Friday, 19 September 2008

The revolution of viewfinders

Maybe a new war has been started by the announcement of the Micro FourThirds system. Some years ago it was unimaginable that a professional or an advanced-amateur digital camera existed without an optical TTL viewfinder. The evolution of displays however forces us to rethink this assumption. In order to do this, let us take a look at the types of electronic viewfinders.

The most compact digital camera has conventional colour LCD in their EVF. In these displays, every pixel consists of three dots: red, green and blue consecutively. It is obvious that the whole display has to contain as many dots as the necessary amount of pixels multiplied by three.

conventional colour LCD basics

LCDs have not got light emission in themselves so back-illumination is necessary to see the image. Cold-cathode light tube or white-LED are usable for illuminate. The mostly used LCDs have no more than 200K dots (300x225 pixels x3) so they can not substitute optical viewfinders.

concept of LCoS display

LCoS (Liquid Cristal on Silicon) is a special kind of LCD. The liquid cristal is placed between metal electrodes and a glass. These electordes reflect the light coming through the liquid crystal. Unlike the previous case, LCoS is illuminated from its front side by LEDs. Due to the polarizing beam splitter (PBS) the LEDs do not have to be placed in front of the display. In colour LCoS the display panel is monochrome, but the color of illumination alternates. If the frequency is high enough, the human eye can not sense this flickering, so all we can see is a still colour image.

schematic diagram of a LED illuminated colour, LCoS based EVF

The main advantage of LCoS display is the high resolution in small size and high pixel fill factor. The image is very sharp and there is no visible pixelizing. The first LCoS' had less contrast than conventional LCDs but modern types have not got this disadvantage.

colour EVF (LCoS) simulation - it is three times faster in reality
(you can stop it in pop-up menu of flash player - right mouse button)

After equivalent focal length and equivalent magnification we have to learn a new abstaction, the equivalent amount of dots. The camera manufacturers never talk about real pixels, only number of dots is represented in data sheets. This is misleading however, because we have to divide this figure by three to get the usable number of pixels. There is no other way for manufactures who use LCoS EVF than representing the resolution of a virtual LCD which has same amount the pixels. In other words, they have to "upscale" their actual number of pixels, because they have no control over the communication strategy of other manufacturers.

Photographers often sceptical about the usability of EVFs, but the fact that the cinematography industry has embraced them shows that their conquest is not questionable. The main problem is that demanding photographers have never met an usable one, because EVFs are built into compact cameras (and into high-end cine cameras, such as the Panavision Genesis, unknown to most photographers). The Panasonic G1 is only a first, but significant step. Its 1.44 MegaDot equivalent (800x600 pixel) LCoS EVF is unusual among digital still cameras, but much higher resolution (>1 MPixel) is also available on the market. Maybe we will meet them in the higher category of Micro FourThirds cameras.

Tuesday, 16 September 2008

Chaos? Bah! Conspiracy!

Both of us are interested in the upcoming micro FT format, but I myself am quite happy with my E-3 (no, you nasty, this is not buyers' remorse - I love this piece of solid chunk), and this is one of the reasons I am sitting calmly at the sidelines these days.


Taken with an Olympus E-3 and a Summilux 25mm f1.4

But hey, this list of contrast-AF compatible lenses got me thinking! Almost all Panasonic/Leica lenses are contrast-AF compatible, including the Summilux f1.4? Only a few Olympus lenses are compatible, excluding the super-fast 12-60mm SWD, for example?

As Jules would say: "Whoa...whoa...whoa...stop right there!" I own both the 14-54 and the Summilux. The latter is not slow, but is it faster than the 14-54? Not at all! So what is it? An extra contact? Let me see... One, two, threee, ... Nine. On both! So? Ok, it was the firmware update! And the 14-54 is old, it's firmware can not be updated! (Hey, but these are all-digital lenses aren't they? With their own CPU, that can be updated at any ti.... STOP! You are interrupting my line of thinking!) But... but why are the new lenses not updated, such as the 12-60, or the 14-35? Wait! These are all SWD lenses and the new technology probably does not lend itself to the continuous movement required by contrast AF! But then why can the 14-54 not receive a new firmware? It surely has an old-fashioned motor, all right. Stop, stop, gotcha! It is the new lenses only with the old type of motor! That is! But then what about the 70-300? New, old motor? It is big! Hard to move lenses do not work well with contrast AF! Ok, so it is the new, small lenses, with old-type of motor that will work. I see. Perfect segmentation of the market: Olympus takes the upper league (SLR, SWD, etc [CIA?]), Panasonic takes the consumers. Hmmm.

