losses the advantages while having a bulky and harder to handle camera with a medium format film.

I see lots of advantages. By using a 6x12 back on my 4x5 I can:
- select from many different 120 film emulsions than what is available on 4x5
- use any of my many lenses that my 4x5 uses (like 10+ lenses)
- do critical ground glass focusing and composing for 6x12 shots (compare to the pitiful ground glass of the Horseman SW612)
- use the tilts, swings, rise and fall adjustments of the 4x5
- use Scheimpflug (if I want to)
- easy roll film processing
- 6 shots on each roll using the very reliable Horseman back

Most of these advantages are replicated (except only 4 shots per roll) when I use the Canham 6x17 motorized back on my 5x7. Plus I shoot 5x7 sheet film. Yes, it is more stuff to carry around. I don't shoot enough 5x7 color to justify buying a box or two, but shooting 120 color film using the rollfilm back is easy without a big committment, and then I get color 6x17 panoramas to go along with my B&W 5x7 shots.

 

[djdister]

sorry, I have Autism, so didn't get it, I did it in school English class, so if you said "absolute power corrupts absolutely", Yes, I would have got it, as that's the "one liner" of the movie/book, and the moral of this story. Yes the cost of this hobby is disappointing, but its also a fact of no to low competition as only Fujifilm, Ilford (Harman technologies) and Kodak make film, and the low volume of new film cameras if this improves, maybe the price will follow it?

I'd offer to compare the cost of "this hobby" to buying a boat...

 

[Vieri Bottazzini]

I'd offer to compare the cost of "this hobby" to buying a boat...

The two best days of boat owners famously are the day they buy it, and the day they sell it with photography, as much as I love buying gear, for me the best days are the hundreds of days after buying, the days when I am out in the field with whatever camera I have with me.

Back on topic, I think there is room for 6x12 backs in a 4x5" shooter's kit. Also, carrying a 6x7 (mini-4x5) film back and a 6x12 one would weigh as much as 6 4x5 holders, but one could carry a few rolls and have many more shots, not to mention the ability of changing rolls in the field, as others pointed out. The availability of extra emulsions in 120, with some super-sharp ones that aren't available in 4x5", should help compensate at least to a degree for the lack of real estate in 120 compared to 4x5".

As well, using 6x7, 6x9 and 6x12 on a 4x5" camera body and ground glass allows one to "see" outside of the actual frame recorded, which is great for precise composition (especially with cut-corner 4x5" ground glass) and for precise focusing, since it allows one to use a loupe right to the corner (and past), whereas with 4x5 the frame around the ground glass makes doing so much harder.

Last, if one needs to fly, it seems that carrying roll film makes it easier to have it hand-inspected compared to 4x5", which might be a plus as well - I know it might be for me, which is why I am considering adding a 35mm lens to my 4x5" kit (to replace the 47mm and 55mm I am using with 4x5"") and travel with roll film on my fall tour... better having less real estate, than having my film nuked my a CT scan machine!

But, the beauty of a large 4x5" sheet is of course something else...

Best regards,

Vieri