Kiron / Lester A. Dine Macro 105mm F2.8

Ergonomics

Three characteristics of the lens are readily apparent on first use...

• Firstly is the 624 gram mass; by comparison my Tamron 90/2.8 (72B) (mixed plastic/metal build) weighs in at 428 grams**
• Second is the very generous focus throw, a full 720 degrees from infinity to MFD (more below)
• Third is the smoothness and ease of operating the controls

The weight is more than twice that of the Pentax-M 105/2.8 and only 56 grams less than the Pentax-A 70-210/4 zoom. It is that last point that puts things in perspective. I own the Pentax-A 70-210/4 and regularly shoot it hand-held and on tripod without a special collar. With the Dine, I shoot infinity to about 1:3 hand-held with little trouble and from 1:3 to 1:1, I work on tripod. Handling when used on my K-3 is similar to the 70-210. The same is true for my K-mount film cameras. One might also note that the Dine is only 24 grams heavier than the Pentax-FA 100/2.8.

The focus throw is similarly interesting in that most of the first full rotation is very well-suited to general use as a longish portrait lens with very generous movement to allow fine focus. Many macro lenses near this focal length have very limited rotation beyond about 7' and not much better from 4' to 7'. Moving to the second full rotation and one gets a full 360 degrees of focus movement from 0.5X to 1.0X.

Lack of auto-focus is not an issue for extreme close-up and true macro, but might be a consideration for some users for other uses.

Other Usability Considerations

• Exposure automation -- my lens has a PKA mount and supports all exposure modes on Pentax dSLRs as well as P-TTL flash.
• Hood -- The dedicated ring flash is intended to double as a hood. Without the flash, the front element is fairly exposed such that a hood is strongly recommended. I use a generic cylindrical metal hood.
• With flash -- as noted above, the lens was generally sold as kit with very nice ring flash. Working examples may be found on the used market. Other lighting is also possible, though consideration should be made to account for the extension at close-up and macro distances.
  
  Note regarding P-TTL: I have not used this lens extensively for closeup work using P-TTL flash, though it should be noted that gross overexposure may result from a combination of close distance, high ISO, and wider apertures when used with PKA mount lenses.

Performance

To be brief, my first foray into the garden for a test session resulted in the shot below being "explored" on Flickr with over 48,440 views at last look. The lens is easy to focus, is sharp, has very nice bokeh, and very pleasing colors. The lens is sharp, has excellent contrast, and is resistant to flare.

NOTE regarding chromatic aberrations and purple fringing:
My initial assessment was that the Dine is very well corrected and free of both LoCA and LaCA. That assessment essentially stands for natural light photography of most subjects; however, I returned to the question of purple fringing (PF) and was able to provoke PF on my K-3 with full sunlight on crumpled aluminum foil at f/5.6 and wider and again overexposed with direct flash. Under similar conditions, mild far LoCA was also noted in OOF areas on sunlit chrome. The most concise characterization I can make is that the greatest risk is with areas of intense (fully clipped) full-spectrum light; attention to lighting details when that is controllable is the remedy.

• Optical performance
• Build quality
• Ease of fine focus
• Long focus throw
• Usefulness for non-macro tasks
• Exceptional rendering and bokeh

• Relatively heavy, may be an issue for use, handheld
• Very long focus throw may be clumsy form some uses
• Significant purple fringing when provoked, despite excellent LoCA control