Snap with Pentax A28/2.8

On a Pentax DSLR, the view angle of the A28/2.8 is equilvant to a 42mm on 135 film body, which is a very classic focal length. A 40 or something focal length is the 'normal' lens in the old days and many camera such as Rollei 35S or a lot fixed lens rangefinders were equipped with a lens of similar focal length.

Still remember how Pentax advertised when it launch the FA43/1.8 limited? Pentax said the 43 is the true normal lens for 135 film. To the same reckoning, 28mm should be the true standard lens on DSLR body.

Before I get the DA21/3.2, I very often use my old A28/2.8 as a small lurk snap setup. My snap with this lens are not very successful because the streets in Hong Kong is quite tightly packed, and I often wanted a wider lens. In a spacious environment, however, the view angle of the 28mm is just great.

Another problem is MF. To me, AF is important in snap shots because I take a lot of off-finder shots. I can adjust the focus to approx. 3m or 2m without looking at the camera or lens, that just took me a little practice. But that's only an approximation. I still took a lot of out-focus shots.

Someone said you can use zone focus technique with the 28mm on a DSLR. I tell you, you will not be satisfy with the image quality. First of all, the Depth-Of-Field scale on the lens was for film, not APS size CCD. A quick calculation of DOF tell me I should give 1 more stop down (ie. when read the f/8 scale on the lens, I should use f/11 to shot). secondly, the DOF pinciple only hold true when you view the photo 'normally'. ie. at approx. 4R size on your screen. Don't you have the temptation to view the image at 100% pixel view? I did. The DOF is much more strict at 100% view and even it's within the DOF, it's not sharp enough.

So how good or bad is the image from the Pentax A28/2.8? I am sorry that I cannot conclude about this. I mainly use this lens for street snap (st. doc), which I always shot in jpeg. My quick shoting habit in snap and the softness of my istD's jpeg prevent me to judge the image quality.

I will try to dig out some correctly focus picture and post in this blog again as sample photos.