[Kozlok]

For me, the APS-C has a huge IQ difference due to the fact that the K1 is too heavy and I would tend to leave it home, whereas with the APS-C camera, I usually take it along whether I plan to use it or not.

I agree with the others that there is not a huge IQ difference to the K3III, but that autofocus performance blows me away. I get a much lower rate of poorly focused shots (grand kids mostly), and high-ISO is better. For a well-focused, low-ISO landscape at f5.6? Zero difference.

[brainwave]

I tend to agree that in my case KP + da*16-50 would be more reasonable option but... guys, have you never heard the voice of that little devil whispering softly to your ear "buy K-1"? You know what I mean :-D I had some opportunities to play with K-1 and was amazed by it... soooo, tough decision indeed, have to toss a coin ;-))

Think carefully Paulo. Moving to FF is no joke. With the K-1 at once all your current lenses for KP would become sub-optimal. Then you need to sell them and shell out $1200-$4000 for zooms EVERY TIME you want to buy one new. You likely already have many of these focual lengths for KP, or can get them much cheaper. The things you already have, such as much reach for much lesser money for bird photography, size and weight advantage, aperture bracketing, are gone with the K-1. So that's a shock. The things you get are shallower depth of field and lower high iso noise, which is frankly NOT at all a practical improvement in any image. Neither are noticeable.


Unless you have to print huge size, just ignore that voice. Buy a lens. Buy another APS-C if you must. But staying away from full frame would be my honest opinion.

[BigMackCam]

For me, the APS-C has a huge IQ difference due to the fact that the K1 is too heavy and I would tend to leave it home, whereas with the APS-C camera, I usually take it along whether I plan to use it or not.

Same here. I have a wonderful full-frame Hasselblad HV (Sony A99) and lenses that mostly get left at home in favour of one of my APS-C cameras. APS-C format has become the "sweet spot" for me in terms of image quality plus convenience and comfort. I totally get why folks buy the K-1 / K-1II, and I love shooting with a full-frame camera, but for my use-cases APS-C offers greater convenience and comfort with only small sacrifices in image quality that are essentially immaterial to me...

[Paulo]

You are partially right. Partially because I already have da*300 and da*60-250 which work perfect on FF, so I would need to invest only in FF body and 24-70. But I'm afraid that after a while I would start thinking about 31/43/77 (yes, I'm crazy!!!). This is the real reason which holds me back from K-1II. Weight? C'mon, in my backpack sometimes I carry Pentax dlsr and my Hassy 500c...

If the new da*16-50 was somehow cheaper I would not have any problem and just buy it (Ricoh, can you hear me?!?!!??)

Anyway... guys, thank you very much for this discussion. I'm going to dip my head in cold water, cool it down and focus on apsc

[MossyRocks]

For me the K-3iii would be the hands down winner. I say this looking at the type of photography I like doing the most which is astro. So there I likely wouldn't be using a zoom but the isn't a light loss issue between the 2 lenses since they are both f/2.8 ones, granted there would be other considerations for the lens but if the 16-50 is generally thought of as being better during the day it will likely also get better faster in the dark. So that just leaves how the bodies perform in low light and there the K-3iii would be a better choice having a BSI sensor and lower high ISO noise. If I look at other lenses I own and do astro with the K-3iii becomes an even clearer winner since to get the same framing with a K-1ii I would have to go up to a longer and slower lens. So if I used a K-1ii instead of my K-3 I would have a bit less than one stop less noise at the ISOs I shoot at for deep sky objects, but instead of using my A* 400/2.8 I would have to jump up to an A* 600/4 which eats the noise benefit of the lower noise of the K-1ii and then some. Also the 600/4 isn't as well corrected so unlike my A* 400/2.8 where I run it at f/3.5 I may have to run a 600/4 at f/5.6 eating a further half stop of light but that is just a guess as I don't have an A* 600/4. So there running a K-1ii would clearly be a worse setup than what I currently run. Then switch out my K-3 for the K-3iii and I would experience a dramatic improvement in image quality for astro shooting, even over a K-1ii if I had one of those.

[ChristianRock]

I think the question might be, will you stick to just that one lens, or is there something else in the Pentax lineup that you are considering?

Will you be adding any full frame lenses? Or do the DA Limiteds perhaps appeal more to you? If you go wider, does the DA*11-18mm f/2.8 have an appeal because you might be able to use filters more easily? Or is the DFA 15-30mm f/2.8 a better option on the K-1, with the extra resolution?

You said you do nature, does that include telephoto work? That usually ends up tilting the odds in the APS-C favor because of the extra reach.

[biz-engineer]

I wonder what set would give overall better quality - K-1 with dfa24-70 or new K-3III with new da*16-50. K-1 is a real monster in terms of IQ but the lens itself is just good only whereas the new da*16-50 seems to be one of the best apsc zooms whenever made. Better body with worse lens or better lens with little bit worse body?

I asked such question a while ago. IQ wise, the K1 will be better but given the more recent sensor technology used in the K3 III the gap between K1 and apsc isn't as large as it used to be. K1 isn't state of the art anymore, for 24x36mm sensor better can be found in the market. On the other hand, the K3 III offers significantly more speed and no much less resolution. So, it comes down to how large prints we make to tell if all the resolution is needed, and if not then I'd say if not only about the resolution the K3 III has a better figure of merit. BTW, 36Mp vs 24 or 26Mp isn't as big of a difference as it seems , 36Mp is 7360 pixel wide, 24Mp is 6000 pixel wide, added to that is the DA*16-50 lens tech may be a tad better than Tamron 24-70 G1 re-badged lens. Ricoh should bring quickly a K1 successor model with 60+Mp, otherwise the K1 isn't giving justice to its Pentax D-FA* full frame glass quality, TBH.

