Sepia Blues

Almost two years ago I wrote an entry about in-camera sepia, wondering if in fact a sepia transofrmation could provide a photo with more tonalities than a tyical 8-bit black and white.

At the time, I assumed that the crucial yes or no part of that answer would involve the B&W conversion -- if it was done before the sepia rotation of the color space, or after -- that is, if the # of B&W values was fixed to 256 and then rotated, or if it was in a higher precision RAW format, rotated, and then quantized to eight bit. In the latter case, you'd have more tones.

I was half right, and it was the poor half. Looking closely at LX2 sepia images like the one above, it's become clear that the B&W is converted and quantized first. And the part I was wrong about I didn't expect -- that the LX2 creates sepia images not through a matrix transform in RGB color space, but simply by adding a color to the B&W image. The color appears to be (+30R,-18G,-38B). That is, raise red, and drop green and blue, by a simple addition.

Since the values are already clipped to 8-bit, this means a loss of highlights in the red channel and a loss of shadow detail for green and blue. Since all three are made from the same B&W original, it's possible to rebuild that original B&W 8-bit picture by adding (-30R,+18G,+38B) and then selectively using the shadow detail from the red channel and the highlights from the green or blue channels. The result, in Photoshop, is the same as if the pic had just been shot in B&W to start with (barring JPEG artifacts).

So why does it seem to have more tonality? I'm guessing that it simply looks better on the small, contrasty camera LCD.

It's a tragedy that the B&W image is already clipped to 8-bit before sepia conversion. If the image was unclipped, the sepia conversion realy would be better, with and increased number of shadow tones in red and highlights in blue and green. It is what it is, though.

At least for web use, this is suggesting to me the following work approach for high quality B&W from JPEGs (when time demands preclude shooting in RAW):

• count on spatial resolution as a stand-in for pixel depth detail. Given some level of pixel noise, 4x4 8-bit pixels should be better than one 12-bit pixel. For a reduction from a 4K image down to a 500-pixel web snap, there are a lot of input pixels for every final output pixel.

• with this in mind, set the camera to a low-contrast image, to compact as much of the original RAW range into the 8-bit jpeg, and then feel free to beat on it using levels and curves later on -- knowing that even if precision is lost per-pixel, a lot of it will be made up in the size reduction step.

I'll report on some results soon.

LX2 Part 2

As I expected, I've gotten more used to the LX2.

In the clichéd and time-honored tradition of pointing Leicas at brick walls to prove that their lenses are top-notch, here's a closer sample of an in-camera-sepia JPEG. The right-hand area shows a detail from the picture on the left -- pixels at one-to-one size (if anything, the image here is degraded just because it's a web-compressed pic. It was also hand-held).

As long as I'm willing to put my thumb on the monitor, it's fine in the hand. During the past week I've been shooting with it at the ION Conference, using it as a notepad to keep track of presentation slides. In the hand for an hour at a time and I've gotten used to the idea. No hand strain. In JPEG, it's also plenty fast.

Tomorrow I'm taking Gary's advice and trying a much faster SD card for shooting in RAW mode. If it can get the differentials indicated on Rob Galbraith's benchmark site, there might be as much as a 4x acceleration, which will keep me quite happy (even a modest improvement might be enough).

LX2

After returning from China I gave myself a few weeks to see if Panasonic would announce a new LX3 at February's camera-business trade show. No dice, so I promptly ordered a new LX2 to replace the stolen LX1. Here are a few notes, comparing the two.

Only the LX1 camera, one card & one battery were pickpocketed -- my case & charger, 2nd battery & backup card were still in my luggage. Not surprisingly, everything fits perfectly, equipment-wise. Perhaps with time I'll also learn to adjust as smoothly.

The lens is the same killer Leica 28-105-ish. I have been impressed with the improved color renditions, and I don't mind the slightly different character of the in-camera JPEGs (I also don't buy the notion, proposed by some bloggers and others on photo.net, that the LX2's "Venus III" chip does pre-processing on its RAW data -- an assertion that makes no sense to me).

The higher ISOs (two extra stops, from 400 to 1600 as the top end) are a very welcome addition, regardless of how noisy the highest ones may be. A sharp grainy photo is better than an unreadable blur or no photo at all.