OK, this is a feasible theory, but to be honest, we simply don't know. We might be just in the grip of some kind of marketing strategy, but it might be the case that the master of FT will be Panasonic in the end. Are the "macro" and micro Four Thirds formats compatible? They seem to be. Is their combination a sensible way of building a camera system that is solid and up to various professional assignments on the one hand and portable and has great image quality under many circumstances on the other? Well, we just simply do not know that yet. :O

Friday, 12 September 2008

The chaos-theory

The day has come that we have been waiting for. Here is the Panasonic Lumix G1, the first Micro FourThirds camera and two new lenses. Now I have to compare my predictions to the facts.

Where I have made a mistake is the switching between aspect ratios. I predicted that the sensor will be wider than 17.3mm so the amount of pixels will not decrease in 16:9 mode compared to 4:3. I said it based on the LX3's solution. I can not understand the lack of it, the variable aspect ratio was published as a main part of Micro FourThirds concept. The images are 4000 pixels wide in all modes. This is not a switch between ratios, but simply cropping of the image.

My thoughts about EVF hit the spot very well. The G1 has a LED (alternating colour) illuminated 800x600 pixels LCOS display in the viewfinder coming from Panasonic professional videocameras. It is equivalent to an 1.44 MegaDots (800x600x3) conventional LCD. The refresh rate is 60fps which is quite high to composing and shooting without delay. The size of the viewfinder image is comparable to the one found in contemporary fullframe dSLRs and it covers 100% of the image. This is a very nice feature and an elegant answer to critiques targeting he "tunnel-vision" viewfinders found on entry-level DSLRs. Of course, EVF needs permanent power supply during composing so G1's battery life is not as good as modern dSLRs'.

I can offer an opinion about AF based on the dpreview's short video-clip only, but the implementation is very promising. The speed of the AF system is comparable to entry-level dSLRs' and is absolute unusual from the contrast AF method. As I said before this is the most important development (new focusing algorithm and high refresh rate) which allows the make of a non-SLR interchangeable lens camera. The 23 AF field is unique in this price category of dSLR's. Unfortunately, that warnings in the announcement about the limited usability of "legacy" FourThirds lenses with the adapter were in line with the most pessimistic expectations. The lack of AF with most of the available lenses is a very strong disadvantage and the most frustrating deficiencie of this system. The large Zuiko lenses look very impressive on G1 (or the other way round?), but I do not think that anybody will buy or keep $1000-$6000 devices to use them only in manual focus mode.

AF works only with following "legacy" lenses on Panasonic G1:
- Leica D Vario-Elmar 14-50mm 1:3.8-5.6 ASPH. MEGA O.I.S.
- Leica D Vario-Elmar 14-150mm 1:3.5-5.6 ASPH. MEGA O.I.S.
- Leica D Summilux 25mm 1:1.4 ASPH.
- Zuiko Digital 14-42mm 1:3.5-5.6
- Zuiko Digital 40-150mm 1:3.5-5.6
- Zuiko Digital 25mm 1:2.8

The size of lenses is very promising. As I wrote some weeks ago about the possible advacement in the wide-angle range, the new 14-45mm lens is much smaller than its anchestor due to difference in its design. Do not forget that it is also a stabilized lens, so stripping the lens from this feature, its size would shrink even further! I have seen only few sample photos, taken probably in JPG format, but they are quite good at first sight, especially in terms of CA cancellation and considering that this is a kit lens (by the way: I can not understand why F/13 aperture is used for samples on a 12 megapixel camera - maybe they have never heard about diffraction.) I have calculated the size of some lenses based on a photo using comparation method. The Lumix G 7-14mm is about 80mm (length) x 65mm (diameter). The classical version of this lens is 120mm x 87mm. The difference in size is terrific but we have to wait for the first photos taken with it, because it is very hard to meet the quality of the comparable Zuiko lens. I am sure the 20mm 1:1.7 will be very popular and is also very small: it measures 25mm (length) x 55mm (diameter).

