EBAY - 50mm K lens / should we all have one?!

Hello all.

Firstly, thanks to all for the wonderful advice I've received from this forum. As a relative newbie with K20D & 18-250 lens (Xmas), I have a lot of learning ahead of me yet!

I've been watching the auction of Pentax lenses (old & new) on Ebay over the past few days, and I'm interested in buying a 50mm f1.4 lens.

A company trading as Ameliaarts is selling a heck of a lot of old Pentax gear.

1st question: should I buy an old 50mm f1.4 lens, or pay the extra for a new lens from SRS?

2nd question: presumably the old lens would fit (K lens) the K20D, albeit I'd not have the Autofocus available to me...is this assumption correct?

3rd question: these old 50mm lenses do look as though they were well built. How does the quality compare to contemporary smc FA 50mm f1.4 lens?

4th question: there actually seems to be a glut of 50mm f1.7 (as opposed to f1.4) lenses for sale on Ebay from Ameliaarts. Were these lenses really so popular, or simply does nobody want them?

5th question: in terms of performance, is there a great diffence between the f1.4 & F1.7 lenses?

I can think of many more questions, but I'd best stop here for the moment!

I've not posted to the forum for about a month (very busy at work), so it's nice to the back...been reading the wonderful entries in the forum recently about flash photography...still try to understand that too, but for the moment my praises and thanks to MatMatic for the tremendoes work you've done here.

Regards to all.

Alan Lowe-Jones.
Cheshire.

1) Either will do very well, provided the used one is in mint condition.
2) Yes. Use A series or later lenses for most convenience.
3) Exactly the same.
4) At one time all new cameras tended to be supplied with 50mm lenses, so there are lots of them about.
5) The f1.7 will be better if you want to use it close up for document copying and to generally abuse it with add on lenses or extension tubes. The f1.4 will be better for low light work. But the difference generally will be minimal.

Hope that helps!

1. I suggest an a second-hand A 1.7 to save money, or a new FA 1.4 for the convenience of auto focus.

2. No AF and also no auto exposure with K and M lenses. Manual mode is required and metering doesn't work properly without manual compensation as well. The A series (with an "A" on the aperture ring) provides auto exposure so that you can fully use the camera's auto and semi-auto modes.

3. The build qualty of K, M and A lenses is excellent, with a lovely manual focus action, and the optics are the same as more modern ones in some cases as well (but not always).

4. The 1.7 lenses were made in large numbers and were often supplied with cameras, hence the glut now. It's one of those rare combinations: cheap AND good.

5. The differences are subtle. I have one of each and would need to do a careful test to pin down real differences in image quality (which I haven't done).

1. The old 50mm M and A Lenses are manual focus whereas the new 50mm FA Lens is autofocus. The old 50mm M Lenses will only work with manual metering mode on the K20D. The old 50mm A Lenses will work in all modes (although no autofocus) if the A position of the lens aperture ring is selected.

2. Yes 50mm M and A lenses will fit your K20D.

3. The optics are very similar between old and new 50mm designs.

4. The 50mm F1.7 lens was supplied as the normal kit lens with very popular Pentax ME Supers etc.

5. I believe that the 50mm F1.7 and 50mm 1.4 Lenses are both very good in optical performance.

If you want to try out a 50mm lens, I have a Jessops 50mm f1.8 version for sale @ £10+ p&p. Which for not a lot of money you can have a play with and see what you think.

I have used it quite a bit, but now its surplus to my requirements.
It is a manual version only, but optically its unmarked and produces sharp results.

You have to set the custom menu on the K20 to use manual aperture, I think then you can use the green button to get your exposure setting, based on the green button custom setting for priority (eg shutter or aperture). I just use a light meter and check the exposure, retaking if necessary.

Have a look here

Example image taken with this lens on a K20

My thanks, John, Pete & Graham.

That info has been a help, especially the business of the 'A' for auto exposure.

Also good to read that there's not a great deal between the 1.4 & 1.7 lens. I've probably just opened a can of worms with a statement as controvertial as that!

I guess I have to make up my mind and pay my money!

John, one quick question: I recently met a chap called Paul Jones at work here in Golborne (East Lancs road). He's a member of the Atherton Photographic Society. He mentioned the club had its own great Pentax advocate called John. I'm guessing this is your own good self?

Many thanks to all.

Alan Lowe-Jones.

Not guilty, must be another John

Have bought a few items off this company, delivery is very fast and items well packed.
Would reccomend them.

Hi jon.dc

Thanks for offering this lens, and to be honest, it will be a good start for me where the 50mm lens is concerned. So, yes please, can we arrange for the sale.

Is there a protocol which we follow in the forum for transactions, or do we simply plough ahead and exchange details?

Many thanks.

Alan Lowe-Jones.

Many thanks, davex.

It's good to know that they're geniune.

Much appreciated.

Alan.

On the differences between 1.4 and 1.7 versions; I've had a few of each pass through my hands now and (without backing it up with anything like serious testing) I have the distinct feeling that the 1.7 versions are sharper from wide open up to around f2.8 where the two are about even, then the 1.4 versions tend to be better performers from f4 downwards. By better I mean they are equally sharp but the 1.4s just seem to produce a "nicer" picture somehow - hard to put my finger on exactly why.

As I only use mine for low-light handheld work then it's the "wide-open-quality" that interests me the most; hence my keeper is an M50/1.7 rather than the 1.4, even though the latter allows for an extra half stop of speed.

I don't think you'd go too far wrong with either though.

That would be me.

Thanks, hefty1.

That's a brilliant summing-up of these 50mm lenses. My purpose in buying one is to address low-light portrait situations, so the wide-open quality and sharpness at this stop is important to me too.

Many thanks.

Alan Lowe-Jones.

pm sent

I took the plunge and bought the 50mm A F1.7 last weekend from Ebay. It arrived today. Looks very nice and works a treat. Been photographing freshly baked flapjack with it and thoroughly annoying my wife.
Boy is it good for low light and so sharp.
This is the seller i used:

link

Can certainly recommend him now.

Russ