55mm 1.4 SDM failure --> use with MF or send back? help

hello,
i've just acquired a DA* 55mm, it arrived yesterday. The seller said he bought it new and used it twice, but hasn't used it for the past 2 years. Now it arrived and the autofocus doesn't work. Known problem.
The price was very good, but still it was supposed to work.
The seller is offering for me to return it or give me a discount (i don't know for how much). I've tried it in manual and the results are great but manual focus is a pain (it's mainly to shoot my kids indoor so a lot of movement).
Question is: is the AF (when it works) good enough or do people end up using it on MF anyway?

I need to reply today on whether i keep it or not..

thanks!

Keeping up with kids usuing manual focus is tough so I would return it. Whether or not the AF on a fully-functional DA* 55mm is good enough to keep up with kids is another matter - I've heard AF is slow but have never tried it. Given that the AF on a working one is likely to fail before long, is getting one a good idea at all?

thanks, yes i tend towards that, i have to say the bokeh is pretty impressive, sometimes the colours are also very good (i've been shooting with light coming from different directions inside the flat, very different results), but i also have a 55mm 1.8 K which is also very good. The plan was indeed to get an AF lens (i also have a FA 50 1.7 which is OK) for portraits, as you said the life of those lenses is sadly limited, shame Pentax isn't producing the same but without this issue. I find the size and weight to be perfect.

It depends on the discount. It's a great lens when working correctly.

I actually wouldn't mind purchasing it from you in order to attempt an AF fix. PM sent!

Are you using it on full frame or APSC. A Sigm 30/1.4 on APSC might be another alternative.

i am using it on a KP so APSC. I have a FA 50mm F1.7 and would like a faster / nice bokeh portrait lens, not that the 50mm is bad, but i find 55mm to be more portrait like somehow.

Alternatively buy a 50-135 and convert to screwdrive. It's an unbelievably good lens!

The f/2.8 aperture isn't a big limiting factor for portait shots, and it has wonderful rendering.

Not meaning to take this off topic but the alternative portrait length Pentax lens for APS-C is the DA 70mm Limited. It's an excellent lens and doesn't have SDM to fail, it uses the old screw-drive AF method.

Or the FA 77mm f1.8.

Steve

I have had a copy of this lens for years - AF response is good and the image quality is superb. While other SDM lenses I have owned, particularly the 50-135 have suffered from drive failure the 55mm has never faltered.

Would a DA 35/2.4 be fast enough/good enough?

Is the DA*55 able to be coverted to screw-drive like the 16-50 and 50-135? Or is it like the 17-70 which is SDM only? I nearly bought a 17-70 years ago (when my DA*16-50 was being fixed for the first time), new from Jessops in Richmond - and it did not work.

If there are no means to convert the lens to screw drive I would return the lens.

It cannot be converted unfortunately as it has no screwdrive built-in.

Then I would suggest OP returns the lens.