The Proof

Since I was asked, here is a sample of one of the proof sheets I've been making using XnView. The original is 3075×2175 pixels, for printing at 300dpi. This is enough to see detail on the page. For a 100% detail showing the level of detail that's visible, just click-through on the image at right.

This week marks the last one of the SFMOMA show, Diane Arbus Revelations. We've been there twice now. I'm tempted to return.

Some of the surprising things in the exhibit (which may be in the expensive companion book) are a few of Arbus's proof sheets. Some are about what you might expect: a suite of similar shots from which just one was selected. But for most of the others, what's astonishing is their variety — proofs where each photo is markedly different, of a completely different person, sometimes in another location. The photos that were printed weren't one from a set — they were just the one photo.

I know that Arbus was constantly dismissive of her ability to know what was in the photo until she saw it. But the proof sheets tell a different story. In, nail it, and go on to the next thing. Pretty impressive. Scary, even.

Posted January 30, 2004 | Comments (2)

Fixer Fingers

Three rolls of Tri-X, X-tol 1+1 for 9 minutes.

Amazingly, I still have a film backlog from November — the three rolls now hanging are from a trip to Speaker's Corner and a following visit to Copenhagen. Glancing at the negs it seems clear to me that I still have quite a ways to go with the DSLR before I'm as comfortable using it as I've grown to be with the Contax.

I've decided my next system expansion will be to hybridize slightly — to take the advice of Sean Reid and, for about the price of the Canon 28mm ƒ/1.8, get the Contax 28mm ƒ/2.8 and an EOS adapter (Better sell the rest of that older Canon gear, huh).

There's just comething about the Zeiss lenses, whether its the design or the coating I'm unsure, but it's there — I could see it just glancing at the first roll of negs when I bought my Contax. They were visibly different from Canon negs, even before they were printed. Sharp? Snappy? Sure. But it's more than the photodo measurements, even as high as those are. Even Canon's own lens designers have said it: "Sometimes what the eye perceives is slightly different from what is expected, even if all the measurements meet the proper values. We've experienced the fact that the perceptions of an expert surpass the precision of measuring instruments."

Posted January 29, 2004 | Comments (0)

Stirring up the Pot

Right on the heels of my previous post about DSLR circles of confusion and sensor size, Canon goes and releases (well, leaked) news of the 1D Mk II, with an 8MP sensor and a new multiplier factor: 1.3× — my guess got the exact sensor size wrong, but the trend (and apparently price) just about nailed.

So much for Canon going the EF-S or Four-Thirds route — they're clearly headed in the direction of full frame for the line.

This will play a bit of extra havok with the lens market, which can only sell more lenses for Canon (and a few for Sigma and friends). That 50mm is now a 65mm, getting right into Leica R "normal" territory. And the 20mm is genuinely a wide lens again. I wonder how many 16-35 and 17-40 zooms will pop up on Ebay later this year.

Posted January 28, 2004 | Comments (0)

The Certainty of Risk from Power Tools

I've enjoyed Michael Johnston's Sunday Morning columns for the past couple of years — back in 2002 he published a short list of book titles that he considered crucial for "practicing photographers." Some I had read, and others I logged-away in my PDA for future reference. I generally trust Michael's opinions on photography as being reasoned and informed, even if they don't always coincide with my own (He also was the one who, through this article, got me going on a chain of links to John Brownlow and the streetphoto list).

In the past couple of weeks I unearthed that list again, and reserved the titles I hadn't read through the San Jose State University Library. this morning I also discovered that Michael had posted an Amazon "Listmania" version of the very same list, along with a couple of bonus titles.

What I like about his list is that with one exception, it's not about cameras. With one exception, it's not about film. And in several cases, not directly about photography at all. And in one case (Robert Adams's Beauty in Photography), I'm not even sure the photo book isn't really about something else.

The book that has struck me as most broadly-useful to the day-to-day world beyond photography is David Pye's The Nature and Art of Workmanship, a title that, as the link illustrates, has far more applicability that its original nominal topic of woodworking. I'm surprised this book isn't better-known.

It's ironic that within pockets of resistance to digital photography and printing, such as APUG, one of the shared myths is the notion that digital photography replaces craft with computer software. Pye's woodworker's perspectives, published in 1968, can function as a powerful broom on such mental cobwebs.

Posted January 27, 2004 | Comments (0)

So Much Confusion

(This entry has nothing to do with John Matturi.)

As a followup to the lens hack of a few days ago, for laughs I thought I'd poke the Canon sensor into David Eubank's PCam as a custom film format, to give myself some extra guidance on demand about technical details like Depth of Field. 22.7mm×15.1 mm, 3072×2048 pixels... so what should I choose as a Circle of Confusion size?

