4x5 vs 6x7 crop

[LMNOP]

Apug!

This has likely been discussed in the past, but I could not find a clear answer in all the debating.

My Mamiya RZ67 Pro ii produces beautiful negatives, but after scanning, I am not exactly clear on how I should be cropping. I, foolishly, entered 6 and 7 into Photoshop's custom constrain field, and while I love the ratio that gives me, I am loosing quite a bit on the edges. Meanwhile, if I go with 4x5, 8x10, etc. I get a ratio that fills the frame with the ability to go ALL the way to the edges on all four sides. This seems like the 'ideal format' in truth, but I can't help but wonder where 67 comes from, if that crop is such a slice on the sides. I'd love some history, or input. What do you guys do?

 

[wiltw]

So-called designations 645, 6x6, 6x7 are approximations.

• The real frame width on 645 depends upon brand, but about 42mm x 55.5mm or 1:1.32 aspect ratio. (Mamiya and Pentax 41.5mm x 56mm, or 1:1.35; Bronica 42.5mm x 55mm, or 1:1.29) ,
• The real frame width on 6x6 is actually 56mm x 56mm.
• The RB67 actual frame size is 56mm x 68.4mm, or 1:1.22 aspect ratio.

The print size on enlarger paper varies a bit due to borderless 1:1.25 vs. bordered print 1:1.26, also, although nominally 1:1.25 aspect ratio.


Don't forget that few enlarger negative holders showed the entire frame, in an effort to prevent contrast destroying stray light leakage at the edges of the image area. And to account for brand-to-brand variances in frame dimensions.

'the ideal format' is a bunch of marketing ploy. One might argue that Bronica's 645 format printed on bordered 8x10 paper is really more 'ideal' than Mamiya 6x7 on 8x10 paper borderless!

 

[Ian C]

The format of a Fidelity, Lisco, or Riteway 4” x 5” film holder is about 95mm x 120mm due to the edges used to retain the film in the holder. So in this case the 4” x 5” format has the aspect ratio 24:19 = 1.26.

The 6 x 7cm format can vary depending on the make and model. The Mamiya RZ67 uses 56mm x 69.5mm with aspect ratio 1.24.

Although they aren’t identical, the aspect ratios of the RZ67 and the Fidelity, Lisco, and Riteway 4” x 5” film holders are quite close to each other.

 

[Denverdad]

Yeah, the 6x7 designation is rather unfortunate from that perspective. On my Pentax 6x7 the actual film gate ratio is pretty darn close to "ideal format" proportions (1.25 aspect ratio), and I think I have read that it was designed for those proportions. Maybe all 6x7 cameras are designed to be close to ideal format? I am sure others will chime in with a better history, but all I know is that 120/220 film is 60mm wide, so it seems that the "6" part of any 6x? format is just a convenient but very rough approximation to the image dimensions. The actual image width (edgewise) is typically more like 56mm.

 

[removed account4]

....

 

[Bill Burk]

I think wiltw is right, the sizes are approximate.

4x5 negatives fill up 8x10 and 11x14 inch paper with a minimum of cropping (or in my case no cropping). Being able to get all of a negative on a print is great when you like what you see, and don't want to waste a drop. (I can easily get carried away discussing black borders and no cropping, if you want to hear more, you could dredge up an old thread)...

I think 6x7 was intended to carry on that proportion with 120 roll film.

It's not only about maximizing the quality (although you do maximize the quality)...

I recently noticed that Kodak Pocket Instamatic frames (110 cartridges) also fits 11x14 inch paper nicely, and I enjoy the two prints that I made for the Monthly Shooting Assignment "Cheap Camera"...

 

[LMNOP]

So based on this information, 6x7 is not a useful figure to the artist, but more of less a marketing classification. I am cropping these images at 4x5, as it maximizes what I get out of the negative.

 

[Bill Burk]

LMNOP,

Sounds like a good idea to maximize what you get.

In case you are wondering whether or not you should crop... I dredged up an old thread for you, where I reveal some of my thoughts about the crop/no crop position...

(there was a url link here which no longer exists)

 

[LMNOP]

I am happy with the 4x5 crop, since it allows maximum inclusion of detail and space. I take my time when composing shots, despite the fact that I have a huge negative to work with, I am very stingy when it comes to frame real estate. I strongly dislike cropping an image to get rid of something in the bottom corner. Here's a shot from my first RZ roll, cropped edge-to-edge at 4x5.