The lack of movie recording is a little bit disappointing. It was the second most important feature when the system was announced and after the release of the Nikon D90, this feature was very much expected. I think its omission is a big marketing mistake. There is a special lens in Lumix G roadmap, however. The 14-140mm F4.0-5.6 O.I.S. HD will support all functions of video mode. Most importantly, it will focus also during movie recording, a feature the D90 misses badly. However, if only this lens will be usable for video recording, the system will lose the advantage of large sensor due to small apertures compared to very bright video lenses. We shall see.

In last years the principles of FourThirds system were compromised many times. Here belongs the camera dependent lens-firmware updating, the limited contrast AF, the RC flash mode wich is supported only by Olympus and image stabilizer mix-up by the two supporting companies. If the placement of the stabilizer in the Micro FourThirds will be as muddled as now, the standard will become a bit ridiculous. The confusion is evident given that the most frequently asked question among FourThirds users is: "What happens if both stabilizers are swithced on?" I do not think it would be a bad strategy if Olympus did not release many original lenses for Micro FourThirds. If they only relabel the Lumix G lenses, they can focus on the dSLR segment better.

Other features of the G1 are not attached to the system, but they show the strength of Panasonic. The rear LCD has 480x320 pixels which is the resolution of the iPhone but in smaller size and higher density. The 12 megapixels of the sensor is enough for A2 sized prints. I do not want to rank the image quality of the sensor before I have developed some RAWs on my computer. The HDMI output makes it possible to show your photos or to verify the image quality on large TVs.

The Panasonic Lumix G1 stirred up the people, the internet forums burn due to traffic. It is hard to draw the inference, and indeed, we should not draw them yet Olympus have not announced any MFT device, so we have to wait until Photokina or even longer - I am afraid we will see only a Zuiko Digital 9-18mm and some MFT mock up there. It looks to me that the real purposes of the two companies with MFT is to exploit their capacity and to sort resources ideally. Not bad to the consumer, I would say!

Monday, 8 September 2008

Monkey in the family

As I had promised some weeks ago, I completed my flash-holder arms. I would like to share my first experiences and some photos taken with them.

Update: new photos

The story started with a murder. I looked for two strong and flexible arms which have to hold the two FL-36R flashes. It was difficult to find them because the turning-moment is quite high due to the necessary length of the arms and weight of the FL-36R. After some tests I bought a Joby Gorillapod SLR Zoom version tripod and I have sawn it into three pieces. I made four aluminium caps onto their ends on turning-lathe. I had to ask for some help from my colleague to make the flash-shoes with a miller into two caps. After preparation of the arms the caps were fixed with two-component epoxy based glue.

the set-up in itself (click to enlarge)

So, there was nothing other to do but make the rack of the arms. I used a piece of an old shelf made of steel. I glued a thick rubber strip into its slot for prevent scratches on camera body and for solid fixation. The Zuiko Digital 50-200mm has tripod collar so I did not make sleeve-nut because I do not need tripod when I use shorter lenses. Due to the specially shaped rack there is enough room to my forefinger, so it is easy to hold the camera in vertical position.

holding in different positions

Last weekend I tried to take some photos of insects and wildflowers with my new equipment. The first experiences are very positive. I used to use two home made diffusors for my STF-22 twin flash when I had it. There was no enough time to make similar ones for FL-36R's but built-in wide-angle panels worked very well.

Wild chicory (Olympus E-3 + Zuiko Digital 35mm macro)

As you can see there are no visible shadows and the lighting is quite soft and natural. Accuracy of exposure is very decent from a flash-system that was not primarily created as a macro tool. The positioning flexibity is better than the STF-22 has, especially with longer lenses or when you use one of the flashes to light the background.

Small heath (Olympus E-3 + Zuiko Digital 35mm macro)

Of course after two days of using the arms I need more time and to have more experience to perfect this tool. There are many unanswered question and many things to do. It is the most important to give a name to this set-up. :) I am thinking about the standardized production but I have to estimate the demand and to calculate the real costs. Stay tuned, and I will share all information soon.

Sample No. 1
Sample No. 2
Sample No. 3

I have not got time to deal with standardized manufacturing so I give all information about this set-up.
photos of project

update II.:
Joby has announced the new Gorillapod Focus which can support up to 5kg. It would offer more stability for my set-up. The only problem is that Focus is too expensive and too nice to saw apart. (..but it is worth considering)