will_frost

<p>Ah! Thank you Gene, that's exceptionally helpful! I'll start digging up a copy of that right away.<br>

Will</p>

<p>John,<br>

Right, 8x10 is a kind of worst case scenario, because the "natural" viewing distance where the image fills your field of view is the same as the "close" viewing distance of about 15-18". However, I've noticed that no matter how big you print, after people have gotten a good look at a normal distance, they always walk up to the distance that resolves the finest detail.<br>

The main thing I'm interested in is getting a handle on how blur effects work - how they add together, and how they can limit what I can get done.</p>

<p>Thanks Dave,<br>

Ah, then if I'm doubling it for print magnification, then if I double the number of megapixels, that would count too, right? Or if I double the area of the sensor?<br>

E.g.: 10 megapixels - > 20 megapixels<br>

or:<br>

4/3rds format - > full frame<br>

Both of those cases are like doubling the magnification, right?<br>

Will</p>

<p>Hi all,<br>

Given that you should use 1/focal length for hand-held shutter speed, should you double it when you double your print size?<br>

In other words: if I'm using 1/50th of a second on a 50mm lens, and printing at 4x5, should I be using 1/100th of a second at 8x10, and 1/200th at 16x20? Or once you get beyond 1/100th with good grip technique, does the blur from being hand-held get swamped by all the other factors that introduce blur? (Depth of field/focus errors/grain or noise, etc.)<br>

Thanks everybody,<br>

Will</p>

<p>Wow.<br>

What an incredible response to my question. Thank you all very, very much. This has been very enlightening.<br>

<strong>Dave Redmann,</strong><br>

I understand what you are saying about the 6x enlargement factor, and I see that you are saying that that rule of thumb works for prints viewed at close (maybe 15-18"?) distances, not the distances people stand to view the whole picture. An 8x10 is probably the hardest print size in terms of people's standards for sharpness, then, isn't it? People would have high expectations for something best viewed at less than arm's length.<br>

<strong>Gene Aker,</strong><br>

I had done some DOF calculations and I know it's pretty tough when you get to 4x5 at wide apertures. I had been thinking of starting with the 127mm Ektar, because it gives me a little extra to work with. I think it worked out to be 1'3"of depth at a subject distance of 8 feet, at f/5.6. Field of view is about 6 ft wide × 7' 6" high. f/5.6 works out to be EV 8, I think, assuming 1/60th of a second and film rated at 800. EV8 is pretty bright by my standards, so I know I'm right at the ragged edge of this being at all a successful approach. (Without adding quite a bit more light!)<br>

I'm actually accustomed to using the equivalent focal length and subject distance in digital for full length/environmental portraits because it allows me to get physically closer to my subjects and relate to them more naturally. Standing off at a distance with the Yashica is a much different experience for me. I would consider 90mm, but I understand that such lenses are quite expensive and that the rear elements often don't clear the bellows on press cameras. I should probably be thinking about tripod mounting the camera, and sitting or standing closer to the subject with a remote release anyway, if I'm going to be using LF.<br>

I had considered doing a series of truly huge enlargements, life-sized prints of these full length portraits, but I have some serious doubts about my ability to handle the logistics of the project. I believe that would work out to be a 16x enlargement of around 64"x 80" (or 5'4"x 6' 8" ). It would be interesting to see how closely people would be willing to approach the prints in a gallery setting.<br>

<strong>Michael Axel,</strong><br>

Thanks for that tidbit - that helps!<br>

<strong>Dan South,</strong><br>

I hadn't considered wind, but the surface area of those bellows is pretty large, isn't it?<br>

<strong>Kelly Flannigan,</strong><br>

Thanks for the detailed answer. If I'm doing full length portraits, I'll have to watch what I'm doing quite carefully so that the sitter's head stays inside the central area of sharpness with these kinds of lenses. Goes against everything I ever learned about composition and using the full frame, but now I understand the tradeoff. I had wondered why photo processors had settled on 4x6's for prints - that covers a multitude of focus errors, doesn't it? That is quite a setup you have there - color me impressed.</p>