 

[Tony-S]

I, foolishly, entered 6 and 7 into Photoshop's custom constrain field, and while I love the ratio that gives me, I am loosing quite a bit on the edges. Meanwhile, if I go with 4x5, 8x10, etc. I get a ratio that fills the frame with the ability to go ALL the way to the edges on all four sides. This seems like the 'ideal format' in truth, but I can't help but wonder where 67 comes from, if that crop is such a slice on the sides. I'd love some history, or input. What do you guys do?

You're not the only one who thinks 6x7 cameras produce images with a 6:7 aspect ratio. It is a common misconception.

The 6x7 format was developed as a roll-film version of 4x5 and 8x10 view cameras and all of them produce images closer to 4:5 than to adjacent aspect ratios. The difference between 6x7 and 6x6 images substantial - a 6x7 frame is 25% larger than a 6x6 frame and prints without meaningful cropping to the typical papers that are also 4:5 (8x10, 11x14, 16x20, etc.).

 

[removed account4]

So based on this information, 6x7 is not a useful figure to the artist, but more of less a marketing classification. I am cropping these images at 4x5, as it maximizes what I get out of the negative.

i guess now i can ask it

not to cause trouble, but why crop at all ?
when you compose the image, do you use the whole view if so
why crop out part of what you composed to be part of the image?
you suggest you are stingy about maximizing your negative, doesn't cropping it
defeat the whole purpose ?

whenever i use a 2x3 back i usually compose full frame and don't crop, that rectangle
always looks nice on 5x7 and 8x10 with a border ......

 

[LMNOP]

i guess now i can ask it

not to cause trouble, but why crop at all ?
when you compose the image, do you use the whole view if so
why crop out part of what you composed to be part of the image?
you suggest you are stingy about maximizing your negative, doesn't cropping it
defeat the whole purpose ?

whenever i use a 2x3 back i usually compose full frame and don't crop, that rectangle
always looks nice on 5x7 and 8x10 with a border ......

Maybe I was not clear about this, but I personally scan my negatives, so there is a slight bit of cropping involved just to get rid of the edges of negative itself. The way a negative scans in is not perfectly clean, usually an nonuniform black border, with small divots on the corners. You need to crop very slightly to get a clean image. This thread is about which ratio to use in order to get a rectangle that meets all four sides perfectly.

 

[wiltw]

• The RB67 actual frame size is 56mm x 68.4mm, or 1:1.22 aspect ratio.

The 6 x 7cm format can vary depending on the make and model.
The Mamiya RZ67 uses 56mm x 69.5mm with aspect ratio 1.24.

And we can see that Mamiya is apparently not CONSISTENT even within the RB67/RZ67 models!

 

[Ian C]

The reason that the 6 x 7cm format is referred to as “Ideal Format” is that its aspect ratio is about the same as the popular precut enlarging paper sizes: 8” x 10” and 16” x 20”, and isn’t greatly different than 11” x 14” (1.27), and 20” x 24” (1.2).

Thus all or most of the on-film image can fit the print from edge to edge.

For those who insist upon making enlargements that fit the paper with no more than slight edge overlap, continuous roll paper can be cut to length to suit any format.

 

[DannL.]

This may not be useful info, but I personally don't expose with the intent of printing the entire contents of the negative. I leave all doors open for creativity. I try to leave as much "working space" within the frame to accommodate a change of direction. When I expose and while looking at the focusing screen, I try to visualize any number of cropping and framing possibilities. And it's not uncommon to end up with a vertically oriented print from a negative that was originally exposed on the horizontal. And, if you are serious about the outcome of your efforts, you wouldn't hesitate for a moment to take multiple shots of the subject from multiple positions. When I read about those who say they only print "full frame", I tend to ask "why?". That would be akin to writing a book and not allowing yourself to edit the text that you have already written. Why lock yourself into box? Granted, you must work within the restrictions of the cameras design, but the camera manual doesn't state that you can't be creative before and after the exposure.

 

[MattKing]

If you are going to scan, include the edges, and then crop afterwards.

 

[LMNOP]

If you are going to scan, include the edges, and then crop afterwards.

