Medium format camera systems historically focus their glass selection towards landscape, portrait, and studio photographers. Because of this, thankfully, there are many choices in the medium telephoto range. At a 35mm equivalent of 96mm on film bodies (125mm on the 645D), this 150mm prime will give you a versatile field of view for both portraits and landscapes. It was eventually replaced by the auto focus 150mm 2.8FA for double the money. As with most of Pentax's 645 line up, the FA lenses added auto-focus, but did not make considerable leaps forward in optical performance.
- Max Aperture - 3.5
- Min Aperture - 32
- Filter Size - 58mm
- Weight - 448g
- Length - 72mm
- Min Focus - 4.6'
While this lens is more compact than it's FA counterpart, it accomplishes this by focusing externally. This means that the barrel moves in and out during focus, a minor performance compromise. The filter ring does not rotate however, so polarizing filter use is not impaired.
Focusing is very fluid and dampened nicely. You tend to hear a ton of praise for Leica and Zeiss lens construction. I've found the manual focus Pentax 645 line up to be on par with the aforementioned small format lenses. I think this is why they stuck around so late (the 645N didn't get released until 1997). Please take note that the minimum focus distance is just shy of five feet. If you are shooting tight head shots, this will not be close enough.
For anyone that has read my lens review on the Nikon 200 f4 or the Leica 90mm 2.8, you know how much I love built-in lens hoods. How we have let Canon and Nikon get away with packaging cheap plastic hoods with $2,000 lenses is beyond comprehension. This integrated hood is not only as tight as the day it shipped from the factory, but it sports a rubberized end for protection.
The size of this lens is what makes it special. When compared to similar focal lengths in the 645 format, you get a great optic in an efficient package. I sought the 150mm out as a complementary lens to my wide angle for backpacking. The form factor is so similar to the 35mm 3.5A, that I no longer worry about rearranging my camera bag inserts. It doesn't matter what lens is mounted to the body, the camera fits in perfectly. A negative when it comes to versatility is that it's not compatible with the 1.4x teleconverter. This is a huge bummer since it would have been a great addition to a lightweight kit.
I was super skeptical about this lens for landscape photography. Would it be sharp enough under critical inspection, or blown up to large prints? Well I was surprised to find that this $120 special performs more than adequately for my use. Unless you absolutely require auto focus, I would stick to the 150mm 3.5A over the 150 2.8FA.
The longer I've been practicing photography, the less interested I am in performing laboratory style performance testing. But use in the field has netted stunning images with outstanding sharpness. It's amazing that you can find a lens for less money than its focal length value and be able to produce images worthy of 20x30 prints.