[pentaxian_tmb]

Having an issue with my SMC FA 35mm lens....After taking a picture with Auto aperture , the lens aperture will not open up unless I manually move the aperture ring back and forth back to auto?

Any idea what would cause this? Something fixable? If not, what is the modern equivalent for a replacement, as the price of this lens seems to have gone through the roof?

[pschlute]

Could be sticky aperture blades. Take the lens off the camera, set it to f22 and flick the lever at the rear. Do the aperture blades open and close smoothly ?

[Papa_Joe]

As pschlute stated it is probably a mechanical issue, those should be inexpensive to fix. So I would suggest you call the official pentax repair shop and ask them for a non binding estimate of the repair costs, so you have an idea for the amount to think about.

If repair is no solution, you are quite in a dilemma, as the cheapest modern equivalent is the same lens new, now with a HD coating. If you need it for APS-C you can go for a DA 35/2.4 instead. Every other solution will probably cost you more. Even if you are going for a used lens, a used FA 35 is the best bet. Because the additonal issue is that the FA 35/2.0 has a very, very high IQ besides the purple fringing wide open.

Nonetheless as modern equivalents there are the allready mentioned Pentax DA 35/2.4 AL (APS-C), the DA 35/2.8 ltd. macro (APS-C) which I would rule out as it has not the same IQ as the FA35 and the Sigma 35/1.4 Art (FF) which I own and would also not suggest as a replacment, at it is expensive and bulky and heavy as a tank and in my opinion does not pull ahead the FA35 in terms of image quality so much to negiate those three negative points. *)
Note, that other forum members probabyl have other opinions about the DA ltd. macro and the Sigma Art, but these are just my two cents.

*) I bought it for the 1.4 aperture, as I wanted an APS-C equivalent for a 1.7/50 on Full frame and I still ponder if I should not buy the FA 35 as well.