Originally posted by SFTphotography It does and it doesn't. With the 25mm you are limited to the ND, CPL and IR - but not graduated filters which a lot of us landscapers love to use and require to use. The 645x dynamic range is great but many scenes still can overwhelm even the best DSLR on sale. And yes, I know you can blend but it isn't always feasible, or practical. Sliding on a soft edge filter works so well for a lot of us.
I use a Lee 100MM system - but you can use Kase, Format Hitech etc. Neither are cheap to invest in but buy an adaptor ring, few GNDs and the expensive CPL and you can use it on any lens from any maker. I have the 82 mm adaptor ring for the 28-45 and the 77 for the 45-85 and various smaller ones so I can mount the holder to the lens and use the filter accross my entire lens system. I've used Lee filters for nearry 9 years on countless different camera systems. 82 and 77 are the most popular filter thread diametres but 67, 62 and 56 come up. Buy one 105mm CPL and mount it to the expensive filter holder and you are covered no matter what the lens you use.
Word of caution, with longer FL's you don't really need filters and they degrade the IQ. Anything beyond 50mm or 35mm equivilent and I wouldn't use anything.
All true, but it is pretty simple to diy an adapter so the 25 can take large filters. Here is an excerpt from the Hark Lee DFA 25 review here at PentaxForums:
"(6) Using GND Filters - Custom Filter Holder
Since nobody has manufactured a dedicated filter holder for this lens, I had to fabricate one from a cheap abs pipe and Cokin z-pro filter holder.
At Home Depot, I picked up a small end cap hub that has a slightly smaller diameter than the front section of the lens, cut off the cap part,
converted it into a short cylinder and glued it to the back side of the Cokin Z-pro filter holder. I had to bore the cylinder a bit for a proper
tolerance and lined it with black velvet. FYI, after wasting a fortune on a number of different materials, I settled down on fake adhesive velvet
that I picked up from Daiso. After cutting and grinding, spray painting is a must and now you have a custom filter holder. You can use one 4X6
rectangular filter without vignetting."
Read more at:
https://www.pentaxforums.com/lensreviews/SMC-Pentax-D-FA-645-25mm-F4-Lens.html#ixzz70APWCeX7
Thanks,
barondla