For 35mm, typically the CoC value is around 20-25 microns (0.02-0.025mm). Chances are that Canon (like most lens makers, save Contax and Leica, which are stricter) uses 25µ to calculate the Depth of Field markings on EOS lenses. CoC is a rather slippery number, based on subjective evaluations of 8×10 prints viewd from two or three feet away, which is why lens DoF markings for medium format cameras use a much larger CoC value — typically around 50µ — which is proportional to the larger negative size (which will in turn be enlarged less when printed to 8×10. In signal-processing terms, they are trading some spatial frequency for dynamic range, which is why MF prints have their characteristic "richness" in comparison to a same-size print from 35mm).

So for a sensor that's 1.6× smaller, the CoC should be... around 15-16µ (Zeiss formula give 15.75µ). And the DoF markings on EOS lenses should be closer-together, too. But can the sensor get to that precision? And what about the change in field-of-view for smaller sensors? Don't small sensors give you greater DoF?

The pixels in the sensor are around 7.4µ, so that CoC value is essentially above the Nyquist limit for a sensor of this size. As long as you're printing to 8×10, there's really little point to making a sensor with more pixels at this sensor size, unless you intend to combine them for greater color depth (the color depth in a chip like Canon's is already a bit eroded due to the color-making pattern used to extract color images from a B&W sensor).

(Few users, without a very solid tripod, will get anywhere near this limit anyway, even with the best lenses. External factors (see photo) are always getting in the way....)

Further, it means all of the DoF marks on EOS lenses are wrong for this sensor (and by extension, to other cameras with similar sensors that use 35mm SLR lenses, like the 10D, 1D, Nikon 100D, Fuji, Sigma, Pentax *istD, etc) — the marks are all too wide.

But what about smaller sensors having greater depth of field, a fact so often trumpeted byt the makers of pocket digicams?

For the same field of view, the focal length will be shorter. So compare, for Canon's 6.3MB sensor, the 28mm lens, versus a 45mm lens for a full-frame (36×24mm) sensor (same field of view). The pixels on the small sensor need to be smaller, forcing a smaller CoC, but the distance to the subject — proportional to the focal length — is greater. The effect of that subject distance proportion trumps the CoC concerns, so compact digicams have greater DoF. This means that the 28mm lens on a 10D will have more DoF than a 45mm lens on a full-frame camera, but it doesn't change the fact that with a 50mm lens, the digital sensor will have less DoF (and a narrower field of view) than a full-frame camera at 50mm.

Circles around circles. So where do we go from here?

There are a few ways to go on this. One, taken by Olympus on the four-thirds system, is to just toss-away the old big-sized lenses, build lenses for the new format, and get on with things. Nikon could potentially follow suit, since they've said they like the smaller sensor too. So will Nikon start relabelling their lenses, or just ones specifically made for use with smaller digital SLRs, or just live with the erroneous DoF markers, or start making four-thirds lenses?

Canon (and Contax and Kodak), in the meantime, has started making full-frame digital SLRs. They've made one digi-specific SLR lens, the 18-55 EF-S. It's rumoured that they don't intend on making any others. It has no DoF markers. There's a prominent gap in the Canon lens lineup — no rectilinear primes between 20mm and 14mm, which is exactly the length you'd want if you were trying to use a full-frame 24mm/28mm view angle on a small-sensor camera like the 300D. There are some zoom lenses in that range, but they're huge, heavy, expensive, slow, less sharp than a prime, and of course the DoF markers are wrong.

My hunch — Canon will be pushing full-frame cameras down into the lower tiers of the DSLR line. My guess is a camera between the 10D and 1D, with a full-frame sensor, in the $3000 range, late this year.

Posted January 24, 2004 | Comments (1)

A Corker

So if you live in NYC, as I used to, you know what WFMU is, and you probably know that they have an interview program called The SpeakEasy, and you might even know that the hostess Dorian has a habit of bringing photographers on the air to talk, without pictures, about pictures.

Recent guests have included Steve McCurry, Mary Ellen Mark, Jerff Meremelstein, Jonathan Torgnovik, Peter Howe, and Philip-Lorca di Corcia, so very recently distantly parodied on this very site.

Di Corcia's interview is in the true photrant tradition — "Cindy Sherman... fruit flies have evolved more than her work" is just the tip of the iceberg. A worthy waste of an hour of your time.

Posted January 23, 2004 | Comments (1)

Hacking the EOS

As I mentioned before, I like the feel of an 85mm ƒ/1.8 on my 35mm SLRs. On the Canon D300, the 50mm ƒ/1.8, with the 1.6× multiplier in effect, is almost the same lens — an equivalent to an 80mm for the 35mm camera.