[Bob 256]

I have to agree with texandrews. The two features the K-1 does offer, is more light per pixel (bigger pixel sites) which translates to slightly better sensitivity, and the ability to utilize FF lenses and enlarge their scope to near full capability of the lens (full capability of many lenses). You might also want to check features of each camera in detail. I've seen a couple of examples of negative reports on the K3 because of former Pentax features which were dropped. These were specialized features and probably don't apply to you but something to check out with a side-by-side comparison of features. As many have said, it depends on what you will use your new camera for and what kind of shots you want to take. Both are great cameras.

[biz-engineer]

IQ of cameras has far surpassed the requirement.

Such relative generalization may or may not apply, it all depends on end usage of images. Large format used to have its place with 500Mpixels equivalent, now putting apsc and full frame digital cameras into perspectives, digital is unimpressive resolution wise, and still into perspective with large format film the difference between apsc and full frame is very small. For instance, I printed 20x30" photographs from K3 files (not even K3III) and I print 24x36" from K1 files, the difference isn't that much, to a point where I wonder why I haven't kept my K3 and bought a 645z instead of getting a K1. So basically today, either digital is good enough or it's not , and if digital isn't enough there is sheet film formats , 4x5, 8x10. I'd put format along a scale: tiny digital (mobile phones, emphasis on portability), apsc and full frame digital ILC (emphasis on speed), and large format film (emphasis on resolution, but a very slow process).

[UncleVanya]

I tend to agree that in my case KP + da*16-50 would be more reasonable option but... guys, have you never heard the voice of that little devil whispering softly to your ear "buy K-1"? You know what I mean :-D I had some opportunities to play with K-1 and was amazed by it... soooo, tough decision indeed, have to toss a coin ;-))

Buy both. Lol. (Says the guy with far too many systems and no k1. )

[brainwave]

I asked such question a while ago. IQ wise, the K1 will be better but given the more recent sensor technology used in the K3 III the gap between K1 and apsc isn't as large as it used to be. K1 isn't state of the art anymore, for 24x36mm sensor better can be found in the market. On the other hand, the K3 III offers significantly more speed and no much less resolution. So, it comes down to how large prints we make to tell if all the resolution is needed, and if not then I'd say if not only about the resolution the K3 III has a better figure of merit. BTW, 36Mp vs 24 or 26Mp isn't as big of a difference as it seems , 36Mp is 7360 pixel wide, 24Mp is 6000 pixel wide, added to that is the DA*16-50 lens tech may be a tad better than Tamron 24-70 G1 re-badged lens. Ricoh should bring quickly a K1 successor model with 60+Mp, otherwise the K1 isn't giving justice to its Pentax D-FA* full frame glass quality, TBH.

Of course, if large print comes in then K1 has a slight advantage, but honestly I think if that's the requirement you are a professional and could just spend on a medium format. I honestly think full format doesn't have much of a place. Question to you - have you seen any side by side comparison of how K1 is better in low light?

[Jonathan Mac]

I would be surprised if the K-1 didn't give better results all else being equal, despite being an older camera with an older sensor. Still, it would depend on many factors.

If I had the money to buy one or the other I have to say I'd go with the K-3 III but that's largely due to having considerable investment in APS-C lenses, some of which are really great and have no FF equivalent.

[jlstrawman]

have you never heard the voice of that little devil whispering softly to your ear "buy K-1"? You know what I mean

Yes, it's called FOMO.

[UncleVanya]

You are partially right. Partially because I already have da*300 and da*60-250 which work perfect on FF, so I would need to invest only in FF body and 24-70. But I'm afraid that after a while I would start thinking about 31/43/77 (yes, I'm crazy!!!). This is the real reason which holds me back from K-1II. Weight? C'mon, in my backpack sometimes I carry Pentax dlsr and my Hassy 500c...

I own the fa* 300, da* 60-250, da* 200, dfa 100, fa 77, da 70, da* 55, fa 50 f1.4, f 50 f1.7, fa 43, da 40, fa 31, and a few other lenses that are acceptable on full frame. On apsc I add: da 55-300 (old version), da* 50-135 (I love that lens), da 18-135 (a workhorse), da* 16-50, dal 18-50, da 20-40, da 12-24, da 21, da 10-17, da 15, da 14, and a Rokinison 8mm. (Plus others)

I shoot full frame on a Sony A7riii (long story involving trying to keep my 81 year old dad happy) where I have their 24-105, 85 f1.8, 28-70 f3.5-5.6, 28 f2 and an adapter making that lens a 20mm f2.8. My original plan was to get the la-ke1 monster adapter to reuse my full frame lenses in autofocus. That plan has been impacted by Covid and chip shortages.

Additionally I have multiple m43 bodies. And lenses.

Why do I mention all of this? I find that my KP and even the aging K-3 is rarely less capable at producing good images than the Sony. Where I struggle with the Pentax KP and K-3 is with focus accuracy on a few lenses where a slow manual focus process works better (and EVF is slightly easier to manage this on than live view. ) With a few images the extra dynamic range of the sensor seems useful but certainly not many.

I honestly am working on trying to motivate myself to cull the herd a bit. I am about to send a Tamron A Mount 70-300 to my dad with an adapter for his Sony A7rii. But I use many of these from time to time and can’t get excited about downsizing the collections. Buying into multiple formats is a slippery slope. Stay happy with apsc only and concentrate on technique and squeezing what you can from what you have.

[Paulo]

Stay happy with apsc only and concentrate on technique and squeezing what you can from what you have.

The most valuable piece of advice I recently heard... Thank you