6x4.5 vs 6x7 Film Size

[barry_r]

<p>I've been contemplating a medium format film camera for landscape/nature photography, and with all my reading to date I still can't get beyond the initial choice of film size, in particular 6x4.5 or 6x7. Image quality and size are two main issues for me.<br>

I know this has been discussed many times but so far I haven't been swayed one way or the other. I keep reading that 6x7 negatives and slides are "huge" and somehow "magical" and that 6x4.5 is not such a big step up from 35mm. When the 6x4.5 and 6x7 sizes are displayed next to each other with the "6" sides parallel, of course the 6x7 looks significantly bigger (7 vs. 4.5). For the image below, the grey area is based on the actual dimensions of 6x7 film and the black area the same for 6x4.5, both in landscape format. Unless I've done something wrong, the 6x7 is larger of course but somehow the word "huge" would not come to mind. And indeed, the area advantage of 6x4.5 over 35mm is significantly larger than that of 6x7 over 6x4.5.<br>

Also, the argument usually comes down to how large a print you can make. But the 6x7 lenses appear to be generally slower than corresponding 6x4.5 lenses. Thus, with 6x4.5 one could use lower ASA film. Wouldn't that in some way negate 6x7's slightly larger size?<br>

I'm not trying to make an argument here for 6x4.5, just trying to understand whether the apparently not very significant increase in film area would justify, for me, hauling around the significant increase in bulk and weight of, say, a Mamiya RZ67.<br>

<img src="https://lh3.googleusercontent.com/-rtbospJmQv4/VnNkGR7WezI/AAAAAAAAHZU/qm3Cw4w2DdU/s67-Ic42/645%252520and%25252067.jpg" alt="" /></p>

[SCL]

<p>Either will enlarge quite well - I wouldn't obsess over the differences in negative sizes. If weight is an issue in your photography, go with the smaller size and learn to use it well. Think of how many professional photos for over half a century have been shot with the Hasselblad system in 645.</p>

[gareth_williams2]

<p>I use an RZ but if i were to specialise in close up would go for the smaller format. 67 plus tubes and a hood finder is a pain except for occasional use.</p>

[dan_fromm2]

<p>If you want a modern SLR with lenses that stay open for focusing and composing and stop down automatically when the exposure is taken then the largest readily available format is 6x8 (Fuji GX680 and relatives), next smaller is 6x7, then 6x6 and finally 645. Good cameras with good lenses are available for all these formats.</p>

<p>I prefer 6x9 but there are no modern SLRs for the format. I started with 2x3 Graphics (cheap, cheerful) and later was gifted a 2x3 view camera (free, heavier, more flexible). If the pictures you want to take don't require rapid setup and shooting then you should consider a 2x3 (= 6x9) press, technical or view camera. If, however, you need to work rapidly none of these will suit you.</p>

<p>One of my friends moved up from 35 mm Canon SLRs to a Pentax 645. He was delighted with the results he got with the 645 but seeing some of my 2x3 Graphic shots deflated him a bit. 645 is half frame 2x3. 645 chromes look punk next to 2x3s. To be fair, 2x3 chromes look punk next to 4x5s.</p>

<p>All this said, the larger the format the larger and heavier the gear. Think about how heavy a load you're willing to carry.</p>

<p>In his book Field Photography, A. A. Blaker makes the point that a move up in format that doesn't at least double both dimensions of the frame isn't worth the bother and expense. With that in mind, 6x7 is almost twice as large as 24x36 in both dimensions, 6x9 is larger in both dimensions. 645 doesn't come close.</p>

[peterbcarter]

<p>If weight and quality is your concern..........try a light 4x5, like a crown or speed graphic. I would guess about 1/2 the weight of a RZ, or even my M645J with motor drive.</p>

[dave_s]

<p><em>>>I would guess about 1/2 the weight of a RZ,</em><br>

<em><br /></em>That's a very close estimate! <br>

-An RZ67, with normal lens and a film holder, is 2495 grams (or 5lb 8 oz.)<br>

-A Century Graphic, with lens and no holder, is 1162 grams. Add maybe 100 grams for the rollfilm holder, so, say, 1260 grams (or 2lb 13 oz).</p>