An awkward feature of that particular Canon EOS lens is its complete lack of distance scales. The 50mm ƒ/1.4 has them, but at a much, much higher cost. So I just wrote some on the side of my lens.

First I marked one of the knurled edges on the focus ring with an office white-out marker (model paint might have been better, but I didn't feel like digging that stuff out of the garage). Then I cut a scrap of cloth first-aid tape (which I also use for framing and matting) to the right length, with a notch for the MF/AF switch. Finally, I did some quick measurements in my kitchen, focused to the appropriate spots, and made marks on the tape with a ball-point pen for infinity, 10, 5, 2.5, and 1.5 feet. Close enough for wandering around shooting from the hip.

Total upgrade time: less than ten minutes. I'll happily sell this lens for $200, now that it has the cool ƒ/1.4 feature. That's cheap compared to Canon's price!

One thing that's missing is depth-of-field indicators. By my estimation, ƒ/22 markers would be quite close together — about three notches, or a little bit less on each side than the distance between the infinity and 10-foot marks.

(PS: This later entry gives more detail on DoF for digital cameras. I realized I was slightly wrong — the markers would need to be closer-together)

Posted January 22, 2004 | Comments (2)

Filing Systems: The Virus

So during the South Bay Bloggers' Meetup on Tuesday Night, I discovered a new sport: Google Voyeur.

Simplicity itself: take a typical digital-camera photo ID, like the one on my previous entry. Title: 143_4354

Now, just poke that number into Google. Chances are, it'll come up with other people's digital photos. Their personal photos, dutifully crawled and catalogued by Google's robot.

Posted January 21, 2004 | Comments (0)

143_4354

Posted January 09, 2004 | Comments (1)

Size Matters

By far the biggest xmas surprise was also in the biggest box — so big Courtney had to hide it in her car's trunk. A new printer to replace my small and aging Epson — a new Epson 2200, which can print to a much larger size than the 870. And timed perfectly to arrive even as I was informed of the latest Harrington Quad Tone RIP for printing a range of warm or cool-toned images from B&W photography. Not with a special inkset, like Piezography or the MIS inks, but using Epson's standard archival Ultrachrome inks.

After a bit of fiddling to install Ghostscript and GimpPrint into Mac OSX, I was ready to print. First image to roll out of the new printer — fantastic. A beautiful tone, no obvious metamerism, surpassing anything I'd been able to get from the 870 despite months of careful personalized profiling. A little weak in the darkest tones... quickly corrected by replacing the "Photo Black" ink with "Matte Black" for printing on Epson Enhanced Matte Paper.

Holding a print in your hand is far different from ogling a transient colored rectangle over the web. As my buddy Roy said: "We're not computers... we're physical."

For this same reason, I've been busy for the past many days building "contact sheets" from all my scans and digital-camera images, using XnView (which lets me add more data per-image, yet with less wasted space than Photoshop).

I usually build a small index image for each roll or session anyway, but this time I'm building 3K × 2K, not for on-screen viewing but for printing @ 300dpi commercially. Not on the 2200 either, though it would be tempting — the sheer quantity rules it out, as I've built around 1000 contact sheets so far. Courtney's been kind bulk-feeding them at a bulk-printing rate through her work, a few dozens or hundreds per day.

The result is sheets that I can hold and browse by hand, with far greater ease and detail than what I could get from the computer — even using a browser like Extensis Portfolio. My goal isn't to rapidly find pictures by subject or keyword, but to drink them in, to wash in a torrent or sip slowly. Always ready, no disks to load, viewable anywhere without a monitor, trivially transportable, and detailed enough to go back and track down the original file, scan, or negative as needed.

Personal contemplation defies keyword classifications, you need paper for this sort of thing.

Meanwhile, the 2200 — Sadly, no one local carries Hahnemule Photo Rag paper, which should be best at providing the deepest, most luscious blacks from the 2200. I'm left to wait for an online order. I'm eager to compare it to my beloved Crane Museo, which performed so well with the 870.

Posted January 02, 2004 | Comments (2)

Coughing Up Blood

No, I'm not dead yet! Just a little messy.

Sorry for the interuption in service for the past several days, and the lack of new content for many days. Botzilla's now on an all-new server for 2004, even as the old server slowly melts into a puddle of slag.

Not eveything is functional just yet — I'd appreciate any problem reports.

Posted January 01, 2004 | Comments (0)

 

All content on botzilla.com is 1994-2017 by Kevin Bjorke. All Rights Reserved.