Category Archives: Hardware

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Fighting for dynamic range

Micro Four-Thirds, Photographs

Lightroom 2 to the rescue

Sometimes there’s no alternative but to restore dynamic range using some manipulation at the processing stage. The Panasonic G1’s smallish sensor does not help in the dynamic range department – the Canon 5D’s, almost four times the area, is better in this regard.

The following is a case in point – I exposed for the brick wall, which is in bright sun, knowing the fire truck would be lost in gloom. Exposing for the fire truck would have burned out the wall and foreground.

After round-tripping the image from Lightroom 2 into PS CS2 to correct leaning verticals (Image->Transform) I saved back into Lightroom and used the Brush with AutoMask switched on to outline the garage bay, first hitting Option-O (this toggles mask visibility) to see exactly what I was masking. Then a quick tweak of exposure and an overall increase in red saturation and the picture was finished.

Here’s the ‘before’ and ‘after’ in Lightroom 2:


Shadow recovery – before and after

As the shape I was outlining had straight edges, I reduced the ‘feather’ setting to zero for a hard edged mask.


Fire truck. G1, 31mm.1/200, f/9, ISO 160

When God gives you lemons, make lemonade ….

From light to bulk

Canon 5D, Micro Four-Thirds

Quite a contrast

I took our boy to a show of Russian and Chinese 1950-era aircraft the past weekend and, because detail was the order of the day, took along the 5D and a couple of lenses.

Quite a change from the G1 when it comes to bulk and weight!

The 5D has marginally better shutter and focus response, though unless sports action is your thing, it’s not a significant difference. On the other hand, the 5D is much noisier (the camera, not the images!) and of course weighs several times as much. The 5D’s viewfinder seems positively dim after the G1’s EVF, although it renders colors and dynamic range more realistically outdoors. Indoors, while the G1 may show some noise, it is in a different league. I simply fail to understand why so many commentators have criticized the G1’s EVF for noise in poor light. Which would you prefer? A dim image in a 5D or like camera, or a really bright and easily discerned one in the G1 with a touch of noise? No contest. Maybe these critics should try to take pictures with their charges?


Commie prop. 5D, 200mm ‘L’ at f/3.5, ISO 250

It was an interesting exercise. Simply stated, comparing digital and film eras, the 5D is to medium format what the G1 is to the Leica M. With the 5D grain is not an issue and just about anything you snap will enlarge to a print size of choice. The G1, like 35mm film equipment, needs greater care. If you are going to push the size of your prints and the ISO setting, be prepared for compromises. The difference is likely to be less as time passes and technology marches on. While film peaked in quality years ago, digital is just getting started.

Olympus EP-1 …. woof!

Cameras

A real dog

Coming from David Pogue, the New York Times’s technology writer with a knack for making the technical understandable, is a review of the new Olympus EP-1.



Click the picture for the review

Well, sorry to say, the camera is an awful disappointment, and an expensive one at that. No viewfinder, horribly slow focusing (Panasonic refused to share its superbly fast focus technology from the G1 with Olympus) and, yes, you guessed it, miserable shutter lag. Hard to understand why anyone would waste the development budget on a camera which, while adding interchangeable lenses to a small body, otherwise does absolutely nothing to conquer the three bugbears of compact point-and-shoots.

An LCD screen passing as a ‘viewfinder’, slow focus and shutter lag.

And, at $800, considerably more than the G1 which, for a little more bulk, has none of these problems.

A real dog.

And thank you, Mr. Pogue, for pulling no punches.

Where is the genius of the company that gave us the stunningly original Pen F half frame SLR or the ‘better mousetrap’ of the Olympus OM1 full frame film SLR under designer Maitani?

The G1 kit lens

Micro Four-Thirds

In a word, impressive

I continue to be mightily impressed by the kit lens which comes with the Panasonic G1. At 14-45mm (28-90mm full frame equivalent) it has a most useful range of focal lengths and while the maximum aperture of f/3.5, falling to f/5.6 at the long end, is nothing to write home about, the lens is a fine performer. Back in the days of film, the Leica M street snapper found himself carrying 35, 50 and 90mm lenses for a similar focal length range. Swapping these was no fun, though the offset was that they were 2-3 stops faster in a very compact size. And the lenses were as good, if no better, than the kit lens supplied with the Panny.

