[northcoastgreg]

FA24-90 3.5-4.5 might be another option.

The FA 24-90 features a very loose focusing ring, just like nearly all Pentax non-star AF zooms. Optically, it's a nice lens, at least as far as contrast, color and rendering go. In terms of edge to edge sharpness, it has serious issues, particularly at the wide end, even on APS-C. But most non-star Pentax zooms have issues of some sort (which is why I'm not a huge of fan of using old zooms on what will presumably be a $2,500 camera).

[From1980]

Any experience with third-party options?

My favorite third-party lens line has always been Tokina and years back the ATX Tokina line was particularly well built, usually a cut above in sharpness and contrast, and often fast max aperture. Some are favorably reviewed here on PF third party lens database.

[pathdoc]

which is why I'm not a huge of fan of using old zooms on what will presumably be a $2,500 camera

Buying the K-1 solely to plant upon it a second-hand kit zoom I paid a pittance for would be criminal, I agree. But for me it will be 90% about the primes, and until Pentax comes out with a full-frame D-FA zoom that isn't hideously huge and hideously expensive for speed I don't need, I'll be quite content to put older, lightweight zooms on it for casual uncropped shooting. For crop mode zoom shooting I am well equipped, including WR.

[northcoastgreg]

But for me it will be 90% about the primes

Why not make the FF 100% for primes and keep an APS-C camera for zooms? Even a lens like the DA 18-135, shot on APS-C, will likely out perform (at least in terms of color and contrast) most of the old non-star film era zooms.

until Pentax comes out with a full-frame D-FA zoom that isn't hideously huge and hideously expensive for speed I don't need

The slower "kit" zoom might turn out to be the only lens that ever comes close to fitting this description. And while it would not be a "pro" lens, it'll likely be much better than the kit lenses of old (i.e., more in line, quality and price-wise, with the current Sony 28-70 and Nikkor 24-85 than the old F/FA 28-80's).

Also keep in mind that if Pentax ever did get around to making a pro-quality f4 standard zoom, that it would likely cost over $1,000 and weigh at least a pound and half. (The Canon 24-105 weighs a pound and a half and costs ~$1,000 --- and it's an older lens. I could easily see a Canon 24-105 II having an MSRP over $1,400.)

[pathdoc]

Why not make the FF 100% for primes and keep an APS-C camera for zooms?

Because I am lining up the full-frame to replace my K-5 when it dies, just as the K-5 replaced my *ist-DL.

Even a lens like the DA 18-135, shot on APS-C, will likely out perform (at least in terms of color and contrast) most of the old non-star film era zooms.

This, I do not doubt.

The slower "kit" zoom might turn out to be the only lens that ever comes close to fitting this description.

It will be interesting to see exactly what the K-1 comes out with glued to its front at the budget level. Unless they surprise us by releasing the 21st Century full-frame kit zoom with the camera (perhaps the reason for the delays?), my guess is the 16-85 as sort of a "premium kit lens" for those who can't afford it with the D-FA 24-70/2.8. The 18-135 was definitely not a "kit" lens when it came out, but discounts on it ever since have been pushing it ever closer to being regarded as such, and I think it has also been offered as part of some APS-C bundles; Ricoh Marketing might decide that it's too common and humdrum a lens to put on the front of their brand new pride and joy.

Of course they may just ship it with a body cap. Or go full-on old-school and put an FA50/1.4 on it. But I actually don't think it would be all that hard to build a consumer-grade kit zoom that was constant f/4, and the extra stop at the long end might well win it a few friends. I'm sure they did all sorts of parametric CAD studies when they were designing (or rather reverse-engineering and Pentaxifying) the D-FA24-70, and they must have at least ballpark figures for how much size and weight they can shave off by sacrificing 4mm at the long end, losing a full stop over the entire range, etc. etc. And thanks to their experience with the Limiteds, Pentax are the experts when it comes to size and weight reduction.

[gofour3]

This is about potentially replacing a lens in the 28-35 to 70-80mm range, so let's keep things on topic.

The SMC Pentax-M 24-50mm F4 and SMC Pentax-M 28-50mm F3.5-4.5 are another decent option for less than $100.00.

Phil.

PS I have an extra SMC Pentax-M 28-50mm F3.5-4.5 if you are interested, PM me.

[Just1MoreDave]

...A35-70/4.0 looks significantly lighter, and for the constant f4 I could live with the half-stop loss at the short end to keep half a stop at the long.

Ultimately it would all depend on whether I found one in the flesh and how it felt on the camera.

Any experience with third-party options?

I had a cheap Sigma 35-70/f3.5-4.5 lens with a KA mount that was fine with my P3n. I knew it wasn't great but I liked the zoom range. There is a faster Sigma, f2.8 to f4, but Sigma coatings of the era were clearly not as good as Pentax. About 8 years ago I got an A35-70/4 and an A35-70/f3.5-4.5. The second lens is optically the same as the F version that is very popular on a DSLR. It felt a little cheap to me, not as bad as an AF lens for manual focusing. It's a one-touch zoom. I liked the A35-70/4 a lot better. It felt like a higher quality lens. It has separate zoom and focus rings. It uses a 58mm filter. Except for the two-touch zoom, it's much like the A70-210/4 and would make a good pair, sharing constant aperture and filter size.

I kept the A35-70/4 to use on the P3n but never wanted to go back to film. I can't find it today, don't remember using it or selling it or what drawer it might be in.

[pathdoc]

I kept the A35-70/4 to use on the P3n but never wanted to go back to film. I can't find it today, don't remember using it or selling it or what drawer it might be in.

It's probably hanging around with my SMC-A 50mm f/1.7, which I was sure I kept when the P50 it came with died, but which mysteriously disappeared when I moved from Australia to Canada. I'm sure the next time we move house, it will turn up. I bought the DA50/1.8 to replace it and BANG, straight into the LBA rabbit hole I fell.

[funlw65]

Film era K-mount zoom lenses to potentially fill a gap.

Now, this is a problem! Bye-bye the best source of cheap but good FF lenses. When the K-1 will hit the market the advantage over the Nikon F-mount will be lost.
Well, back to the M42 lenses...

Of course, not many of the lenses will pass the test but that won't stop the price increase. And Samyang lenses are the best among "everything manual" breed.
I'm talking from a film user perspective.

[blende8]

On my MX I had the Tokina 3,5-4,5/28-70 which has the A-setting.
It was a good lens.

A very good, but rare lens of that aera is the Tokina 2.8/60-120.
I once owned it and was very pleased with it, but sold it, when I gave up film.

One of the better AF lenses is the FA 3.2-4.5 / 28-105.

[pathdoc]

Of course, not many of the lenses will pass the test

And you know what that means... SOLD, to those who are happy with something less than being able to count the nose hairs on a squirrel at 1000 yards at ten thousand percent crop in the corner of the frame.

Don't worry - the time of the Cheap Secondhand Pentax Lens Drought will be brief.