The hidden bonuses
Along comes the Alpha 55/33 design, and everything is solved in one step. A single motor can drive the shutter cocking and lens aperture actuation (the AF motor for screw-drive lenses is separate). These are very low energy systems compared to the mirror action of a conventional DSLR. A fairly unstressed shutter (low mass, low velocity) can still be operated 10 times a second but the aperture mechanism of the lenses was never made to operate faster than about 5.5 time a second, so it is fixed during sequence shooting.
There is no need for ‘mirror lock up’ because the camera always has the same lack of vibration found with MLU. Having no mirror shock means than nearly all pictures taken with the SLT models at shutter speeds around 1/15th to 1/125th, with or without SSS sensor based stabilisation, end up sharper. This camera produces pictures with the same sharpness than a Contax G or a Leica M can achieve, given a steady grip and a good lens.
These rangefinder-type cameras were wonderful to use, but never offered even vaguely accurate framing. The viewfinders typically showed frames with around 90% of the final image, the user being left to allow for the ‘real’ view. At close distances, errors could be substantial and it was never practical to have lenses focusing much closer than one metre. For that, SLR cameras took over.
Now the SLT design offers a perfect 100% view of the actual image received by the sensor. It is not just a 100% view from the same lens (like the Alpha 900) but a view of exactly what you will record. This means that it copes perfectly with any optical system attached to it, for any degree of close-up achieved by telephoto or macro methods, any degree of wide angle.
It does this using auto gain in all exposure modes except Manual, and that means the aperture of the lens is irrelevant. If you were to attach an f/16 Dallmeyer New Large Adon telephoto lens from the 1920s to a DSLR, the finder view would be so dark it would be hardly worth trying. Attach this to an Alpha 55 and it will, in daylight, look just as bright as the view from an f/1.4.
Further to this, the EVF reflects the actual depth of field of the image. Optical viewfinders do not, they overstate depth of field at apertures wider than f/4 or f/2.8, depending on the screen type. The A55/33 depth of field can be examined using a magnified view even with your eye to the finder. The camera has a depth of field preview button to stop down lenses, and this actually works – almost for the first time in the history of AF SLRs of any kind.
The Sigma 8-16mm used with the rear screen in waist-level mode, with the Horizon Level display of the camera aiding the alignment, at 8mm.
It keeps getting better. Wide-angle lenses, such as the Sigma 8-16mm f/4.5-5.6 which I have been using on the Alpha 55, are very badly matched to normal focusing screens. They provide a very dark view which may also fall off towards the corners in an extreme way. But when you use one on an SLT, the sensor has already been mapped for basic vignetting. It won’t provide individual lens corrections (in this generation of cameras anyway) but you get a fully bright, clear wide angle finder image with fairly even illumination accurately reflecting the final result.
The viewfinder image for this picture showed no sign of the sky or the sun at ALL – everything above the horizon looked plain white. The flare? We’ll come to flare later. This is not all from the A55, that on the left is a result of the 16-80mm CZ lens fitted with a multicoated filter which should have been removed, but this light lasted for such a short time there was no chance.
What the EVF can not do is show you all the detail present, especially in the shadows and highlights of contrasty scenes. Nor can it preview the true colour of your final image. It is in both respects a disappointing view of what may turn out to be a far better picture. The Alpha 900 optical viewfinder is seductive; you may photograph ordinary things because they look great through it. The Alpha 55 works the other way round. If it looks like a successful shot through this finder, it will be probably be a masterpiece! You may improve your photography just by having this simplified, limited electronic image to judge your compositions by.
Ultimately, it’s down to taste and habituation. If you keep switching to optical finders on other cameras, you may not learn to love the EVF. I shot using nothing but electronic finders (NEX-5 rear screen, Alpha 55 EVF and rear screen) for over 1,000 pictures in one week where the results mattered. I know what pictures I lost and which pictures included unwanted details I might have spotted with my Alpha 900 to the eye. This was all down to working methods, not checking the shot visually (direct, before framing it), not leaving the camera switched on, not using eye-start AF. I also know which images were improved by using the EVF with its 100% view and fairly accurate preview of exposure compensation.
The only way you can find out for yourself is to use an SLT model (Alpha 33 or 55) for more than a few minutes. It is very important to adjust the eyepiece dioptre. With an SLR, there is some scope for your eye to compensate for small dioptre errors, or partially compensate for larger ones. With the EVF of the SLT, that leeway is non-existent and the whole optical system is a much higher magnification ‘telescope’ viewing a very small display. Use prescription glasses helps, but really careful adjustment of the dioptre (not easy to get at or turn) is vital.
Here’s an example of an interior, lit by a door. The eye compensates but sees a dark scene. The EVF of the Alpha 55 sees whatever exposure you set. Here, ISO 800 and 1/30th at f/4.5 with the CZ 16-80mm at 16mm gave a highly detailed shot and it was easier to judge the illumination through the finder than by eye.
You should also check the finder in bright sun and darker conditions. I was able to use the camera in extremely bright sunshine (Fuerteventura, a subtropical latitude and desert landscape) and also at night. I now know that high contrast is the condition it handles least effectively, it’s able to handle extremes of light level, but not in one picture!
It is also important to turn off image review. At first, I tried to shoot with 2 second review of images; it’s not needed, as the preview image is generally exactly like the subsequent review due to exposure being calculated from the sensor. It slows down operation so much that any benefit is minimal. I even keep the rear screen folded away, reversed to the camera back. The EVF has got me working much as I did with film, trusting my knowledge of exposure compensation combined with the electronic preview of the result. I no longer need to ‘chimp’ my images, and I have not been let down.