<p>FWIW, I have an RZ, as well as too many other cameras. When the dust clears, I usually end up using my Rolleiflex E (1120 grams). Good backpacking camera. When I want wide, I stitch. When I want long, I crop. Life is a series of compromises. </p>

[peterbcarter]

<p>I shoot with a friend of mine that uses a crown.....and I lug a M645j. Sure I can shoot more frames, but he still get's the one he wants all the time.</p>

<p>I never thought of a roll back.</p>

[mike_earussi1]

<p>The larger the neg the higher the quality of the final print. Any print that's over 4x enlargment you can see the difference in neg size. I've shot 645, 6x6, 67, 69 and 4x5 and the wow factor really only comes with the 4x5 (unless you're just printing 11x14s).</p>

<p>If you're wanting to stick to MF due to size considerations then the lightest and smallest 67 camera would be best. That would be the Mamiya 7 II, if money is no object. It also has the highest quality lenses ever made for MF.</p>

<p>But if money is tight then you should buy the Koni-Omega with the 90mm lens. The lenses are almost as good as the Mamiya but are usually about 1/10 the price. It weighs a lot more, though.</p>

<p>Also, always shoot landscapes using the slowest possible film and on a tripod if you're wanting the highest quality possible. Handholding is fine for sports, weddings, and anything else that moves, but unless you're just shooting for fun, using a tripod is the only way to shoot. </p>

[brian_schall]

<p>What aspect are you going to be printing? Enlarge 6x7 full frame and you get the standard 8x10, 11x14, 16x20. If you are used to printing full frame 35mm, getting 8x12, etc., then 6x4.5 is closer. It's a lot like the difference between 4x5 and 5x7, they look a little different. I shoot a RZ67, replaced my 4x5 and my 6x6 outfits. I still like the aspect of 35mm better for landscapes.</p>

[barry_r]

<p>"What aspect are you going to be printing? Enlarge 6x7 full frame and you get the standard 8x10, 11x14, 16x20."<br>

Good point. I never really liked the 3:2 aspect ratio of my digital cameras. It was sometimes hard to coax an image into 8x10 or 11x14, which are the sizes I have usually been printing up to now.</p>

 

[iangillett]

<p>"But the 6x7 lenses appear to be generally slower than corresponding 6x4.5 lenses. Thus, with 6x4.5 one could use lower ASA film."<br>

While this is true, how often are you likely to be shooting wide open? Most of the time you will be stopping down to at lest f8 or f11, at which point the maximum aperture doesn't come into account.<br>

I have Mamiya 67 cameras (RZ and 7ii) as well as a Pentax 67ii, although I don't use them as much as I should. I've just (flat-bed) scanned a film I shot with the 7ii and a 43mm lens and I am really pleased with the results.</p><div></div>

[jose_angel]

<p>Of course this topic appears from time to time, maybe because it`s somewhat difficult to accept that a larger area, even being noticeable larger, doesn`t mean much higher resolutions. This is real, is not matter of convenience or whatever. The resolution increment is simply minimal by maths.<br /> As Dan says, you may need to double both dimensions (or to double the format diagonal) to make an upgrade really worth it. And I`d say sometimes it isn`t worth it anyway.<br /> The diagonal of the 6x7 format is around 1.2 times the 645. And it`s not only such small difference; shooting film is highly "variable", so I can use many film&developer combinations, some of them will simply negate this small advantage. Gear quality also counts.<br /> On the other side, the larger the negative the "more pleasant" to work with... as has been widely advertised, the 6x7 format on a light table is nice to see (good for chromes, which BTW I never shoot since the advent of digital), and fits right on current paper cuts. I don`t believe in "magical" attributes. Does it make a difference for you?<br /> As you already know, the main drawback is size and weight. Despite of what some people say, some 6x7 reflex cameras are not designed to work hand held (even though some consider themselves strong enough to use them this way), nor to be easily portable (some cameras have delicate parts). But they work great on tripods, and have loads of accessories.<br />It makes 645 cameras a good compromise; they are almost 35mm (portable, metered, AF, etc.), but use roll film, interchangeable backs, larger finders, etc.<br /> Don`t put 6x6 cameras away... some square format cameras have all the advantages of a 6x7 (some even more) on a considerable smaller package, closer to 645 (portability, hand held ability).</p>

