SDM lens, safe to buy?

*ytterbium* · 08-13-2009, 12:04 AM

I've red numerous opinions about SDM lenses. Both good and bad, but when reading such qualitative information you tend to focus on possible issues.

So until now i've been unsure if it is safe or preferable to buy SDM lens. To have a better impression of how things are actually instead of seeing only picked descriptions of problems encountered i've made this poll.

I've offered answers that match my situation best.
If 1:3 votes would indicate bad experience i don't think its a safe option to invest your money in.

*Ash* · 08-13-2009, 07:13 AM

It's not safe to buy SDM - the motor emits supersonic radiation that fries bodily organs in close proximity to it.

But seriously, although you'll hear more problem stories than praise ones with any item, you're also going to get similar response biases with this poll, so I'd still take the results you get here with a grain of salt.

Just self-assess *why* you want an SDM lens and go ahead and buy your most coveted SDM lens from a reputable dealer with warranty. Then go all out with the lens!

*GLXLR* · 08-13-2009, 08:58 AM

I think SDM is reasonably fast. The only thing is it doesn't feel USM fast/quiet. Back when I owned the Canon 30D and a few lenses (among them the 28-70mm f/2.8 L and 35-90mm $20 cheap lens) I never noticed how fast Canon USM was (b/c in reality it WASN'T "fast" compared to my 50-135mm). The big difference was was how quiet and accurate the AF was. My 50-135mm would occasionally hunt around in doors (even outdoors it is EXTREMELY occasional). Also, SDM isn't super quiet at all. It may be much more quiet than the scratching sound of screw AF, but compared to USM (even non ring USM), SDM is comparatively loud. Don't get me wrong, it doesn't bother me at all, but it seems strange that Canon has had this technology since the 199 something and Pentax is only just starting to use it and even this technology is inferior to the super old 28-70mm i use to have.

I still have no idea why Canon USM is so fast...

I have never had a real problem with SDM before, but I have had to service my 50-135mm due to a loose MF ring. I later found out you can tighten this yourself...

I would still recommend it. If you have never tried USM before, then SDM should seem pretty fast/ quiet.

The AF hunting could just be my camera body though... the 30D apparently had super fast AF system.

opiedog · 08-13-2009, 09:33 AM

looks like there has been less reports of sdm failures this year, but nevertheless, there are and i wanted to get the 16-50, but still contemplating if the difference in price between that tamron/sigma and the possibility of getting a dud outweighs it.

the warranty of 1 year is way too short compared to the 4 and 6 year warranty from sigma/tamron.

*Ash* · 08-13-2009, 09:57 AM

SDM comparatively loud, GL?
How much louder could it be?
I never though that would be a point to consider whether to go SDM or not...

*GLXLR* · 08-13-2009, 10:14 AM

Originally Posted by Ash

SDM comparatively loud, GL?
How much louder could it be?
I never though that would be a point to consider whether to go SDM or not...

It's very quiet, but compared to USM, it's louder. ALthough I don't really care. I didn't switch over to Pentax from Canon and expect faster/quieter AF. THe sound of SDM is in between the sound a Canon 18-200mm (has a micro motor not quite USM) and a real ring type 28-70mm f/2.8L USM.

*ytterbium* · 08-13-2009, 11:51 AM

Results seem nice.
My main concern is 16-50. Which if safe to buy should be my goal.
If it is still too buggy and uncompleted i shall wait for some next revision like 16-50 II with real ring motors, or be able to save money for something like Tamron 17-50 much faster.