older Prime vs newer Zoom

OK I have a hankering to get a 24mm Sigma miniwide, or a 28mm Pentax A. I like prime lenses. I'm looking sub £100 older primes.

However, frugal me thinks the Tamron 17-50mm I already have on the front of the camera is not a bad performer.

I'm not bothered about manual focus or size as I'll be carrying the 17-50mm around with me all the time.

Purely on IQ what are the experiences of the forum about whether the expense gives a good return in IQ over the likes of a decent zoom.

I would think the best of modern zooms would give better IQ over all but the very best of the 'classic primes'. What you gain, usually, is speed, size and weight, and the pleasure of using nicely made older glass. And this is from someone who has lots of older glass and loves using it...

K.

Unfortunately, I don't have a "best of" modern zoom with which to compare, but I do have three sub £100 primes that definitely out-perform a Pentax 18-55mm ALII kit lens - though I couldn't guess how they would compare with a Tamron 17-50mm.

You could do worse than have a look at the Sigma 24mm f2.8 Superwide II, which is very sharp and rarely parted company with my K200D for months after I bought one about 18 months back.

A couple of others that equal the performance of the Sigma and outperform the kit lens are the Chinon 28mm f2.8 and XR Rikenon 50mm f1.7 - though you'll probably get mixed views about those from some forum members. Having said that, you'll pick up either for about £20 on Ebay, so your risk isn't that great.

I know that many don't have much time for test charts, but I find that the lens test chart given away recently in Amateur Photographer is a useful tool for comparing the resolution of lenses in a repeatable way (providing your shots of it fill a quarter of the frame and not the whole frame). I've briefly and not very scientifically compared five lenses recently with it - the kit, the three primes mentioned above and also a Kenlock 28mm f2.8 which I picked up on Ebay for little money. The Kenlock didn't come out too well, so I'd be tempted to avoid it.

Best of luck in your search.

Andrew

I've got the Chinon 28mm f2.8 and it's a handy lens for close-ups from 200mm and can have nice bokeh and character. It's really soft though at the edges and corners, making it unusable for things like landscapes and buildings.

If you have the Tamron, I doubt many MF primes could give it a kicking on IQ alone. I think they make more sense if you can't afford to buy something like the Tamron but need something a bit better/faster than the kit lens. Or if you just want the enjoyment of using a small, light, unobtrusive prime. Some primes have special qualities, such as unique bokeh or colour rendering. I bought a 20mm recently, and it does seem to have it's own character, unless it's just my imagination. I don't need to check if it's as sharp as the Tamron. I know it probably won't be.

How is the Tamron wide open, surely some primes will be better then that lens at f/2.8 or not?

I have a Vivitar(komine) 28mm f2.8 - I like it a lot but would not expect it to outperform the 17 - 50 tamron but given the price difference (under £30 for the viv) I reckon the vivitar does well given the price

I bought the Chinon only a few months back and it was almost permanently on the K200D during our recent holiday in Scotland. I've just had a quick squint at several shots taken and cannot see any significant tendency to softness at edges or corners. It is very usable for landscapes. You might have a bad sample.

Andrew

Could be Andrew, but all my 28mm are soft at the edge apart from the Ensinor which cost a small fortune ..... £5 Mint in box

The Tamron is very sharp at 2.8, for a zoom lens. The Sigma 24 might just edge it, I'm not sure.

I am tending towards the Sigma 24mm II, any other candidates?

Well I got a PK-M 20mm f4 for just within your budget recently. Really enjoying it although the reason it was cheap was that it was scratched

So I think the Sigma 24II is along the right lines as an inexpensive pocket street lens. Here's one that shows the sharpness at f2.8.

New AFL zooms for when you're in a hurry.
Old AFL primes for when you have more time.
And older glass has more 'character' (flaws).

Didn't HCB say, "Sharpness is a bourgeois conceit" ??

there are some members here who would make a sun king blush they rate sharpness so highly.

( wrong Louis. I mean 16, spouse that Antoinette bint) You get the drift.

This is a 100% crop of the extreme bottom left corner of a photo of Glenuig Bay (might not even have been in focus, as the grass was entirely incidental to the photo).




I'm sure I could find much better examples, but I don't think this suggests that the Chinon (£15 not in box) is "unusable for things like landscapes".

More incidental grass - 100% crop of bottom left corner of a photo of a beach at Muasdale on Kintyre - but taken with a Sigma 24mm f2.8 Superwide II




Andrew