[david_henderson]

<p>I used MF for quite a few years and don't agree with a perception that an upgrade isn't an upgrade unless it doubles the film dimensions. Or any other such homily. I don't agree with it in digital either. A 67 neg or slide is 70% larger by area than a 645 equivalent. That's not "slightly larger" its much bigger. In fact in absolute terms you'll gain as many sq mm by moving from 645 to 67 than you would by moving from 35mm to 645 That can be worth a lot provided that you're going to make use of it- like projection or big prints. Or occasionally want to crop to square. If what you want to do with your MF originals is make medium sized prints ( maybe 16" x 12", or scan them to get them on screen then you may well be lugging a lot of extra weight around for little real benefit.</p>

<p>You ought also to consider proportions and flexibility. As someone who always found the "35mm" 3:2 ratio angular and sometimes difficult to compose to, especially for verticals, I find 67 ( and 6x6) suits me much more - more than a 645 which I find visually closer to a 35mm frame. Having been commercially pretty much forced to adopt FF digital, its the format of my MF cameras I miss the most. Also you can get a 56mm sq from a 67 camera , by only 42mm sq from a 645. </p>

<p>I do however think that absolute weight is an issue. Think about whether you're going to be content with one lens or whether (in a market where in general prime lenses are still most often what's used) you're going to end up with four or five lenses in the bag as I did. That's going to make a lot of difference and the weight of a 67 outfit in total may well exceed that of a 645 by several pounds. If you don't project images, or make big prints, you might not get value for that weight.</p>

 

[henryp]

<p>When I shot film full time I had 35mm (Nikon) 645 (Bronica) and 67 (Mamiya RB). My wife could always tell which prints were from 35mm (all else being equal) but was never able to tell 645 from 67 presuming the same subject in the same lighting with the same film type and exposure. YMMV</p>

<p>Henry Posner<br /><strong>B&H Photo-Video</strong></p>

[Ed_Ingold]

<p>645 camera have the advantage of handling much like a 35 mm camera. Most have an eye-level viewfinder, and are easily used in either the horizontal or vertical position. Some have auto focus and most have auto exposure of some sort. The negatives are nearly twice the size of 35 mm film, which is not a bad thing.</p>

<p>6x7 cameras are much larger than either 645 or 35 mm cameras. Some, like the Pentax 67 and Mamiya 7 are configured to be used at eye level by default. As a rangefinder camera, the Mamiya is better suited for travel and landscapes, compared to 6x7 reflex cameras. The lenses are much smaller too, and of the highest optical quality.</p>

<p>In between is the 6x6 format of Hasselblad, Bronica and Rolleiflex. The cameras are much smaller than 6x7 reflexes, and proportionately lighter. So many Hasselblads were produced that used gear is widely available (but getting scarcer). Nearly all makers of MF digital backs have models which fit Hasselbad V bodies. At $20 or more a roll for film and processing (only), a 16 MP digital back is about the same cost as 400 rolls of film (50 MP = 600 rolls).</p>

[rodeo_joe1]

<p>David. Area increments are meaningless. Only linear dimensions are relevant to an increase in image quality. Such that you need approximately 1.2 x more enlargement to get a 645 negative up to the same long-side dimensions as a 6x7 negative. The relative amount of enlargement needed is the true measure of quality, and the fact that area increases by a square factor is simply a function of the maths involved. It doesn't reflect any measurable quality increase. And besides the area increase is only 62%.</p>

<p>I'd also argue that comparing the diagonal of the two formats is misleading. 6x7 has an aspect ratio of a little over 6:5, while 645 has a 4:3 aspect ratio. So the "quality factor" depends upon whether you compare the long side or the short side of their frames. A short side comparison gives an advantage of 1.3333 to 6x7. But no way can 6x7 be said to be 62% better than 645 simply based on area. That's a mathematical fudge that just doesn't wash.</p>

