SMC Pentax-DA 645 25mm F4 AL [IF] SDM AW

[larkis]

Does anyone on the forum own this lens ? I'm thinking of purchasing it and would like to get some feedback from someone who is using it.

[DandA]

Hi larkis,

I'm certainly not qualified to give first hand experience with this lens, but I received various image files since it's release from various owners who shot with this lens on the 645D and also had a aquantence communicate with an overseas photohrapher who shot with both the original version on film and 645D and the new updated version of this lens. My comments are only a distillation of both examing such files and the feedback from that photographer and the most valuable info is of course from those that own and use this lens.

It has good central sharpness, especially when stopped down at least an f-stop from max aperture and edges and sides lag behind a bit (by approx 1 to 1.5 f-stops but when the lens is well stopped down, excellent sharpness is seen across most of the frame. I also found contrast good, but from the images I reviewed, I cannot make a good determinantion of microcontrast as the # of different lighting senario's was not all that varied.

The one area which was a surprise and in some cases I was personally dismayed about, was the high levels of CA in side and backlit scenes.  It's easily provoked and readily apparent in most images that confront such lighting...of course it's subject dependednt.  For certain types of subjects, it would be a serious issue, especially if printing large or if CA is prominant over much of the image.  My hunch is Pentax is well aware of this and that is one of a number of reasons they revised the lens. The newer built in hood is obviously longer covering the front element to a greater extent than the 1st version of the lens.  The photgrapher who shot with both versions felt upon visual inspection that the newer lens may have different coatings as well.  His tests on the 645D seemed to show the newer lens exhibiting somewhat less CA than the old, especially in heavily backlit scenes, which was a great benifit.  Which version of the lens were you contemplating? Some are balancing out having this lens vs. a D800 with the Zeiss 21mm.  I wish it was somewhat less expensive.

There is another thread of someone who just tried out this lens and compared to his Pentax 35mm.  He found the 35mm at f8 sharper but both were good.  The link to that thread is http://www.luminous-landscape.com/forum/index.php?topic=67450.0

I also felt from my impressions that the 35mm is also sharper but again two different focal length lenses.

Dave

[larkis]

I'm contemplating the new version of the lens.

[gerald.d]

Apologies if this comes across as a bit facetious - it really isn't intended as such - but what the heck does all that mean in the lens name? I don't think I've ever come across any product, of any type, with such a complex name!

[tsjanik]

Apologies if this comes across as a bit facetious - it really isn't intended as such - but what the heck does all that mean in the lens name? I don't think I've ever come across any product, of any type, with such a complex name!

Has it been a while since you've looked at new lenses? e.g., Nikon 18-105mm f/3.5-5.6G ED VR AF-S DX Nikkor Autofocus Lens (White Box)

But to answer your question: SMC is the lens coating; DA is the digtial designed lens; 645,the format (sort of); 25mm, focal length; AL, aspheric element(s); IF, internal focus;SDM, focus motor; AW, weather resistant.

[leeonmaui]

Aloha,

I used this lens briefly in Paris, and then used my FA 35mm under the same indoor lighting conditions.
for the asking price I wanted to be blown away, I wasn't.
I think my 35 is sharper across more of the frame, I was stopped down to f8
distortion is really well controlled, maybe better than my 35mm
contrast and color look great, about the same as the 35mm which is really nice.
the front element is pretty bulbous, I can be hard on my gear, so that's kind of a worry for me if you shoot in dynamic situations, it certainly is something to consider.
I love wide angle lenses, and with the drop in cpf I was really looking forward to this lens.
If I had the spare cash, maybe....