I might yet tape the back of the camera for grip as I did the LX1 -- but not the front. The LX2's front finger grip is much-improved in providing your middle finger purchase. Simple, and well-done -- but it needs to counter a downside change, hands-wise: to accommodate the larger LCD screen, the LX2's designers have cramped the rear-side controls. It's harder to shift your (my) thumb around and hit the correct thing in that smaller space.

If I want to hold the camera firmly, one-handed, I end up with my thumb on the screen (and away from the buttons). I am pretty sure that I only rarely used the LX1 one-handed, so this difference may feel like a bigger deal than it is.

Overall, the narrower thumb space means that my hand is significantly less comfortable when holding the camera "at rest," and that in turn creates the (false) impression that the LX2 is heavier.

The controls themselves have been subtly improved, mainly by Panasonic's UI designers realizing that people confuse the joystick with the directional buttons -- so, whenever sensible, you can use either control to accomplish the same task. This is good usability design, thinking about what the user wants to accomplish and letting them get there in the way most natural for them. A+

The biggest impression of difference between the LX1 and LX2, however, has been speed of operation -- or rather, the lack of it. The LX2 is slower between shots. I would have guessed about 25% slower, which matches change in the pixel count. dpreview's test shows a 32% slowdown on RAW writes, as well as a slowdown in burst mode. Those percentages feel like a lot, given the rhythm I'd already developed with the LX1. This is frustrating given that the camera's operations are otherwise responsive and the AF is even a tiny bit quicker. That extra second and a half of write time can be tough.

Token LX1 sighting: I saw Sylvia Plachy using one on Ovation's televison bio Close Up. She was switching back and forth during the same session between an LX1, a Leica M, a Rolleiflex, and a Hasselblad 500 of some sort (SWC?).

Long Ride

Almost time to say goodbye to China, now that I'm back in Beijing. Also time to say goodbye to:

• My Canon 50mm f/1.4, which spontaneously has decided it doesn't want to focus on anything closer than 5 feet, even in manual (at least until I can send it off to Canon)
• My Panasonic LX1, which was pick-pocketed in Xi'an (along with most of my pix of the Xi'an city walls and street musicians)
• My HTC Excalibur smartphone, with all my notes and action items from the entire trip (pick-pocketed just tonight inside the Hyatt)
• My faith in Cisco VPN (pretty-well worthless on this trip)

So that's maybe $1000 in theft losses and a major dose of work frustration. Net balance for the trip then? Love it. Hassles and troubles like those just transform a vacation into an adventure, and the experiences I've had will last a lifetime, unlike any sort of electronic gizmo (and I have paper backups of my notes).

If I can just keep my laptop and 5D working for two more days....

(Followup: I remind myself, a bit, of my old second (third) cousin who raced motorcycles and cars and kept soldiering on through the many hospitalizations as just part of the passion....)

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Which doesn't begin to compare to what happened to Michael :(

