Lenses:
Four thirds 40-150mm f3.5-4.5
Micro four thirds 40-150mm f4.0-5.6

I'm looking to add a few lenses to my bleak OM-D system, I currently only have a legacy Fujinon 55mm and the 12-50mm kit lens, I'm looking to grab the 45mm f1.8 at some point, along with a wide'ish pancake (12mm f2.0 Zuiko is too expensive!) and telephoto lens, I thought I'd start with varying my focal length and go for the telephoto first which should completely cover my range, then I can get into different apertures once I can afford them.

My budget is £110 and I've found a few in that range, I'm mainly looking at the 40-150mm Olympus lenses, the old 4/3 lens and the newer m4/3 lens, but I cannot choose between them, the older one would need an adapter but that remains in my budget (£70 for the lens, £40 for the adapter) just fine, where as the newer, slower one is £105 used.

My preferences are aperture and image quality, the old one has a bigger aperture (f3.5-4.5) than the newer one (f4.0-5.6) which is already a good start, however I'm mostly worried about the image quality being worse, with it being an older 4/3 lens.
Size isn't much of an issuel, going by dimensions they're both fairly close (older being a bit bigger) and would both fit nicely in my camera bag and wouldn't be much of an issue, I also wanted to know if either of the lenses supported the OM-Ds IBIS for video, which would be a nice bonus if a zoom video is required.

Thankyou for any replies, all the best.

They're essentially the same lens. The new one has been revised to AF dramatically faster on m4/3 bodies, which will probably be useful to you and there's no sense in paying extra for the old one unless you really want the adapter for something else. The aperture difference is trivial.

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Olympus E-M5, Sony A65, lenses.

I had the original one and traded it because it was too slow.
I tried the new version in a store last week, and it was night and day on the AF.

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E-PL1
X-E1
X100
E-PM1
http://www.flickriver.com/photos/13969659@N04/

It does seem like the new 40-150 which is native m43 would be the better choice then, can anyone confirm if the OM-Ds IBIS supports it for video?

Thankyou.

F3.5 vs. F4 is no big deal. I rather have a sharp F4 image than a soft F3.5.

It's a really good time to pickup a Panasonic 14mm on eBay. That's how I got mine and the shipping was quick to Canada. Seller marked package as gift so no delays at the custom.

I've been looking towards the olympus pancake because of the IBIS compatability for video, the pana doesn't have it does it?

For video you want a lens that has silent focusing. Any Olympus lenses marked MSC would be suitable. Panasonic lenses that are silent focusing are also plentiful, however it's not something advertised with an abbreviation. You kind read the lens reviews and find out. As far as I know the 14mm pancake focuses silently, you should Google for a review.

IBIS works on any native lens. Doesn't matter what brand.

To be honest the best video lenses are the power zooms, such as the 12-50mm that you already have. It makes the zooming a natural experience.

Oh I didn't know that, I could have sworn that only certain Olympus lenses worked with the OM-Ds IBIS for video, so any m43 native lens (with those pin things) will work with IBIS for video? I think I'll have to grab the panasonic if that's the case.

What about lenses such as the 40-150mm 4/3 with the adapter that allows for auto focus (electrical adapter such as the MMF-2), would that be compatible with the OM-Ds video IBIS or does it have to be a completely native m43 lens? Thankyou for the information.

Pretty sure any legacy lens would not work with IBIS in video mode. Doesn't matter which adapter you used.

And yeah when I say native, must have electrical contacts at the lens mount. So the Voigtlander 25mm F0.95 won't work with IBIS in video mode, even though it's a m4/3 mount. It's missing the electrical contacts.

Big but here. IBIS works with any lens in still mode. As far as I know. Some Googling may correct m if I'm wrong.

Yes the IBIS does work with any lens in stills mode, makes for some easy manual focusing with magnification if you have the camera use IBIS whilst the shutter is half pressed.

I feel I'm beating a dead horse here, but the 4/3 lenses won't be compatible with the IBIS for video even though it has the electrical contacts that go through the adapter into the camera?