<p>If someone were to claim that a 24Mp digital camera had twice the resolution of a 12Mp camera with the same aspect ratio, then it would be immediately obvious that their claim was fallacious.</p>

[baisao]

<blockquote>

<p>Don`t put 6x6 cameras away... some square format cameras have all the advantages of a 6x7 (some even more) on a considerable smaller package...</p>

</blockquote>

<p>I love my 6x7s but even the Mamiya 7ii is larger than I want to carry every day. I can fit 2 TLRs into the same small rangefinder bag I use for my 35mm rangefinder. It's hard to beat a TLR when it comes to size of the camera and format. Yeah, some people don't get on with them and I resisted using them for years, but I have found TLRs to be practical and the 6x6 format liberating. </p>

[allan_jamieson2]

I've used a Bronica ETRS 6 x 4.5cm, various Pentax 6 x 7cm models and a Fuji GSW690 II (6 x 9cm). The image quality

of all of them was very good but for looking at the transparencies on a light box, bigger is better every time.

 

A Mamiya 7 outfit could be very nice with a 50mm and 80mm or maybe 43mm and 65mm. But the so called Texas Leica,

alias Fuji GSW is an incredible camera for the money, albeit one with a fixed 65 mm lens roughly comparable to full frame

28mm horizontally but less wide vertically. For experimenting with a lighter weight option like the Bronica ETRS/i models

would also be very good.

[barry_r]

<p>Thanks all for the responses. Despite the lack of a totally conclusive argument for either format, I've decided to go 6x7 so as not to regret having possibly compromised. Helping in this decision was that I just purchased what looks like a very nice Bronica GS-1 on eBay, and it appears there's a significant reduction in bulk and weight to the Mamiya RZ-67 that I was considering.<br>

Ian - what scanner do you use?</p>

 

[ondebanks]

<blockquote>

<p>I keep reading that 6x7 negatives and slides are "huge" and somehow "magical" and that 6x4.5 is not such a big step up from 35mm.</p>

</blockquote>

<p>Only people who've never done the simple calculations would say such a thing. 645 is 2.7 times the area of 35mm (gain of 170%); 6x7 is 1.7 times the area of 645 (gain of 70%). The step from 35mm to 645 is decisive; ask anyone who has shot both. If you print them both in any aspect ratio from 4:3 down to square 1:1 (including standard dimensions of 10x8, A4 etc.), the cropping now makes the usable area of 645 exactly 3.0 times larger (gain of 200%) than the usable area of 35mm.</p>

<p>In film, I've shot 35mm, 645, 6x6, 6x7 and 6x9. Out of these, I now only shoot 645. The others were bigger, sure; their quality was generally a little better; but other factors like lens choice, lens speed, handling, camera features, and digital compatibility win the argument in favour of 645 - for me.</p>

<blockquote>

<p>The [645] negatives are nearly twice the size of 35 mm film, which is not a bad thing.</p>

</blockquote>

<p>Given the actual numbers I've quoted above, "nearly thrice" would be a lot more accurate!</p>

[ondebanks]

<blockquote>

<p>In fact in absolute terms you'll gain as many sq mm by moving from 645 to 67 than you would by moving from 35mm to 645</p>

</blockquote>

<p>That's true, but like anything else, impact depends more on relative change than on absolute change. Give an extra €40k annual income to someone who has been making €20k and that boost to €60k makes a massive difference to their standard of living; give the same €40k to someone who has been making €60k already and the boost to €100k has a large but more nuanced impact. (I chose those numbers because they are in the same proportion as the usable frame areas of 35mm, 645 and 6x7). </p>

[rodeo_joe1]

<p>Ray, as I pointed out a few posts ago, area is a meaningless parameter as a measure of image quality. So would you say that a Shenhao panoramic shot of 56mm x 168mm had 3 times the quality of a 6x6cm camera? Because it certainly has 3 times the area.<br /> Very debatable huh?</p>

<p>And how much more enlargement does a 56 x 42mm negative need to bring it up to the same <em>area</em> as a 56 x 68mm negative? Only 1.27 times more, that's all. And that's the real quality difference. A mere factor of 1.27 times, not 70% or even 62% (the actual increase in area between 645 and 6x7 if you do your maths right!).</p>