What I Learned on My Summer Vacation

• There is nothing to deter you from making lots of photographs with your full heavy kit bag like an intense peeling sunburn across your shoulders and back.
• Spending time with your son being hurled down the "Pacific Spin" at the water park while being seriously sunburned across your shoulders and back is 100% worth the trouble.
• I thought I knew a lot about the California landscape, having driven through it and flown over it at varying altitudes countless times. Then I took the train from San Jose to San Diego.
• At night, it is better to fly.
• In Los Angeles, yes there really are people dumb enough to drive their boyfriend's new car in between the rail-crossing barriers, panic when they see the 9:20 commuter coming toward them, decide to drive away in the opposite direction on the railroad tracks at high speed while calling said boyfriend on the celphone -- until the damage to the auto suspension halts the car between streets, paralyzing all north/south rail traffic for an hour or two until an offroad-capable truck can come to haul away the car and an inspector ensure that she didn't do any serious damage, which the police and boyfriend search for her since she fled the scene, in a less-than-optimal neighborhood, on foot.
• Buildings are strongly directional, even ones I wouldn't have expected. They all face the street. None of them face the tracks (even train stations).
• My beard grows much faster than I realized.
• The Chevy HHR has the worst driver visibility I've ever experienced. How do they get DOT approval on this thing?
• Just as it's difficult to go photographing on the street while in the company of someone who wants to hold hands, it's difficult to actually see museums while in the company of people who think museums are (a) phenomenal wastes of skateboarding time or (b) great places to meet guys.
• Just the same, seeing the Harry Callahan show at MOPA for the second time was worthwhile. Like so many, he was clearly caught up in how things look when photographed.
• The people who probably created most of the Dead Sea Scrolls were seriously-deranged paranoid religious nutjobs living in a tiny isolated community. In other words, a lot like tiny isolated paranoid religious nutjob communities today, everywhere from Waco to the West Bank.
• When the computer graphics in a brand-new IMAX film are less compelling than those in some games, even the the general audience notices, and are vocal about it in the lobby after the film.
• Deliberately traveling without a computer (the only available choice up until the last decade) makes you paranoid about filling CF cards but otherwise is no big deal and the reduction in travel weight is a real blessing. No real escape from email (the Treo kept that from happening), and a handheld GPS did a good job of filling-in for Google Maps. No online games, no endless web browsing, no blogging, no RSS. And no withdrawl symptoms, as far as I can tell.
• Rebecca couldn't deal. She brought her macBook. I stayed away from it. She sat in a hotel room while we had fun.
• I wish we had a pool.
• There are some really good and unsung artists working at Legoland. I did not expect this at all. Every diorama is packed full of little stories, classic examples of what Ben Lifson (and Hayao Miyazaki) talk about as "specific" character -- and this made from the uniform little pieces of Lego figures.
• Zac Ephron and little kids in cute Einstein outfits are bigger news than Karl Rove.
• It was too long.
• It was too short.

Hi-Fi Lo-Fi

It's common to tell digital photographers: "don't trust the camera LCD as a preview."

Why the heck not? A lot of the time, I happen to like the picture I see on the LCD. So I made myself an Adobe Camera RAW preset that, as best as I could eyeball, would match the tonal range of the LCD on the LX1.

It was a somewhat subjective process, not entirely perfectly scientific, but simple enough. I shot some Kodak grayscale charts, played them back on the camera LCD while simultaneously loading them in Adode Camera Raw, adjusting the corresponding RAW/DNG conversion on my laptop under Photoshop CS3. I could see where the blacks petered-out, and the overall relationships in tones between neighboring patches. So patch 1 was full-on, the grays died out arounf patch 14, the values were a little boosted around patch 5, etc. It made the picture that I liked.

Once I'd made such a preset fro RAW files, I also made a corresponding adjustment curve that would alter camera JPGs to also more-or-less match the results I was getting from ACR. It's easy to make such a curve with a three-layer photoshop file (I like RAW but some situations — particularly very fast repeat shooting — still require JPEG for this little bufferless compact camera).

To make a curve that matches a JPEG to the ACR result: First, open the JPEG. Next, add a Curves layer and close the Curves dialog (we'll come back to it). Now, open the RAW file in another window, Select-all, and paste it on top of the JPEG (which will make a new layer). Set the blend mode of this new layer to "Difference."

Now all you need to do is open that curves layer again and adjust it until the visible differences between mictures are the absolute minimum. If the picture is black, then both the bottom (JPEG) and top (RAW) layers are a match.

The less-than-wonderful surprise I got was: the pictures don't align. At first I thought it was sharpening, but actually they just don't line up. They are two or three pixels misaligned, apparently at a 45-degree angle. In fact it's not even an integer number of pixels — the pic above (a 100% blowup of the previous blog entry) shows the closes I could get, and shifting it in the opposite direction simply moves the various contour-outlines from one side of the face to the other.

The second surprise was that, despite the fact that these curves reduce the tonal range (that is, they step on constrast), the RAW pic holds detail quite a bit better than the JPEG. I'd expected that since the JPEG had more range than my desired pic, I wouldn't make much difference. But it does. The higher fidelity of RAW still matters even on a low-fidelity images.

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As a minor aside, we noticed last night that the LX2 makes a guest appearance in Spiderman 3 — in a scene where a photographer loses his SLR, he wastes no time in dragging an LX2 out of his jacket pocket & just keeps on shooting.... (though I'd never recommend carrying the camera in your pocket with the lens and flash both already extended).