Witness this snap taken at the crack of dawn.

G1, kit lens at 37mm, 1/50, f/5.6 iISO at 500

It’s a picture which discloses two things. First, the Electronic Viewfinder in the G1 renders an early dawn scene as if it was bright daylight, making composition incredibly easy, even if it makes pre-visualization of the final picture difficult.

Second, check out the near total absence of halation (light halos around bright objects) in this enlarged view.

Finally, there’s only minor chromatic aberration (red fringing in this case) to speak of in this very high contrast, challenging subject.

That’s no mean performance from an inexpensive zoom loaded with plastic components. It wouldn’t surprise me to learn that many of the ‘glasses’ in the lens are made of plastic. Who cares? It’s the results that count. And this is at full aperture for the 37mm focal length used.

It’s also just visible in this snap that the limiting factor in definition is grain (sensor noise), not lens definition. At 500 ISO things begin to deteriorate as image size grows. The larger image above is consonant with a 30″ x 45″ print, so it’s not like I’m complaining. On the other hand, had this been taken on the Canon 5D, the fine detail, such as the print in the menu on the wall, would have been easily resolved whereas it’s lost in grain here. And, whether you like it or not, if you make big prints viewers will invariably stick their noses in them.

For film aficionados, the ‘grain’ is much finer than that delivered by, say, TriX film. It’s comparable to a medium speed black and white emulsion like FP5 or to Kodachrome 64 in color slide film. So those extolling the wonderful definition of Leica M lenses at f/2 should pause. What use is great definition if your sensor – be it film or silicon – cannot resolve the detail?

All in all – decent sensor, great kit lens – it’s not a bad compromise given how diminutive the G1 is. Absent the usual sharpening on import of the RAW image into Lightroom 2.4 (Amount=100, Radius=1.1), the image is completely unprocessed. And Panny will only improve things, based on their recent rate of progress.

Runner

Micro Four-Thirds, Photographs

iISO does its thing

The iISO function in the Panasonic G1 (“intelligent ISO”), according to the wretched instruction manual which ships with this otherwise fine camera, does the following: “The ISO sensitivity is adjusted according to the movement of the subject and the brightness”. (Page 79). I use this setting in my default setup for street snaps.

Here the CPU in the camera elected 1/500 second to freeze the running boy and an enlarged view in Lightroom confirms that his shirt is, indeed, tack sharp.


Runner. iISO, Panasonic G1

It’s a two edged sword, however. If you want movement blur, it has to be switched off or, much better, simply set the large mechanical mode dial on top to Shutter Priority, in which case iISO is switched off, though that fact is buried in a footnote in the instruction book. As I wrote earlier, Panny must have had some real live photographers involved in the design of this fine camera. Too bad they weren’t involved in the writing of the manual.

A note on AE lock: You can elect whether the ‘AF/AE Lock’ button on the top rear of the body locks focus, exposure or both, much as you can on the Canon 5D, my other ‘serious’ camera (though the G1 is to the 5D as a Ferrari is to a Mack truck). In both bodies I have set the button to lock exposure only, as focus can be locked with a first pressure on the release button of either.

Canon does this right. The AE lock lasts for some 10 seconds – ample time to recompose and take the snap.

The G1 gets it wrong. You have to keep the button depressed to maintain exposure lock until you press the button. That makes for some strange contortions of the hand.

The alternative in the G1 is to enable ‘AF/AE Lock Hold’, a separate choice in the Custom menu, but they got that completely wrong. Yes, it does lock exposure (and/or focus depending how you set ‘AF/AE Lock’) but the camera’s settings remain locked to your exposure even after the shutter is released. You can only unlock things by again depressing the button on the back of the camera. If you opt for a minimal viewfinder display as I do, you don’t know that your exposure is still locked until you notice a super bright or dim screen when making the next picture. You then scramble to unlock things only to find that your subject has gone ….

What Panny should do is change the firmware so that, with ‘AF/AE Lock Hold’ enabled, the lock is released after the exposure is taken. Let’s hope they change this, as selective exposure reading is a useful tool with dynamic range-challenged digital sensors.