Yes, of course. When scanning, I custom drag the field of capture to include black frame on all sides. I crop within the negative in PS.

 

[removed account4]

Maybe I was not clear about this, but I personally scan my negatives, so there is a slight bit of cropping involved just to get rid of the edges of negative itself. The way a negative scans in is not perfectly clean, usually an nonuniform black border, with small divots on the corners. You need to crop very slightly to get a clean image. This thread is about which ratio to use in order to get a rectangle that meets all four sides perfectly.

nope, you weren't clear about this ( or at least i didn't get it )
if what you do works .. thats all that really counts ...

 

[Old-N-Feeble]

RE 4x5in, 8x10in or 6x7cm having "ideal" ratios: It's only my opinion, and not to derail this thread, but I prefer narrower ratios because 4:5 feels >>>squeezed in<<< to me... at least for horizontal images. With vertical compositions it doesn't matter as much to me. My favorite ratios are 2:3 or 1:2. I've made prints with 4:5 ratios because that was the film format I used and composed the images to use every millimeter. At the time I was a stickler for squeezing every bit of quality I could from every grain of film so I seldom allowed myself the luxury of cropping. That was a long time ago though and film quality is far superior to what was available back then.

My point is, there's no reason to not crop unless the subject fits the format perfectly. I doubt I'll ever pay much attention to ratios ever again.

But.... maybe this is off-topic. Sorry if it is.

 

[David A. Goldfarb]

Linhof introduced the phrase "ideal format" in the late 1950s. The attraction was that it not only printed to 8x10" approximately, but also suited vertical magazine formats of the day. Linhof 6x7 backs are actually 56x72mm.

I'd say it's the rollfilm format I most often shoot, but 6x9 has its attractions (same proportions as the 35mm frame), as do all the others.

 

[michaelbsc]

... I prefer narrower ratios

[...]

there's no reason to not crop unless the subject fits the format perfectly.

With all the talk of ratios, I suspect the average consumer would "prefer" the Golden Ratio - just google for more than you care to know. But that's not the size of any commercial product.

As far as cropping goes, I have often marveled at the prices a 6x12 back for a 4x5 will fetch. I've said on many occasions that there is a perfectly good 6x12 image inside every 4x5 image you take.

 

[DannL.]

Linhof introduced the phrase "ideal format" in the late 1950s. The attraction was that it not only printed to 8x10" approximately, but also suited vertical magazine formats of the day. Linhof 6x7 backs are actually 56x72mm.

I'd say it's the rollfilm format I most often shoot, but 6x9 has its attractions (same proportions as the 35mm frame), as do all the others.

Interesting. If memory serves, I believe it was an engineer at Linhof that coined the term "Large Format" when describing the 6x9 as being the threshold between smaller formats and what was soon to be known as Large Format. Subsequently Linhof used the term when advertising their new cameras in photography magazines. I believe that occurred around '51 or '52. I don't recall ever seeing the term used "in print" prior to that time frame. But, prior to that I do believe it would have been seen as a identification marking (stenciled) on aerial-film crates during WWII. And then . . . I could be making this all up.

 

[Old-N-Feeble]

With all the talk of ratios, I suspect the average consumer would "prefer" the Golden Ratio - just google for more than you care to know. But that's not the size of any commercial product.

As far as cropping goes, I have often marveled at the prices a 6x12 back for a 4x5 will fetch. I've said on many occasions that there is a perfectly good 6x12 image inside every 4x5 image you take.

True but roll film has the edge on two counts: 1) It has slightly better resolution than sheet film., 2. One RFH and a few rolls of film are easier to carry around and use than DDS and a change tent.

In the one hand one could argue that more than one RFH is needed to allow for shooting different types/speeds of film and/or allow variable processing times/techniques for B&W. So this negates the compactness issue. On the other hand and IMO, if an image is worth taking at all then it's worth taking six... use up the whole roll. Lighting can change slightly... one could bracket for DOF or shutter speed... and this gives extra copies in case one or more frames are damaged.

I'm not suggesting 6x12cm is preferable to cropped 4x5. I'm just saying that's my choice.

 

[ic-racer]

I am not exactly clear on how I should be cropping

Why are you cropping?

 

[LMNOP]

Why are you cropping?

I've addressed this already. Not cropping the image other than cleaning up the negative by getting rid of the black edges from scanning.