<p>Kelly Flanigan,<br>

Let me echo back to you what I understand:<br>

What you are saying is that the Ektar 127's Tessar type lens is likely to perform very much like the Yashica's Tessar type lens, and that most of the difference that I will see between the two cameras is going to come from the enlargement factor. You are saying that the Ektar lens is close to it's limit for contributing additional resolution when printing at 16x20. (And it is close to it's limit because it's designed for center sharpness, so a Tessar design that would put high resolution at the corners would need to double the image circle.)<br>

I also gather that the enlargement factor mostly contributes to the smoothness of the image? Less visible grain, and therefore really seamless transitions between shades of gray? I hate to sound stupid, but I really want to understand this clearly.</p>

<p>Thank you everybody, that was very helpful! 16x20 seems to be the consensus, with one vote for contact printing. (Which I think is a pretty neat technique. Maybe I'll get an 8x10 camera someday just to do that.)<br>

Michael Axel, I'm curious - did he mention that it wasn't practical due to camera motion blur, or just because the camera gets annoyingly heavy and hard to position after a while?<br>

Special thanks to Rafal Lukawiecki for mentioning what kinds of lenses and formats he has experience with. That kind of detail gives me confidence.</p>

<p> At what print size is the difference between medium format (6x6 cropped to 6x4.5cm in my case) and 4x5 really noticeable? Not "I can detect a difference" but "wow, that's much better." <br /><br />I ask, because I am thinking of getting a 4x5 Speed Graphic to use along with my Yashica TLR. Neither has a particularly modern lens, the Yashica D has a Tessar-type Yashinon 80 f/3.5 , and the Graphic is most likely going to have an 127 Ektar or 135 Optar. I do full-length environmental portraits (with some bounce flash) close to wide open (around f/4-f/5.6) on Ektar 100 (when the light is good) and Tmax 400, rated at 800 (the rest of the time). I also do a handful of landscapes, most of which have a close focus point of no more than 25 feet, usually closer to 150. I am likely to use faster color film, most likely Portra 400 in the Graphic if I can get away with it. <br /><br />I typically work handheld, and I also have my film scanned, but not drum scanned.<br /><br />Thanks all,<br />Will</p>

<p>John Tonai,<br>

Does it actually help?<br>

Will</p>

<p>I know this topic has been done and done and done, but I want to say thanks to everyone who's tackling it again, since digital keeps changing. (So does film, but a bit more slowly.)<br>

I am on the cusp of abandoning MF for the expense of scanning and postage. (Development and film costs are kind of reasonable, if I don't do too many rolls a year.) Most of the reason I am using MF is for cases where the dynamic range is hard to nail down with digital or when the environment is too harsh to risk an expensive camera.* The other reason, of course, is sentiment.<br>

I did do some calculations for how many frames I could shoot a year for the price of a Sony A-850, which I am guessing is approximately on par with 6x6 MF.** It ended up that if I shot one frame per day, per year, I could buy an A-850 in four years. Price includes shipping & scanning, but not drum scans or prints. (1 shot/day/year=$497.92, 12 shots/day=4380 frames, for $5,975.05) Mind you, my estimates really aren't good to the penny, and probably not even to the tens place.<br>

Of all the things I find limiting about MF, I have to say it's not the fixed focal length of this particular TLR, (normal lenses are fun!) but it is the shallow depth of field at wide apertures. And by wide, I mean f/3.5, an aperture I am accustomed to thinking of as dreadfully slow on my DSLR. I often find myself in a corner where I can either dramatically underexpose or lose focus. Then having too little dynamic range doesn't seem so bad.<br>

*Dropping a Yashica in the sea is sad, but is still 10x cheaper than dropping my DSLR in the sea.<br>

**Particularly since the 6x6 frame is often cropped to 6x4.5</p>

<p>Just out of curiosity, are there test charts for "medium contrast resolution"? Something like 18% grey bars on a white background and a black background? That would be a helpful standard, wouldn't it, since you'd be pretty much guaranteed to run into that sort of contrast in the real world most of the time?</p>

<p>Marco Boeringa,<br>

I found your comparison test for Ektar vs. Velvia vs. Portra vs. the A900 quite useful.<br>

