Photoclubalpha

I was not aware of lens gear getting stripped, until it was too late. my sigma 75-300 was fine until i used it on A700 it is know jammed solid.
I could not afford to have the lens repaired I carried on using my Minolta 24-105, it worked OK until last week when it started to miss focus and then jam.
In the space of on month I have gone from being a proud happy owner of a fairly competent piece of kit, I am left with a body only. Why was this problem not made more public.

Somehow I am not surprised of hearing that Sigma got jammed or whatever... But I am surprised to hear the same about Minolta.
In case you get them fixed do tell us about the reason(s).

Hi Mike & Welcome...

Sorry to hear you were not aware of the gear stripping due to the fast speed. I was fortunate enough to have read about it by David K, then sold my 70-300 APO which I really liked. David did mention you could set the A700 to normal AF rather than use fast AF speed. Not sure why this is not made more public? it really is the Pits!

David A

Should I worry about my Sigma 70-300 with my a200? I don't remember seeing anything aboug fast AF in menus. However I often use continuous AF with this lens.

Hi Hawk... I don't think the A200 has that Normal/Fast Speed option of the a700. I have the a200 which is quite fast so did not take a chance!

Why was this problem not made more public?

What problem? Do you have a link to somewhere where the problem is described in detail?

It certainly isn't easy to google up any details based on the few clues you've provided. However, since this is a handy thread title in an appropriate forum let's try to make it more public for the benefit of others. I'm assuming that you're referring to the problem of certain Sigma lenses having weak plastic lens focusing gears which the fierce strong focusing motor of the Sony A700 is likely to strip. If that is the case I'd expect it to be most manifest on big lenses with plenty of inertia and focusing movement such as some long tele zooms. It might also happen with some other lenses which move external parts of the lens on focusing if the movement was impeded, such as letting the moving lens ram up against a wall, or holding a manual focus ring which is being spun by autofocus too tightly. There seems to be mention or at least suspicion of all those problems in dpreview's and dymax's forums.

I saw a suggestion that the focus motors of the A200,300, & 350 might also be fierce enough in operation to cause a liability to at least some of those problems. I also saw mention that the A700 has a menu option for selecting between fast and slow focus. Is this the case, and if so, is it provided in order to be permit older lenses with weaker gears to be used successfully with the A700?

I'm hoping that among the multitude of comments that can be found on these issues there is somewhere a good authoritative summary of the problem you're talking about, and that someone here knows where that is

thanks for replies i remember David Kilpatrick from the first time i had a Minolta 500 ten years ago he was always ready to reply to correspondence and phone calls with great patience if he reads this please accept my regards.
unfortunately i have just been made unemployed and money for lens repairs is not a priority, to be honest should have sold the lot when had a chance and gone canon.
cogs, screws and gears their a joke in this day and age.

Canon have had exactly the same problems - my Sigma UC 24-70mm for Canon jammed and stripped its internal motor (buzzing sound, no focus) and Sigma replaced it. The problem with Sigma 70-300mms is known, and it is due to using plastic gears against metal, resulting in stripped gears. Also, the A700 focuses faster than Canon or Nikon models using certain lenses - kit lens 18-70mm is a good example - and the future consists of SSM lenses for the system. Two or three years from now very few of the lenses will still be mechanically driven but I think some of these will be in demand.

I don't know of any problem with the 24-105mm. Your Alpha is almost certainly still under warranty (all 700s are under one year old). Sony do say that the camera is backwardly compatible with Minolta lenses, and the 24-105mm is a recent D series design which they themselves have carried through to the new Sony range. I would suggest that damage done to the lens AF gearing by the A700 qualified for the camera and lens to be sent to Sony for servicing, as it is possible for the in-body motor to be wrongly calibrated for speed and 'initialization' sequence which is what normally damages a lens. You might get the lens repaired under the body's warranty terms.

The only lens to be cautious with on the Alpha 700 with AF set to high speed is the 80-200mm HS APO which can be driven faster than the mechanism can cope with, but I've not heard of any breaking yet.

David

mikehawthorne wrote:thanks for replies i remember David Kilpatrick from the first time i had a Minolta 500 ten years ago he was always ready to reply to correspondence and phone calls with great patience if he reads this please accept my regards.
unfortunately i have just been made unemployed and money for lens repairs is not a priority, to be honest should have sold the lot when had a chance and gone canon.
cogs, screws and gears their a joke in this day and age.

With the 24-105 problem you mentioned, is it focus related for sure? I know the odd 24-105 has been known for having a zoom cam follower/roller screw coming loose and causing a jam (easily fixed), but I haven't heard of one stripping the focus rack...so far anyway.
Greg

I took David Kilpatricks advice and contacted Sony regarding jamming of focusing gear on my 24-105 Minolta lens.

Their reply i could not believe they said this lens is not on our list and therefor is not compatible with a700!
can you believe this as i cant. any views please.

Yes, they have advertised the system as compatible with over 20 years of Minolta AF lenses.

I've sent a copy of this to Paul at Sony UK for a reaction.

David

as always david you always take positive interest.
thanks

mike hawthorne

mikehawthorne wrote:I took David Kilpatricks advice and contacted Sony regarding jamming of focusing gear on my 24-105 Minolta lens.

Their reply i could not believe they said this lens is not on our list and therefor is not compatible with a700!
can you believe this as i cant. any views please.

It is listed as compatible on their website (assuming it is the 24-105/3.5-4.5 (D) Code 2672 - I am not sure if there are other versions).
See http://support.sony-europe.com/dime/dig ... selLens=KM (or, at least, perhaps somone at Sony should!).

I suspect your 24-105 just had a stand alone issues not related to the AF drive on the A700. As David mentions even Sony sold this lens.

But more so, I don't think any Minolta, KM, Sony, Sony-Zeiss lenses should ever have an issue. They all have official ROM/Lens IDs. On any lens made by these Companies they would have flags for the lenses that need to go to the low torque mode. This would be an easy thing for them to do, and they have the specs as to what every one of these lenses was designed to handle. The question would be if any of these lenses need to go to a low power mode. I would guess no, but maybe a few do. Maybe Sony didn't implement such a built in torque mode, but I would have a hard time believing they wouldn't as it would be very easy to do (literally a few lines of firmware) and save them any risk of damaging peoples gear. Doesn't matter if they damage 3rd party stuff, they can't do anything about those and it will just cause folks not to buy 3rd party.

David Kilpatrick wrote:Yes, they have advertised the system as compatible with over 20 years of Minolta AF lenses.

I've sent a copy of this to Paul at Sony UK for a reaction.

David

Paul has asked for more details, and would like to take this - including whether the statement was made by phone, or email, or in writing. He says the 24-105mm Minolta is fully compatible and this should not have been said. He would like know exactly what the fault is and you may now get some help.

David