28 February 2009
26 February 2009
17 February 2009
Camera: Pentax K20D
Lens: DA 16-45/4
14 February 2009
It has been one of those days.
When everything comes together and you feel content when looking back at it.
The snow that fell last week is still cold and soft as silk. After a spell of temperatures down to -20°C, it has come up to just minus 5 or 6. Add blue skies arriving for the week-end, and you're all set. At least I was. :-)
Today I went cross-country skiing for 20 km (12 mi.), starting from just outside my door. There were, of course, hundreds of people doing the same thing, and it didn't take long to meet friends along the track. Here's one little fellow called Vebjørn who is thoroughly enjoying himself; tobboganning behind mom in what we call a "pulk" in Norwegian. A sort of snow-sleigh for people transport.
In one narrow little valley I came across a place that had accumulated some beautiful growth of frost. It was as if the branches were sprouting elaborate snow crystals. In the shot below, the cylindrical thingy is a birch catkin awaiting spring. Looks like it has to be patient for a while yet.
11 February 2009
The shot above, btw, is made with the DA*300/4; and Pentax K20D. Taken from the same hide as the previously posted goshawk picture. The tight crop is not by choice. I remember wishing for the DA* 60-250/4 right then...
08 February 2009
Half a week ago, fascinated brits watched snow pouring down. I read both enthusiastic and frustrated reports from friends as the weather brought traffic to standstill.
Now, in this country, aka The Frostpit, you could expect that such weather would not precipitate chaos, but it does. We received whatever was left in the clouds yesterday, I think. About 40 cm in my front yard!
Fortunately I didn't have to go anywhere except to the local grocery store. That's just walking distance. And also fortunately, it was Saturday so I had the day off. After clearing the gate from the drifts I took position in my garage and broke a dry spell.
The spell in question is that it's been 3 years since my last decent snow crystal photo. Partly bad luck with the timing of snowfalls and available time for photography, and partly that the required conditions never came together in the last years.
The temperature has to be right; the best interval is between -3°C and -10°C. There can't be too much wind either, because then all the crystals come down all mashed up into fragments. And finally, I have to have time off from work and family to do it.
Last night it all came together. My technique has grown a little rusty since 2006, so for the first hour I got mostly half-melted or broken crystals. Here's one of them. I think it looks quite nice despite being half-melted and broken, and serves well as a token for the situation. :-)
02 February 2009
Rob Galbraith recently published a review of screen quality in four select laptops. One of his conclusions is probably very unwelcome with Apple; their new 15" MacBook Pro comes last in colour accuracy; even beaten by a tiny 10" netbook.
At the top of the heap is a discontinued model from Lenovo; the T60. When this model was current, some manufactureres (not only Lenovo) tried to implement higher-quality panels in their laptops for the sake of more flexible viewing angles. Higher colour accuracy came in the same bargain, but I can't recall it as a feature reaching the marketing hype.
Anyway, the secret behind those screens were a panel type called IPS, as opposed to the cheaper and more prevalent TN. I recommend Wikipedia for reading up on the various panel technologies.
Today, IPS panels are only found in large, high-end desktop monitors such as the ColorEdge series from Eizo. They are no longer produced in laptop sizes. Well... I'm only 95% sure of that, but I have visited the websites of all the major TFT/LCD manufacturers, and the only non TN panel I have found is a 17" wide-screen from LG-Phillips. I suspect that the optional non-glare panel with the coming 17" Macbook Pro is actually this one, but that's not verified anywhere.
As far as I have been able to make out, there are currently no other 17" laptops on the market using this panel.
However, there's more to laptop screens than just panel type. Screen brightness is also important, and so is gamut (the number of colour hues discernible).
Screen brightness is mostly determined by quality and quantity of the light source(s) behind the panel. Traditionally, the backlight is provided by a cold-cathode fluorescent tube (CCFL). In laptops it's most common to use only one tube to conserve power, whilst in desktop screens one can find up to 4 tubes. One problem with CCFL lights, in particular when using just one tube, is to maintain even illumination across the whole screen area. Low-quality screens will often be darker towards the lower half and/or the corners. In Galbraith's test, by the way, there is one CCFL-based screen with two tubes. Even with two tubes, the screen suffers somewhat from low brightness. So I guess there's not much hope for further improvement with this sort of backlighting. At least not without a serious drain on the batteries.
That's where the new LED-based backlighting in eg. Apple's MacBooks or Dell's Precision series comes in. LEDs are superior both in terms of brightness and illumination evenness. It is therefore unfortunate that all the panel manufacturers have put TN panels on top of the LEDs.
I say "unfortunate" with reference to the last of my selected parameters to define a good screen; the width of the gamut. TN-panels are limited to representing red, green and blue hues with 6 bits each (ie. 26 x 26 x 26= 64 x 64 x 64 = 262,144). That's not really a big number of hues between all-black and all-white. IPS-panels, on the other hand, will display 8 bits for each of the primaries, giving you a total of 16,777,216 hues. In theory, at least. In practice the IPS panels don't achieve that wide a gamut, and the Lenovo T60 is a good example of that in Galbraith's test; displaying a considerably smaller gamut than the rivalling TN-panels. However a potentially 64 times bigger gamut than a TN panel will count for something in a good implementation. It's not without reason that the high-end desktop screens still use IPS.
The TN-panels also vary much in the width of the gamut they display in practice. Most of the panel manufacturers give these numbers as a percentage of the NTSC gamut, which is the standard colour space for TV sets. The sRGB is a smaller colour space than NTCS, but I'm not sure how Adobe's RGB relates. The figures stated by the manufacturers vary from a standard around 45% up to, and exceeding, 100%. With hardware supporting only 6-bit representation, I suppose it means that each colour is just "spread out" into a wider colour space. However it may also be the result of what someone in a forum described as "colour dithering". Apparently this is a task performed by the machine's operating system to map the real colour into something viewable on the screen. There was some usual trench-war between Mac and Windows users as to which system provided the best rendering, but I didn't learn much. And stupid as I was, I didn't even bookmark the site. :-(
Well, some technical rant, huh?
The upshot is that it is currently very difficult to purchase a laptop that is both reasonably transportable (ie. smaller that 17" screens) and reasonably well suited for image editing. Despite Galbraith's conclusion that Apple is no longer king of the heap, I would say that the 17" MacBook PRO with non-glare screen looks worth waiting for. It's a bit too big for my taste, but very light for a 17".
I would probably have to run Windows Vista on it, though.
(Grinning, ducking, and running like h...)
Anyway, I will keep looking. My goal is to decide on a laptop before summer. Meanwhile I could simply try to save up some money. As always, quality doesn't come cheap.