[thibs]

As long as there's a way to automatically shutnoff camera SR when an SR lens is used, it looks fine to me.

[Rondec]

As long as there's a way to automatically shutnoff camera SR when an SR lens is used, it looks fine to me.

I think it should either work with the in body shake reduction (I think Olympus has done this) or shut of the in body shake reduction. The biggest benefit of SR in the lens is having a stabilized viewfinder, which can be really nice.

[Smolk]

Pentax has spent 12+ years building its reputation as a value-oriented brand, partly because one pays up-front, one time, for SR in the body.

Indeed, there's no reason for that to change. Also, lens SR would make the lens larger, and there is a market for less large lenses too.
Large lenses for optimum quality, there's room for that, but there is always a limit.
Is anyone using the 645 FA 400mm on a K-1? You'd loose the AF of course, but the lens seems worth it.

[Serkevan]

Indeed, there's no reason for that to change. Also, lens SR would make the lens larger, and there is a market for less large lenses too.

The weight of the in-lens stabilizer for a tele lens is ~40 g (The Tamron 70-210/4 is listed at 859 g in EF/F mounts (however Amazon lists 1.87 lbs comes out to 848 g?) and 1.81 lbs / 819 g for the Pentax. The old Canon EF 70-200 f/4L also has a ~35 g increase when going to the IS version (but I'm not 100% sure the optics are exactly the same, and I think the IS version has more weather sealing).

All in all it shouldn't change too much for a lens with less glass. For example there are Canikon 18-55 kit lenses with IS (198 g for two Canon, 195 g for Nikon), that are a bit lighter than the Pentax (220 g for the non-WR AL ii) one. All three with 11 elements in 8 groups.

[wkraus]

Is anyone using the 645 FA 400mm on a K-1? You'd loose the AF of course, but the lens seems worth it.

I do (every now and then) – a fine lens even on the smaller sensor, but difficult to focus with its rather short focus throw.

[loyalt]

Still wanting and needing either a 300mm f2.8 or a 400mm f2.8

[zapp]

If you need 2.8/400, this is the wrong brand. 2.8/300 is not impossible, but may take some Timecode surface.

[reh321]

Still wanting and needing either a 300mm f2.8 or a 400mm f2.8

Why do you want f/2.8 on those lengths?
From what I see, you get plenty bokeh with "slower" lenses, and the Pentax solution for having less light seems to be graceful higher ISO performance.

[Smolk]

Why do you want f/2.8 on those lengths?
From what I see, you get plenty bokeh with "slower" lenses, and the Pentax solution for having less light seems to be graceful higher ISO performance.

A very straightforward reason could be the use of a 2x teleconverter, which makes it 5.6 wide open, perhaps 11 at highest IQ.

[bertwert]

Why do you want f/2.8 on those lengths?
From what I see, you get plenty bokeh with "slower" lenses, and the Pentax solution for having less light seems to be graceful higher ISO performance.

Please show my a photograph with your "77-420mm f6.3-9 PLM" that you keep going on about being more than anyone ever needs that has similar qualities to say this shot with a 300mm f2.8:

Speaking of 300/2.8...

I agree that a 400/2.8 is getting excessive and more than many users would need or ever be able to pay for, but a 300/2.8 is quite a useful lens, especially in wildlife and sports contexts.

[reh321]

Please show my a photograph with your "77-420mm f6.3-9 PLM" that you keep going on about being more than anyone ever needs that has similar qualities to say this shot with a 300mm f2.8:

I agree that a 400/2.8 is getting excessive and more than many users would need or ever be able to pay for, but a 300/2.8 is quite a useful lens, especially in wildlife and sports contexts.

I have displayed them - which is why I know what the bokeh is like.

My question is how many 300mm f/2.8 lenses would Pentax actually sell.
I would certainly never spend my money on one, because I would often have to lug one for a mile more to use it.
Maybe you will see things differently in another fifty years - after you have retired {which will come after you graduate from college}.

[luftfluss]

I have displayed them - which is why I know what the bokeh is like.

My question is how many 300mm f/2.8 lenses would Pentax actually sell.
I would certainly never spend my money on one, because I would often have to lug one for a mile more to use it.
Maybe you will see things differently in another fifty years - after you have retired {which will come after you graduate from college}.

Remember the old expression, "there's no substitute for cubic inches"? Aperture is like that... at least until "computational photography" figures it out.

I've owned the 55-300 PLM, and it is nice for what it is, but it cannot resolve the fine detail that even my quarter century old 300/2.8 and 400/4 can. It's just not what the 55-300 PLM is designed to do.

If you check out fredmiranda.com, which is one of the Internet's most popular photography sites - as opposed to a photographic gear site like DPReview - the most popular photographic genre there is wildlife, with about 25% more action than landscape. And a large chunk of those folks are shooting 400/4, 500/4, 600/4 lenses. Folks are willing to sink serious money and tote heavy lenses and get up hours before dawn and lay down in the mud to get their photos. This is an area of growth for the camera industry.

The Olympus 150-400/4.5 is heavy by m4/3 standards (1.8kg) and expensive @ $7500. There's been a waiting list of over a year for it.

300/2.8 feels a bit short, particularly on full frame, unless Pentax also released FF-compatible teleconverters along with it. 400/4 would be nice, and of similar size & weight to the current D FA 150-450. In addition to being brighter than the 150-450, it would also likely have faster AF. And DSLR's are a bit more dependent on aperture size for AF speed than mirrorless cameras are.

[bertwert]

Maybe you will see things differently in another fifty years - after you have retired {which will come after you graduate from college}.

I hadn't considered retiring before I graduated... anyways, in 50 years time, the word "retirement" will be marked as archaic in the dictionary because the cost of living will have raised exponentially above any wages, and all us (currently) young folks will be working until we drop dead

[TwoUptons]

I hadn't considered retiring before I graduated... anyways, in 50 years time, the word "retirement" will be marked as archaic in the dictionary because the cost of living will have raised exponentially above any wages, and all us (currently) young folks will be working until we drop dead

It isn't just you young folks who may not retire in the traditional sense

I'm just glad photography is cheaper than classic cars...

A 400 f4 does sound like it would be cool, but even a modern AF replacement for my 400 f5.6 would be neat.
But I don't see either of those happening with the 150-450 being a modern choice.

-Eric

[reh321]

I hadn't considered retiring before I graduated... anyways, in 50 years time, the word "retirement" will be marked as archaic in the dictionary because the cost of living will have raised exponentially above any wages, and all us (currently) young folks will be working until we drop dead

In my 30s, 40's and 50's, I kept saying I would put off retirement until I was 70.
Then, when I was 65, my wife {who is younger} found employment close to where my parents lived.
After a futile year, I listed my status at Linked-In as "I guess I am retired".
My wife had a 'heath crisis' when she was 66, and her employer decided that it was time for her to retire ..... just in time for her to avoid having to deal with Covid.