Pentax 645N or other medium format options for A0 prints

[steve_johnston9]

<p> I am looking into a system that will be able to develop some A0 zero prints for my company. I haven experience with 35mm film photography but no experience with medium format. I need to cost up the options for my boss.<br>

I would be looking for a system that is as easily to use as possible as I am a newbie to medium format and has autofocus. I am considering the Pentax 645N, as I have some experience with Pentax and it has autofocus.<br>

Is this a good option ? Can you think of other options ? Cost is an issue, while I don’t know my budget as my boss hasn’t agreed it, I have looked on ebay and seen them go for under £500.</p>

[bob_sunley]

<p>Well you are looking at 20x magnification from 645 to A0. You will have noticeable grain. The equiv from 35mm is A2 sized prints.<br>

6x7 format might be better, only 15x magnification to get to A0 prints.</p>

<p>All depends on how much grain is acceptable in the final prints.</p>

<p> </p>

[chrisnielsen]

<p>6x7 won't have autofocus. But you're going to want to tripod mount it (on a decent tripod) anyway, if you want to make big prints, and especially with cameras like the RB67, you're going to want to slow down and take your time, anyway do you really need autofocus?</p>

[stuart_richardson]

<p>Are you thinking color or black and white? I would say you would be fine with 645 and black and white, but if you are doing color (particularly color negative), you might want to look at 6x7. A0 is pretty big, and while you can do it from 645, 6x7 is going to give you some more room to work with. <P>How many prints and how long do you plan do use the camera? You might be better served by renting a medium format digital camera in the 39mp plus range. Since almost no one is making A0 film prints anymore, you are probably better off with direct digital capture. When you add in the cost of scanning the negatives or slides at high enough resolution to print A0, film and processing etc etc...it might be worth your time just to rent MFD. </p>

[dave_redmann]

<p>Just understand that 645 to A0 is more than a 21x enlargement. It may look okay from a distance, but get reasonably close and the grain will be very evident and the fine details will look fairly mushy. Indeed, even with 4x5 (inch) film, A0 is close to a 10x enlargement, which is pushing it if you want it to look good up close.</p>

<p>How many A0 prints is this, and how often will you need to get them? On that budget, I might ask somebody with a 4x5 to shoot them for you. Is buying a camera really the best option? Also, to get the most out of your film, you will need to invest in a high-resolution drum scan. And prints that big are not cheap. Does your £500 limit apply to everything? Because high-end drum scans would run be $40 US each, and a print of about that size would cost at least $30 US--and that's before you mount much less frame it.</p>

 

[janne_moren]

If I were you I'd first ask myself exactly how I was going to get that A0 print done and how much it's allowed to cost. Once you've found a print shop that can do it to your budget, look at what practical resolution you can make use of with that printer and then take it from there.

 

But yes, 6x7 is going to give you a lot more to work with - and the larger negative over 6x4.5 means you'll need less expensive scanning for the same result. You'll certainly need a tripod as well, as any movement is going to degrade your image. Don't get hung up on having autofocus. For reasonably static or slow-moving targets manual focus is quite easy with the large focusing aids you have with 6x7 cameras. If you intend to shoot fast-moving stuff, then you're not going to get really sharp images at that size without a very involved setup (strobe-only lighting to freeze movement for instance), with or without autofocus.

 

I'd look at a Pentax 67 or a Mamiya rather than the smaller format if I were you. I met a photographer working on an exhibition project two years ago. He was doing life-size and larger than life prints (2 meters vertical) of research robots. His tool of choice was a Mamiya 7, but any of the large MF cameras should be able to give you what you need.

[q.g._de_bakker]

<p>6x7 will give you 1.28x more (assuming that the "7" stands for 72 mm. In worst case, it stands for about 68 mm, and then the factor drops to 1.21x).<br />That means an A0 print (1.189 m) made from a 6x4.5 negative will look as bad as a print 1.28x larger, i.e 1.521 m tall (or assuming 'worst case', about 1.439 m).</p>

<p>That certainly is a difference. But not one that could be described as "a lot more", and certainly not one that would "need less expensive scanning".</p>

[q.g._de_bakker]

<p>P.S.</p>

<p>To have something to compare it to: a 'worst case' 6x7 print has to be 3.368 m tall to be as bad as an A0 print made from a 35 mm format negative.</p>

[dave_redmann]

<p>I agree with Q.G. on a couple of points:</p>

<p>(1) Between a 645 and a 6x7, the scan is going to cost about the same. For a print that size, if quality matters, drum scanning is the only way to go. Typically, unless you are scanning something that consumes a lot more space and materails (like 8x10 inch film), you pay for drum scans by the megabyte. So if, say, the output device is 200 ppi and you scan for that full size (i.e., you scan at high enough resolution so that neither you nor the printer's RIP needs to up-interpolate), whether you get a 645 frame scanned at 4243 ppi or a 6x7 frame scanned at 3419 ppi, the respective file sizes would be 371 MB from 645 and 403 MB from 6x7, so unless those are right at some major price break point, the scans will cost about the same. If anything, give that the aspect ratio of 645 (1.35) is closer to A0's (1.41) than 6x7's (1.24) is, the 645 scan will be a little cheaper, because 645 makes more efficient use of the film area.</p>

<p>(2) 6x7 is better than 645, but I would expect the visible differences to be real but not huge. I thought the most common 6x7's were generally about 56x69.5mm, and the most common 645's were about 41.5x56mm, so that's 1.24x more (linear) enlargement. Can you see that? At these sizes, probably yes. Would it strike the average person as significant? I doubt it. So while I would prefer 6x7, I would not get too hung up on 6x7 versus 645. Of course, I would think that 4x5 (inch) is the way to go.</p>