J Marrs,<br>

In that test, I see a control (the flatbed scan), and four experimental groups. I think Marco Boeringa demonstrated a distinct difference in apparent resolution between the groups, and a distinct difference in apparent noise between groups. I encourage you to repeat the experiment, or to design and conduct a better one.<br>

Everyone else,<br>

If anyone reading this thread is interested, the test is located <a href="http://www.boeringa.demon.nl/menu_technic_ektar100.htm">here.</a><br>

Will</p>

<p>Mauro Franic,<br>

You begin by saying "This post is not a competition with digital, it is a discussion on Velvia dye clouds."<br>

You then compare film to digital: e.g.: "A lot less resolution than just MF film and at a joke of a price."</p>

 

<p>Thanks everyone, that was helpful and informative!<br>

Ingemar, the note about the thickness of the base versus other films was a neat detail.<br>

Will</p>

<p>Hi all,<br>

I'd like to know when you choose to use Tmax-100 instead of Tmax-400. What circumstances, and what subjects would make you choose one over the other?<br>

Why do I ask? I'm currently using Tmax-400 almost exclusively, mainly out of habit.<br>

I'm using it as a low grain, wide latitude film in medium format, rating it at 400 and 800, and sending it out for developing without pushing. (Basically what the spec sheet says to do.) The film is scanned, and contrast is tweaked in Photoshop. I chose it out of familiarity - I learned on the previous version, Tmy, in college, and a hunch that the fine grain makes for better scanning.<br>

Thanks,<br>

Will</p>

 

<p>I heard back from Dwayne's. They confirmed that they send back spools on request, but didn't offer to sell me any.</p>

<p>That's a good point, Asim. I'll try them next<br>

Will</p>

<p>Thanks for the reply, that was helpful. I decided to contact Dwayne's, too. We'll see what happens!<br>

(Fingers crossed!)<br>

Will</p>

<p>Can anyone recommend a source for 127 film spools, or 620 spools?*<br>

I'm intent on cutting down some 120 for my 127 camera and re-spooling 120 on 620, but so far the great google is only showing me sources for new film, or expired film and Kodak brownies on that auction site. Maybe you know a commercial processor that handles 127 & 620 that would sell me a bunch?<br>

Thanks all,<br>

Will</p>

 

<p>I've taken apart a Nikon E-series 50mm 1.8 for a similar project. Not hard, but you do need to break a plastic retaining ring to remove one of the elements. Be very careful with the removing and replacing the aperture assembly in the process - once out of the lens it is very delicate.<br>

<br />I picked up the lens from KEH, as a UG, inoperative lens. (Mold etching on the front element). Most Nikon lenses of that vintage had 52mm filters, I believe (check!). If you want a bunch of cheap 52mm spacers, buy a stack of 10 used skylight/UV filters from KEH, and break the glass out one at a time, until you have the length you desire.</p>

<p>Thank you Edward, David, Tim, D Purdy, and Tim. You have given me a lot to think about. I'll think about all this overnight, and put together a more sensible reply. (And if anyone else wants to chime in, I'll be following this thread closely.)<br>

Thanks again,<br>

Will</p>

<p>I enjoy doing full-length environmental portraits, using a 28mm-equivalent lens - mainly because I like being physically close to my subject, making eye contact, etc, when I work. I understand MF doesn't have many inexpensive wide-ish options. Do you all have suggestions?<br /> <br /> I've heard about 6x7 and 6x9 folders, Koni-Omega's, and Kowa's. If you have used these cameras, can you tell me more about them?<br /> Are there other options that I should consider? Should I try a roll-film back on a 4x5 or smaller press camera? I have to work handheld most of the time, so I'm concerned about how much weight I'll have to deal with.<br /> <br /> I also enjoy using that same angle of view for landscapes, though any wider-than-normal angle of view would probably be fine. I don't mind converging verticals, but I am often limited in how much I can back away from from trees when I work with a normal lens (f=85mm) on a 6x6 folder. Lying on the ground trying to peer into a rangefinder window to get the framing right is really uncomfortable. <br /> <br /> Would a TLR (f=80mm) might work for this, since I could basically place it at my feet and angle it upwards. Do you think that would work?<br>

Will Frost</p>