Author Topic: !! I  (Read 4858 times)

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Offline gillymaggoch

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!! I
« on: July 13, 2009, 08:53:36 PM »
I recently purchased a lens on ebay. The seller said it would work with my 300!
It does work but only in the manual mode.. the auto focus does not work This lens has five contact points on it my camera has eight ...is this going to make a difference when I consider buying another lens on ebay..

Offline harveyzone

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Re: !! I
« Reply #1 on: July 13, 2009, 09:02:55 PM »
I recently purchased a lens on ebay. The seller said it would work with my 300!
It does work but only in the manual mode.. the auto focus does not work This lens has five contact points on it my camera has eight ...is this going to make a difference when I consider buying another lens on ebay..

What lens was it?

Having just 5 contacts is not a problem. It is just an older lens - only the newer ones have 8. Most of mine have only 5 and work fine.

Tom Harvey

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Offline winjeel

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Re: !! I
« Reply #2 on: July 14, 2009, 05:09:44 AM »
Can I guess that the lens is a Sigma?
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Offline harveyzone

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Re: !! I
« Reply #3 on: July 14, 2009, 09:06:26 AM »
Can I guess that the lens is a Sigma?
That would be my guess too.

Tom Harvey

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Offline Rogbear

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Re: !! I
« Reply #4 on: July 14, 2009, 01:39:25 PM »
Yep I reckon it must be a Sigma too. I have a Sigma Manual focus 300mm telephoto lens as a lens it is quite good but the manual focus can be a pain. Best used on a tripod IMHO. I have since purchased a Sigma 200-300 Telephoto with Autofocus that is much better. Both bought on eBay at good prices plus a few others.
Please forgive any spelling mistakes I have suffered a stroke an have to type one handed.

Offline Stef.

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Re: !! I
« Reply #5 on: July 15, 2009, 02:18:21 PM »
5 contacts are only relevant if shooting with flash in ADI mode which is the preferred mode to TTL when it comes to the new generation of flashes. (More accurate)
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Offline gillymaggoch

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Re: !! I
« Reply #6 on: July 15, 2009, 09:44:56 PM »
So am I to ASSUME that if I buy another lens  even though it has only five contacts it should work in the auto focus mode ...
this lens isa sigma it says auto focus but it does not work in any othr mode than manual....Am I doing something wrong...have a wrong setting or something???

Offline Rob aka [minolta mad]

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Re: !! I
« Reply #7 on: July 15, 2009, 09:52:54 PM »
You are right to assume that a lens with 5 contacts will work in auto focus mode.

Which lens is it exactly that you have ???
And have you tried changing the focus selection to Continious or Single or Auto, assuming that its not on manual focus


Rob

Offline harveyzone

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Re: !! I
« Reply #8 on: July 15, 2009, 09:58:05 PM »
So am I to ASSUME that if I buy another lens  even though it has only five contacts it should work in the auto focus mode ...

Yep. Should work. The amount of contact will not be a factor.

this lens isa sigma it says auto focus but it does not work in any othr mode than manual....Am I doing something wrong...have a wrong setting or something???

What lens is it? It could be as simple as the contacts need cleaning, or the locating hole needs enlarging, it could be fixed by adding an aftermarket chip, or it may never be mendable!


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Offline Faldrax

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Re: !! I
« Reply #9 on: July 16, 2009, 10:09:58 AM »
There are two other possible reasons why AF would not work with a Sigma.

The worst case is that the lens is, in fact, broken, and has stripped AF gears - that should be fairly obvious as it will make a grinding noise when you try to focus. If this is the case, then you should get back in touch with the seller for a refund!

Alternatively, some older sigmas do not AF with the newer cameras. The reason is that Sigma reverse engineered the lens electronics to get AF working - so missed some bits that were not used at the time (bat are used by modern cameras).

You can get replacement chips for some lenses I believe.

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Offline gillymaggoch

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Re: !! I
« Reply #10 on: July 16, 2009, 02:20:57 PM »
THe lens is a SIgma  auto focus 60mm-200mm As indicated in a previous response...I have compared the "holes" and they appear to be of different sizes.. the one on the lens is considerably smaller..can this be enlarged without doing TOO much damage to the lens..
Thanks Jim

Offline harveyzone

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Re: !! I
« Reply #11 on: July 16, 2009, 04:42:53 PM »
THe lens is a SIgma  auto focus 60mm-200mm As indicated in a previous response...I have compared the "holes" and they appear to be of different sizes.. the one on the lens is considerably smaller..can this be enlarged without doing TOO much damage to the lens..

It is not a lens that I know of, but googling about, the only Sigma 60-200mm lens that I can find is a 60-200 F/4.5-5.6 AF-a. This is a very old push-pull zoom from the very early days of Minolta AF. I came across a seller reporting that theirs works OK on an A100. I have a similar 35-135 somewhere from about 1985 which I think worked on my A100 when I tried it, but that means nothing.

If the locator pin locates correctly with a nice click then you probably do not have to enlarge the hole even if it is smaller than on other lenses. If it does not push in correctly then the camera will probably report that no lens is attached.

I would start with cleaning the contacts with a pencil eraser and see if that helps. You could also try contacting Sigma and see if hey know of a compatibility problem. It is quite possible that you will never work on an A300.
« Last Edit: July 17, 2009, 04:23:42 PM by harveyzone »

Tom Harvey

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Sigma EF-530DG Super
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Offline gillymaggoch

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Re: !! I
« Reply #12 on: July 17, 2009, 02:18:34 PM »
I am going with the thought that this lens will not work with my 300..therefore the dealer on ebay will be put on my @~&%list and I will not deal with them again...thanks for your help  it is appreciated .
Jim

Offline winjeel

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Re: !! I
« Reply #13 on: July 17, 2009, 03:07:44 PM »
Before you do, have tried setting your camera to TTL, as Stef mentions that that may be an issue. And have set your focus mode to something other than was it is currently on?

I have an old Sigma, a pop zoom, a push-pull as Harvyzone calls it, and it works. So, if those don't work, then perhaps returning is a good idea. What sort of photography are you into, anyway? We have a list of great sites to look at when considering a new lens at this page here. Hope it helps.
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