Do you have a 25mm? I understand folks have been very pleased with this lens on a 645D.
Yes, agree, those I've spoken with have been please except for excessive amounts of CA rearing its ugly head every once in a while.
Tom, if it was simply a revision of the hood design I think they would have offered a retractable hood for both cropped and full frame sensors. I believe its more than this. Pentax spoke about coatings I believe, so I would guess three changes. The first being the hood. The second, additional glass surfaces are coated or multicoated..or maybe used a newly developed coating. Lastly they have hinted about the difficulty of manufacturing the original lens for full frame (labor intensive), due to the limits of element alignment for such an ultra wide angle used on full frame 645....and so the revised lens has some sort of simpler assembly.
The question is if one had the current 645D and hopes that Pentax might have full frame 645D in the future....would they go for full frame 25mm original 25mm lens or the new version...not really knwoing if full frame 645D will or won't ever be produced. Let's assume new 25mm does have a small but real performance advantage when used on current cropped 645D when compared to original version of this lens.
I think Pentax needs to elaborate on all this. It may simply be that the original version will no longer be made and we are simply discussing remaining stocks of the original lens....as Pentax feels once they go to full frame 645D digital, the FA35mm will surfice as a (thee) ultra wide angle lens for this system due to its approx 21mm field of view on full frame 645 (in 35mm terms.).
Why are we stressing over all this? Hasn't the new D800 superceeded the 645D is the performance catogory? Thats what they say over in that other wildy popular forum! (you know I'm just having a bit of fun since both bodies are remarkable performers, with each skewed towards a somewhat different role and application).
Dave (D&A)