[david_henderson]

<p>You keep repeating the same stuff, and I still don't buy it. If I've got 70% more celluloid, that's 70% more image. You get the benefit both ways. More length, more height. What you have to do with an enlarger to get there is what's irrelevant- it measures method not result.</p>

<p>62% is wrong too, though the extent of that depends on the type of 67 camera you're using. I measured my Mamiya slides before my first post at 56.25 x 70.5 or 3966sq.mm. A 645 frame is 56.25 X 41.5- though some say 42 or 41- or 2334 sq.mm. That's 70% bigger. </p>

[rodeo_joe1]

<p>David, as long as you keep ignoring the facts, I'll continue to try and educate you.</p>

<p>Any and every objective measure of image quality is based on <em>linear</em> (one dimensional) parameters or criteria.<br>

Grain, or rather granularity, is measured in "roughness" by scanning an evenly fogged negative or slide with a micro-densitometer in a linear fashion.<br>

Likewise resolution is measured in Line-Pairs per Millimetre (<strong>not</strong> resolvable squares per square millimetre).<br>

MTF is measured as a contrast factor over a series of spatial frequencies linearly across the image circle (or %contrast v cycles/millimetre v frame height in simple parlance)<br>

Acutance is measured as the micro-variation of density normal to a contrast step.</p>

<p>In short the area of the film doesn't enter into any scientific measure of IQ. It's simply dependent on the degree of magnification applied from camera image to print.</p>

<p>As an example: We make a 10" x 8" print from 35mm, 645 and 6x7 negatives (while trying to ignore their different aspect ratios). To make things simple we'll leave a margin around the print such that the 24mm x 36mm negative is enlarged exactly 8 times - and consequently cropped across the overlong side. We'll also say that we need 8 lppmm on the final print as a measure of excellent resolution. Therefore the 35mm negative and lens used is required to have a resolution of 64 lppmm <em>across the whole frame</em>. This is a high demand for any lens/film-grain combination, and is probably not easily achievable.</p>

<p>Now let's move to the 645 (56mm x 42mm) negative and make a 10x8 print. The short side of the print is made 192mm - as per the previous print. The enlargement needed is therefore 192/42 =4.57x. And to get our 8 lppmm on the print we only need 36.6 lppmm across the negative, which is a much more practically achievable figure. So there's no reason why our 10x8 print from 645 shouldn't be visually excellent.</p>

<p>Finally we put the 6x7 (56mm x 68mm) negative in our enlarger, and discover that we need to enlarge it 3.43 times. Unfortunately the long side of the negative falls short of filling the 10x8 print, but we'll ignore that. The resolution required of the negative is now 28.2 lppmm and again that's a very realistic figure.</p>

<p>So if we translate all the above into "quality factors" we see that:</p>

<p>1) The print from the 35mm negative probably falls short of "excellent" quality.</p>

<p>2) The 645 negative has a quality factor of (8/4.57) 1.75 times that of 35mm film.</p>

<p>3) The 6x7 negative has a quality factor of (4.57/3.43) 1.33 times that of the 645 negative - except that we don't get a full 10" x 8" print.</p>

<p>4) With the same degree of enlargement we get a 12" x 8" print from 35mm; a 13" x 17.5" print from 645; and a 17.5" x 21.4" print from 6x7. At this size the print quality will be equal and probably starts to fall short of excellent. None of those prints are a linear increment of 70% larger than the previous print size.</p>

<p>5) If we enlarge the 6x7 negative sufficiently to fill the long side of the 10x8 print, the quality factor between it and 645 falls to (4.57/3.57) = 1.28 times.</p>

<p>QED.</p>

[iangillett]

<p>Barry - I apologise for not replying sooner. I thought I had sent a reply but could not then see it in this exchange. I use an Epson Perfection V750 Pro scanner. i am pleased with the results I get from this scanner (I use it for 35mm, 120 and 4x5) although I do not use the scanned files for printing - to be fair I haven't tried to. The images look good on my computer screen and TV.<br>

Best Wishes</p>