Pixel-Shifting At The Coffee Stand - Olympus In The Studio

Ever since the Olympus company announced that their new cameras could make images with more pixels in them than were on the sensor, I have been longing to try it out. The literature made it sound like they were lifting themselves up by their electronic bootstraps...

The trick needs a studio with constant lighting...which I can organise. It needs a camera on a sturdy tripod...my Gitzo Studex 5 certainly qualifies. It needs subjects that do not move at all...and my collection of miniature cars is ideal for this.

The function revolves around the fact that the Olympus engineers have made the image stabilisation mechanism on the sensor for the new OM-D E-M1 mkII move sideways and up and down by extremely small amounts - pixels - and with great precision.

This allows the camera to present a slightly different portion of the Bayer array to the incoming light over a series of exposures. Multiple images are put into the buffer with slightly different colours for each shot, plus a shot taken to allow the camera's computer to subtract electronic noise. Then they are recombined into one image that contains far more information than could be packed into it with one shot.

The multiple shots are not spaced out much in time. When I pressed the button down on the camera it was done in about a quarter of a second - the electronic shutter inside doing the 5 shots in that time. The lighting was simple tungsten modelling lamps from the Elinchrom studio lights and the camera was left to decide an effective white balance. After the shot went off it needed a couple of seconds to do the computer work inside.

Does it work? Yes it does. Here are two shots of the dashboard on a small Maisto model of a 1961 Volkswagen ( Yes children, dashboards were really that simple...no LCD screens and MP4 players... )  Shot A is the multiple detail shot while shot B is a standard exposure at 1/160 second.

One thing I did notice, though... when I shifted to the detail mode the manual aperture selection for the 25mm f:1.2 lens would not close down past f:8. Normally it can go to f:16, and this is desirable for the extra depth of field it gives. I suspect that it is deliberately limited to prevent diffraction effects through the lens masking the gains produced by the shifting mechanism.

This would make for a real balancing decision when doing close-up shots - they always need more depth of field. Fortunately Olympus also have another technical triumph in their camera to deal with that. Where the current pixel-shifting would be most use would be with setups at a moderate distance. or perhaps even with flat art copying of extreme detail.

Note: the only chance you are going to get to use this feature will be when you are using Pro-grade glass on the front.

Waiter, Bring Me A Pentax K-1...

And a side order of D-FA lenses too, please...

The New Pentax K1 was here for us to see at last night's Pentax Launch at the shop. As you can see from the pictures, interest in it was widespread.

Well, that has always been the case - as far back as the days of the dear old Asahi Pentax SV and Sla, Pentax fans have been loyal and since the cameras were always good value for money, there have been a lot of fans. When the Spotmatic hit the market like a bombshell in the 60's people discovered that there could be style and grace in a camera design as well as technical ability. Such would appear to be the case right now.

The K1 is the first of the Pentax full-frame DSLR cameras - that's 24mm x 36mm on the sensor - and they have aimed it carefully at people who want to work to the maximum sharpness with their photography. Here's how:

a. The sensor itself is larger than hitherto. Twice the area.

b. The sensor has no anti-alias filter to smudge the resolution. For those who worry about the appearance of moiré patterns in this case, Pentax have incorporated a small pixel-shake mechanism as an optional setting that can eliminate this.

c. For the people who are prepared to use the Pentax K-1 on a tripod and trigger it with a cable release or the self timer, there is the facility to take 4 pictures of the same scene while the sensor shifts ever so slightly. These four pictures are then combined in-camera to yield far higher resolution - up to 36.4 effective megapixels.

d. For the people who are taking pictures where they cannot use a tripod, there is a 5-axis anti-shake mechanism to damp down the effect of movement. Up to 5 shutter speed levels can be improved. Even the difficult movement of roll can be compensated for.

e. The smudginess that comes from diffraction on lenses when they are stopped down past about f:10 is a problem for tabletop and landscape shooters - Pentax has incorporated diffraction correction algorithms for a number of their lenses. Sharp edges, finer detail.

f. Ditto for the image distortions that are inevitable with some designs of lens - again some Pentax lenses can have this ironed out automatically in the camera's electronics. Result? Straight lines where straight lines are needed.

Now it may be some time before this columnist can get his mitts on one of the cameras and a suitable Pentax D-FA lens to do some field or studio testing, but he will do so AS SOON AS HE IS PERMITTED* and will publish the results. If sharpness is your game, keep reading.

* In the meantime talk to Bob Lichfield who has the ear of the Pentax people. He has it in a small box in his desk.