Still not decided on which DSLR but question about lenses

[cirks]

For those that were kind enough to offer advice to my original posting about which DSLR to go for (and things to think about when choosing), the update is that I am not really that much closer to making a decision (haven't had time to go to shop and play with them properly) but have been reading as many reviews as I can. All this has confirmed is that some people and magazines think the D50 is best, some the KM D5, some the 350D and a few the Pentax *ist. Hope to try some of them this weekend and see which one I am happiest with.

However, I have 2 questions regarding lenses:
1) the AF lenses I have for the Minolta SPXi film SLR I have are both Sigma. Although they are getting on a bit (I inherited the camera and lenses so don't know how old they are except definately > 7 years) are they really likely to be any worse than current sigma lenses of the same spec? [35-70AF and 70-210AF).

2) Obviously companies such as Sigma, Tamron, Tokina etc make lenses with different mounts for Canon, Pentax, Nikon etc but are the mounts replaceable? ie. if you owned Nikon mounted Sigma's, is it possible to just get the mount changed to a Canon one etc?

The 1st question arises because as most of you have said, the current DSLR bodies will become 'disposable' items and therefore it is the lenses that will form the long lasting basis of a digital camera kit. Therefore, [b]if[/b] I were to stay with KM and go for the Dynax D5 or D7 and use my existing Sigma lenses, would I still have as good a system as D5 with a new 35-70 Sigma etc?

Sorry for the diatribe...

[cirks]

no thoughts then?

[simpo two]

cirks said:

All this has confirmed is that some people and magazines think the D50 is best, some the KM D5, some the 350D and a few the Pentax *ist.

cirks said:

However, I have 2 questions regarding lenses: 1) the AF lenses I have for the Minolta SPXi film SLR I have are both Sigma. Although they are getting on a bit (I inherited the camera and lenses so don't know how old they are except definately > 7 years) are they really likely to be any worse than current sigma lenses of the same spec? [35-70AF and 70-210AF).

Sometimes products improve with time, sometimes they don't (witness Vivitar). If you were happy with their quality on the SPXi, I don't see a problem on that score - BUT make sure they will support all the various functions on a Minolta DSLR.

cirks said:

Obviously companies such as Sigma, Tamron, Tokina etc make lenses with different mounts for Canon, Pentax, Nikon etc but are the mounts replaceable? ie. if you owned Nikon mounted Sigma's, is it possible to just get the mount changed to a Canon one etc?

I don't know, but the gubbins in lenses is so much more complex since the days of the Tamron Adaptall 2 mount or Series 7 jobbies that I fear it's unlikely. It's more than just the physical fit of the bayonet; the AF, metering and position/number of contacts all have to be considered. For a definitive answer, why not mail Sigma and ask?