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07-15-2021, 08:17 PM   #1
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Practical Impacts of new K3-III capabilities on Lens Selection - Coatings & Apertures

We are liquidating our FF glass FA* 24, 28-80, 300FA*/2.8 and DC 12-24/4, DC 18/135wr, FA 50/1/4, DFA 15-30, 24-70, Sig 150-500 DG-OS USM.

Keeping/ bought- DA*11-18, HD16-50PLM, DA*60-250/4 SDM, DFA100macro/2.8wr, SMCDA10-17FE, DA*300/4, DFA* 70-200/2.8 and a 500mm Tamron mirror.

Question driving the conversion/ purge.... Whether by dynamic range or other sensor driven capability, is the K-3 III good enough to move to smaller aperture/APSc glass... Will the drop from a 300mm /2.8 crimp us when we use 300/4?

We can see the effects of coatings on the bench. We can see lens speed in the wild.

Is anyone else resetting their kit? Will the 1 stop loss on F4 vs f2.8 glass be missed with such amazing new capabilities?

We'd love your thoughts... THX

Last edited by GlassJunkie; 07-16-2021 at 12:07 PM.
07-15-2021, 11:38 PM - 1 Like   #2

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For me, the better OVF and the more accurate AF have seen an increase in wide open use of my current lenses. On previous Pentax APS-C flagship bodies, wide open meant using LiveView to get an accurate result, whereas now I'm pretty confident the camera is nailing the AF where I want it to be. In my current kit that applies to lenses that are mostly FF, i.e. the FA limiteds and some older manual glass. So I will rather be increasing my use of FF lenses.

On the APS-C lens front this means the new PLM DA*16-50/2.8, which seems an excellent f/2.8 performer, becomes more certain to be added to my kit to replace the SDM DA*16-50/2.8 which was never great wide open.
07-16-2021, 12:30 AM - 1 Like   #3

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The a/f performance of the K-3iii is enhanced at f/2.8, so restricting yourself to anything smaller, especially if you already have the option, could be counter-productive. Whilst the subject tracking especially is superior to previous models at any aperture, in my experience, my only "fast" a/f lens, an old Sigma 70-200mm f/2.8, really shines on the K-3iii. I'll certainly be looking for something a bit longer as soon as the budget allows
So, if you're subject matter is likely to include moving subjects, I'd suggest keeping the fast glass, even if you only use it when needed. Other than that, the low-light capabilities of the K-3iii are really very good, so a slower lens is unlikely to be a restriction under normal circumstances where depth-of-field isn't a consideration.
Do note, older glass, especially wide aperture older glass, may well benefit from the judicious application of the a/f Fine Adjustment feature … this of course being true for older cameras as well as the latest!

Last edited by kypfer; 07-16-2021 at 12:37 AM. Reason: Afterthought
07-16-2021, 02:20 AM   #4

Seems a shame to get rid of the FF lenses; I've found they work just as well on APS-C, so I've only got a couple of APS-C lenses, and routinely use FF lenses on the KP. On the one hand, it's a waste for all that light coming in that won't hit the sensor; on the other, you can't sell used lenses for an amount of money that really represents their true value, which means if you sell them at a loss, you've wasted your money. The only way you're going to get your money's worth out of a lens will be to use it. I don't have or use most of the lenses you've listed, but those I do have are terrific lenses. Why not at least identify some favorites and only liquidate the ones you never actually use?

By the way, I certainly approve the purchase of the DA*11-18 - that's one of my sharpest, and worth having just because it's a terrific lens. As is the 100mm macro, but you know that's an FF lens, right? And I'd certainly keep the 300mm. The use of focal length to describe a lens is somewhat anachronistic, all that really matters is the angle of view a lens will give you on a particular camera, and any 300mm lens is still a 300mm lens on any camera. And whether the crop factor of an APS-C lens is restricting the light received or the outer circle of that received with an FF lens makes no difference in defining what light hits the sensor. Either 300mm lens will give you a viewing angle of 5.4 on the APS-C camera, I think. I'd keep the faster lens, myself.

Last edited by dlhawes; 07-16-2021 at 02:36 AM.
07-16-2021, 06:45 AM - 2 Likes   #5
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As a wildlife photographer I would definitely keep the faster lenses. Many animals are nocturnal, and no matter how high ISOs you have, eventually you run out of light. The more leeway you have, the better.
07-16-2021, 07:21 AM - 2 Likes   #6
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QuoteOriginally posted by kypfer Quote
The a/f performance of the K-3iii is enhanced at f/2.8
This has been the case since at least the K-3 with the same limitations, center column only. (At least it was a marketing point when I bought mine.)

07-16-2021, 12:07 PM   #7
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I missed the 150-450, kept that. I'm excited to use Astrotracer both on the 11-18 and longer, just bought an IDAS LPSD-1 filter in 82mm, will fit the 11-18, the 500mm Tamron, and the 150-450 with a slight ring. We also kept the 70-200 DA*, it rocks.

I used to drag (into backpack wildlife shoots) the 300 FA* 2.8, a Greenie Manfrotto w/ gimbal, and.... Well you know. The 300 took too much of my diminishing "lift capacity". I hated to lose the FA*300/2.8 but I am hoping that the DA* F4 will "keep us afloat" EV wise....

With more and more excursions in cramped quarters and day trips, smaller is getting better.


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