[ripit]

That's exactly what I am looking for right now is a 28-70 (or similar) 2.8 constant aperture. That sigma is an auto focus lens right? If so, that's a steal (not sure what nikon mount goes for but for pentax that would be a steal). I have been looking for one in pentax and I'm expecting to have to pay at least 100$ for a decent manual focus one (I'll probably bide my time and look for a deal). Of course I have only been looking into them for a few weeks. One of the two lenses I mentioned that I got burned on was in fact a kalamar 35-70mm 2.8 constant. There is very little information on them but a couple claim that image quality is decent. Its the one that has the jammed zoom, corroded mount etc. I fixed the zoom (needs a clean and lube and I may or may not try to clean out the front glass). Honestly first impression is that the image quality is actually decent (very good for what it is considering it turned out to be a cheap Korean lens). The build quality is another store. I had to tear it completely apart and the workmanship and materials is kind of shoddy. With some more work, I think I might get it to last long enough to try out the 2.8 constant aperture at least. Its not worth the time to fight it out with this idiot to try and get anything out of him.
I have a vivitar 35-70 2.8-3.8 that is pretty good and I want to see if the constant apeture is worth the money (I suspect it will be).

Interesting about the lenses and prices variation.

You really have to know your product though when buying on ebay.

I did get a good lens for my Nikon (I shoot both Pentax & Nikon since I can rent Nikon lenses and Pentax lenses are virtually unavailable for rent) although I did pay $160 for it. A sigma 28-70 2.8 constant aperture. Only one other person was interested and I think it was because the description didn't really mention the f2.8, you had to look closely at the photos and it was advertised as a film camera lens. Luckily the seller had put up a lot of good photos so it was easy to verify mount and other details. Some people seem to think that you need special 'digital' lenses for digital cameras. It seems like a lot of money but from pricing them in other places they seem to run for about $250 and up. Being from the film age it's big & heavy and it great condition. Not a bargain like yours but one I'm very happy with and the seller was great to deal with. I asked him a couple of questions and he admitted he didn't know much about lenses and asked me to tell him what to look for. Someone like that I really like dealing with.

What I really want now is a matching lens for my Pentax, I keep looking but at the moment the sellers that have them know what they are and how much they should be going for.

Agree about the feedback when it's your fault. You lose some & you win some & hopefully the wins outnumber the loses. So far, they have for me on ebay.

[ripit]

I've bought and sold hundreds of ebay items. I just follow some simple rules.

Only buy from people who leave good descriptions, have actual photos of the item and have 99.5% or better feedback.

If the item isn't as described give the seller a chance to fix it. Mistakes happen but a good seller will make it good. If they don't then, well leave them a negative.

Mostly I've been selling lately and I've run into some real, er, "difficult" buyers. I have to grin and bear it, ebay heavily favors the buyer. I would say they're downright hostile to sellers these days.

The thing that sucks is that while some of those buyers are just jerks, some have probably been burned by others and it contributes to their attitude. I'm trying to avoid becoming one of them. I can understand that opinions of condition very and I can accept it not being as good as I thought. One big problem I have encountered is that they describe it as good condition or even go so far as to say it has good, clean or scratch free glass (I have even got no fungus on top of that). Then the lens arrives with glass so dirty you can not tell it condition much less see through the lens. About half have been excessively dirty. Luckily some cleaned up very nice (and some had fungus etc).

[mtansley]

That's exactly what I am looking for right now is a 28-70 (or similar) 2.8 constant aperture. That sigma is an auto focus lens right? If so, that's a steal (not sure what nikon mount goes for but for pentax that would be a steal).

The sigma is an autofocus and part of their older film EX line and an Aspherical lens. I'm glad you think it was a steal, that makes me feel better although I thought it must be worth something. Constant Aperture seems to add vast amounts to the price.

That's one advantage of having two systems, if you can't get it in one, you might find it in another mount.

[ripit]

There is nothing wrong with film lenses. All my autofocus lenses are full frame film lenses except the kit lens that came with my camera.
While with new lenses, constant aperture is a more expensive (harder and more expensive to build if I understand right), with used and in particular older MF used lenses, supply and demand has a lot to do with it. 28/35-80/90mm range zooms are perfect carry lenses and therefor popular (some want more on the wide end I gather). 2.8 is as fast as you are going to get in that range according to a few threads I have read. To go to 2.0 your front glass would have to be well over 100mm If I understand right. There also seems to be a very limited supply of constant aperture 2.8 lenses in this zoom range (both limited number of models made as well as a limited stock of used lenses out there) which is also going to kick the price way up. I got my vivitar 35-70mm 2.8-3.8 for 10$ plus shipping (pretty sure it was about 20$ shipped) with a working? pentax p3 film camera. When searching for constant aperture ones in this range I have found lots of ones that are 2.8-? variable aperture and they are a lot cheaper (supply and demand I guess). In demand + low availability + fast + constant aperture = $$$$$$$ I guess

Longer zooms with constant aperture and not super fast are a dime a dozen. I just got a MF vivitar 90-230mm 4.5 with a jcpenny 80-200mm 4.5 thrown in for free for 5.99 shipped. I asked about combined shipping 30 minutes before auction end and didn't get a response in time. I only bid on and won the vivitar. The seller messaged me and asked what else I was interested in. I said the jcpenney and she threw it in for free. Of course the jcpenny was minolta mount so worthless unless I rip the mount off and install a modified mount). The vivitar was t4 mount (can be adapted to m42 if I can find a t4 adapter cheap enough). I of course gambled on what mounts those were (not a total loss on the t4 as it can be adapted). Thats my worst mistake on mount gambeling but 5.99 for 2 lenses? Not a big gamble. vivitar 70-150mm 3.8 seem to be very common and cheaper too. There is one buy it now for 60$ but I bet you could get it for half that or less on an auction.

[InlawBiker]

You make good points, but I think you over-analyse. You shouldn't worry about things you can't control. Perhaps some buyers have been burned in the past and perhaps not... the only thing that matters is whether the item you bought in that one auction was accurately described.

If it was - great! Mark them positive. If not then send them a note and ask them to fix it. If they don't then press for a refund or give them a negative remark.

I think you're trying to be too nice. Some sellers really are dishonest - you should get your money back AND mark them negative. That's the responsible thing to do.

Greg.

The thing that sucks is that while some of those buyers are just jerks, some have probably been burned by others and it contributes to their attitude. I'm trying to avoid becoming one of them. I can understand that opinions of condition very and I can accept it not being as good as I thought. One big problem I have encountered is that they describe it as good condition or even go so far as to say it has good, clean or scratch free glass (I have even got no fungus on top of that). Then the lens arrives with glass so dirty you can not tell it condition much less see through the lens. About half have been excessively dirty. Luckily some cleaned up very nice (and some had fungus etc).

[ripit]

You make good points, but I think you over-analyse. You shouldn't worry about things you can't control. Perhaps some buyers have been burned in the past and perhaps not... the only thing that matters is whether the item you bought in that one auction was accurately described.

If it was - great! Mark them positive. If not then send them a note and ask them to fix it. If they don't then press for a refund or give them a negative remark.

I think you're trying to be too nice. Some sellers really are dishonest - you should get your money back AND mark them negative. That's the responsible thing to do.

Greg.

Thats all good advice. With all the junk lenses out there (after all, its old and there are going to be bad ones), being too nice or forgiving isn't going to help me or the next person that buys from them.