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Kristie Lu Stout hosts a CNN "Summit" Panel, Palo Alto, 2007

LX1: Ongoing Reports

Whaddaya know, the new issue of Consumer Reports has arrived and what do they pick as their favorite compact camera? The LX2, the latest variant of the LX1 (bigger LCD, higher res, higher ISO's, but the same lens, UI, and camera frame).

I couldn't help but get a smile out of their pic, though: what's she looking through?

The weird part is, I was just getting ready to blog about that topic anyway: not Consumer Reports, but viewing with the LX1 (or LX2, or Leica D-Lux2, or D-Lux3).

At this point I pretty-much know what the field of view is (especially given how much hipshooting I've done), just looking around. I can "see" the picture in front of me without any camera, so I've found it's comfortable enough to just pretend there's a viewfinder. No glued-on dots or minifinder, just hold the camera up near where my eye is (without covering the eye, as CR has bizarrely done), and go ahead & shoot. I can see the top of the lens to ensure me it's pointing straight, and a bit of the LCD glow gives me some vague notion about the luminance (which I usually ignore — can't turn it off, alas -- gaffer tape and a bit of black paper to the rescue?).

And then yesterday, I finally got to reading Sean Reid's Review of the D-Lux 3 and he's commenting on the lack of detail in any LCD screen. Second-Opinion co-reviewer Mitch Alland has his own VF/LCD take, where he say his use of the LCD is mostly about gross-scale framing, and that (somehow) he too uses his un-VF'd eye a fair bit (though not, I think, the way I'm showing here).

Sharp Distinctions

I'm something of a believer in half-baked photo tests. If test results aren't obvious except in highly-exacting circumstances, for equipment that's unlikely to be used in exacting circumstances, then: who needs them?

If results can be shown in ad hoc, half-baked test situations, then they're more worth examining. So here's a quick little comparison. I'm not looking at bokeh, or chromatic aberrations, or anything else. Just focus near the center.

I was concerned about some wobble in the focusing elements of my Canon 50mm ƒ/1.4 lens. I figured I should compare it to my corresponding rock-solid Contax-Zeiss 50, that I can mount to the 5D via a "Cantax" adapter. And since I was shooting at ISO 100 anyway, why not do a quick comparison against my compact LX1?

What you see above are pixel-to-pixel crops from the centers of three photos. The white-balance was set to "auto" for all, so the color shifts are not significant.

The results surprised me a bit. These shots are all made around ƒ/4, 1/250th of a second — handheld but leaning against a wall. I made several exposures & these are 'representative.'

The first surprise, to me, was how poorly the Zeiss lens did compared to the Canon. I had expected the opposite. While it's possible that my manual-focus skills aren't up to snuff when compared to the Canon AF (even with the special Canon 'S' manual-focus screen), I did check the entire frame, and found that there were indeed areas where the Zeiss focus was a bit better than here in the center, specifically in the corners. So either way, the Zeiss had less flatness, or maybe it was just less sharp at the center.

Or I can't focus. Either way, since in this case I only care about photographs that I myself will make, the net effect is the same: I get a sharper result with the Canon, at least for the 50mm. And that was a surprise (I'll have to test the 28mm lenses after the holiday).

I also found that the wobble seemed to have no effect on the effectiveness of the Canon lens (still disconcerting, and I may have to send it in. If I tilt the lens forward or back after locking focus, the elements move — and then I do shift focus. I can also feel a distinct "thunk" when the elements slide).

The third surprise was just how well the little compact PanaLeica held up. At ISO's above 100, or in terms of instant-on accessability, the big Canon dominates — but for good light, the LX1 (or LX2, which has the same Leica zoom lens) puts up a real competetive fight! Especially for a pocketable camera that costs one-fifth the Canon price (or even less: since the LX2 came out, I've seen real LX1 deals. I ran into one at Fry's last week, brand new for less than $300).

In-n-Out, US 101

Yesterday was the last of it: oil leak, timing belt, and today the clutch. All fixed. The car hasn't run so smoothly nor moved so surely for a long while.

I was stuck at home, but the restriction gave me focus while I wrote code.

To celebrate my new clutch: a double-double, protein-style.

Stevens Creek

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