100-300 , 50-500, TC, tele - please help

hi,

i want to buy a tele-zoom for my K100D.
i would like as much zoom as possible (animals & birds)
and i want to have fast focus !

important note, if AF or SR will not work in some cases, please point it, because i like to have them.

another important note, i looked at my pictures, and with the 50-200 i am using almost just the 200mm !!!
so this is the reason i want bigger zoom

currently i have 18-55 & 50-200 & TC tamron 1.4x

my thoughts were -

Sigma 100-300 F4,
this way i will have 100-300 with the best quality
with the TC 1.4 i will have a very good quality at 420mm F5.6 (i assume that TC will lower the quality),
people say that the SR will not work so good, because the camera doesn't know that i attached TC.

and now... lets talk about bigma (50-500 F4.0-6.3)
it's heavy ! i am afraid from it !
but 50-500mm... tempting

but if you will say that 100-300 is so much better, and with TC, it will still be better, then there is no issue.

please help...

thanks !

Shay

I have not actually used either, but from 100-300 my money would certainly be on the 100-300 as the better lens. Even with a 1.4x TC I would expect it to be at least as good, since a 1.4x TC isn't usually too bad quality wise. It's the 2x ones which really start to cause fun.


Now the bad bit,

If you get a modern TC (I suggest the Sigma EX one since you're getting a sigma lens) then AF will work. However, the TC doesn't change the focal length reported to the camera, so SR probably wont work that well.

It's possible that if you cover the 7th contact on the TC then you will be able to set focal length manually as you do with old lenses, not sure if that would work or what else might stop working though.

Pentax if you're reading this please can we have a "I am using a teleconverter" menu option in a future firmware? Surely it wouldn't be too hard to get the camera to multiply the reported FL by 1.4/1.7/2? Or at least could we have a "manual override" so we can set the FL manually?



There is another thing which I would consider. Pentax are about to release their first SDM lenses. Sigma like to reverse engineer things, so they can't do HSM in Pentax mount until they can get hold of a DA* lens to pull apart. I e-mailed Sigma a while ago and they said they hadn't heard anything from Japan about doing HSM PK lenses, but for my part I'll be giving it a few months before I spend big money on a long Sigma only to have them release an HSM version the next day.

Welcome to the forum


If you go down this road, do let us know how you get on. I have been toying with the idea myself - strictly for the birds of course

Comments on other sites aimed at bird watchers give it good reports - and think what a 1.4X would do to that

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Keep up the good work
Graham

I'll think of something someday.

I have the Bigma and love it. It is very good. I haven't tried it with a TC and you have to check it will work with yours as it doesn't work with all of them. I believe the Tamron one is Ok whereas the Sigma one, strangely enough gives problems.
The Bigma is tough to use handheld simply because of the weight of it, so you may have a struggle with it even with SR. But I see the 100-300 is only 300g lighter.

I also have a Tamron 28-300 which is also good, but I got the Bigma for the extra range it gives. It is not a walkabout lens though!

If you have a K100D I don't think it supports SDM/HSM anyway so you don't need to wait to see if Sigma eventually come out with one.

i will have to see them in real life,
because i simply cant decide between these two.

thanks,

Shay

you're right of course, my bad!

let us know which way you go Shayt, and how you get on. I think there are a few people around here eyeing up the Bigma and friends, I know I am.