Playing With Lenses: Flower Power: SMC Pentax-A Zoom 1:4 70-210mm

Cost: 29.99$ (average market price $86.93)

I was both excited and reserved to try this lens. At one side, it's an 80's zoom, not a prime time for zoom, but on the other hand, it was getting really good reviews online. My experience is somewhere in the middle.

It's a beautiful, well designed one-touch, slide to zoom and turn to focus, lens of epic proportions, with a nice build-in hood. To get to a fast F4 across the whole zoom range, zoom lenses of this time had to be big, until more compact lenses were designsed. My Sony camera almost disappears next to it. Yes, it's large and heavy with a lot of solid metal. The weight of the barrel alone seems to cause a lot of zoom creep with many users. I did not really had that problem, unless I held the lens completely vertical. Both zoom and aperture were extremely smooth, almost as fresh out of production.

This lens is capable of being very sharp, but when using large apertures, it does show some problems with sharpness and severe purple color fringing. So as long as you remain a few steps away from open aperture, and avoid maximum zoom, the quality is excellent. However, due to the size and weight, it's really hard to focus properly (manually of course) when using it handheld, resulting in a high percentage of wasted pictures. It should be used on a tripod, but as it does not have a tripod attachment on the lens itself, and lacks the space to put on a lens collar, you have the mount the camera itself on the tripod. And this lens is just to heavy to be carried by the camera mount alone, again resulting in less stability, and therefore less sharpness. So, capable of good quality, but not practical in usage. I prefer a more modern zoom design that is more compact and has less weight.

From online reviews, it seems this lens really shines when being used for close-up photography, especially with 8 blades giving potential for a smooth Bokeh. I did not have the opportunity to try it out on my walks as it is getting a little late in the year for flowers. So, a good excuse to take this lens out again in the summer for some Flower Power.

To combat partial reflection, Pentax developed chemical coatings for the lens surfaces with minimum light loss. SMC is "a remarkable seven-layer lens coating process that cuts the reflection ratio down to just 0.2% per lens surface. The result is a dramatic improvement in both color fidelity and brightness and the elimination of flare and ghost images."

SMC was patented and first applied in 1971, when Pentax was still making screw mount equipment. The multi-coated lens lines changed from Takumar and Super-Takumar to Super-Multi-Coated Takumar and later on to SMC Takumar. SMC Pentax was used for the newly introduced K-mount lenses. Pentax's SMC is still today considered as one of the best lens coatings on the market.

Lens Specification:

Focal Length: 70-210mm
Maximum Aperture: F4
Minimum Aperture: F32
Image Format: 35mm
Lens Mount: PK
Optics: 13 elements, 10 groups
Blades: 8
Focussing: Manual
Minimum Focus: 120cm
Filter Size: 58mm
Weight: 680g
Length: 149mm
Production: 1984 to 1988
Serial Number: 5249729
Made in: Japan
More information on Pentax

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