[geekkt]

So I have a question. I'm selling off some Pentax gear including my FA31 (that I bought used from a member here a year ago and have loved, have had no issues)

I've got it listed locally and I got a bite, but he asked me over the phone 1) where it was made, which is Vietnam, and 2) does it have a rattle when you shake it?

I held it up to my ear and yes, when I hold it tightly and shake it just a little there's a noise inside..I don't know that I'd even call it a rattle, it's not clunking, or loud, or metallic sounding, its quite quiet and maybe more of a "thunk thunk" or a "thump thump."

As I said, I've had no issues with it. It's definitely a lens that took a while for me to learn to use well, but it's been fine. Is there possibly something wrong I'm not aware of? I would hate to sell a faulty lens to someone. He did mention that there's a known issue with some assembled in Vietnam.

Thanks!

[kiwi_jono]

Well I'm sure some FA 31 owners will answer but as a general thing its quite a possible for most lenses to have a slight rattle because the aperture levers / blades etc often have a slight bit of play (plus if you shook it hard enough it might move the lever). As long as it was very slight.

[starjedi]

So I have a question. I'm selling off some Pentax gear including my FA31 (that I bought used from a member here a year ago and have loved, have had no issues)

I've got it listed locally and I got a bite, but he asked me over the phone 1) where it was made, which is Vietnam, and 2) does it have a rattle when you shake it?

I held it up to my ear and yes, when I hold it tightly and shake it just a little there's a noise inside..I don't know that I'd even call it a rattle, it's not clunking, or loud, or metallic sounding, its quite quiet and maybe more of a "thunk thunk" or a "thump thump."

As I said, I've had no issues with it. It's definitely a lens that took a while for me to learn to use well, but it's been fine. Is there possibly something wrong I'm not aware of? I would hate to sell a faulty lens to someone. He did mention that there's a known issue with some assembled in Vietnam.

Thanks!

I think what he means is wobble inside(not hood wobble). Generally it does not impact IQ as Pentax claimed but it indeed makes people worry.

you can try to hold hood and shake again to check whether the inside group wobble or not. It will be very clear if you have a inside wobble copy.

[virusn3t]

I recently recieve my 31 from Adorama, it say Ricoh on the box (so i believe is from the last batch, also Vietnam) and shake a little bit, it make a very subtle noise (i must shake on my ear and put a lot of attention to hear the noise), but i doubt this sound is bad assembly, there is no wooble on the lens.

Only thing i dont like to much (beside price tag) is the much stiffer leather(?) bag, i dont know is like this because its new; when i buy a 77mm from second hand, it was way more soft.

[K David]

Does it sound like something bouncing around inside or like a back and forth? If it's the latter, I would not be concerned. If it's the former, I may want to see if I could investigate further.

[bschriver11]

My brother just had a 3 year old 31 limited repaired,lightly used i might add.It seems it stopped auto-focusing and was caused by something coming apart inside the lens,wobble in the front of the lens was evident.This is a bit disappointing considering this is supposed to represent Pentax best.

[6BQ5]

After reading this thread I had to shake mine. Yep, there is a slight "lka-lka-lka" sound. I wonder what it is. Is an aperture control arm? The lens feels very solid otherwise.

[K David]

Mine makes a very low rattling sound that sounds like it's coming from the motor. It's probably due to the way that motion with a sudden stop causes a difference in weight (dynamic versus static load) on the connections between the motor and focusing helical. Most likely it's a normal thing and a measure that keeps smaller metal parts from breaking under sudden strains.

[hjoseph7]

Just went and shook mine just to be sure. NO rattle ! I'm not sure where mine was made ? It does not say on the lens Made in Japan or Made in Vietnam ?

[grahame]

31 Ltd has the floating mechanism to compensate for aberrations, particularly for close focusing. So I guess it should have a moving element? And maybe depends on the focusing status (far or close), you might notice some movement or not?
6BQ5, hjoseph7, can you refocus the lens to the other end and try again?
I ordered the 31 from pentax web store, and canceled the order. Should have waited. :-(. So I don't have one to rattle...

[6BQ5]

Hmm! No difference at infinity or close focus on my unit.

[Digitalis]

My MIJ FA31 has no rattle, there is a very faint tick which goes away once I apply tension to the aperture lever, however my FA31 has been modified by an expert optical technician by my request and the rear plastic baffle surrounding the exit pupil has been lined with felt, which fits snug against the rear cell of the lens - this is to aid flare reduction along with preventing dust and moisture from entering the lens.

Mine makes a very low rattling sound that sounds like it's coming from the motor.

The SMCP-FA31 f/1.8 Limited has no internal focus motor.

[K David]

The SMCP-FA31 f/1.8 Limited has no internal focus motor.

I stand correct. Gear train is what I meant in my brain. Please read my mind and not my words.

[Fat Albert]

My MIJ FA31 has no rattle, there is a very faint tick which goes away once I apply tension to the aperture lever, however my FA31 has been modified by an expert optical technician by my request and the rear plastic baffle surrounding the exit pupil has been lined with felt, which fits snug against the rear cell of the lens - this is to aid flare reduction along with preventing dust and moisture from entering the lens.



The SMCP-FA31 f/1.8 Limited has no internal focus motor.

Can you please post a pic of the felt mod?

[Digitalis]

Can you please post a pic of the felt mod?