[epstar]

Thanks so much for the feedback folks. I have Fuji bodies and used my Pentax-M lenses on there with great results. The trouble is the cropped sensor, I can’t get the same field of view between my Pentax film bodies and my Fuji.

I’ll have to look into the metering issues. The Fuji worked perfectly with aperture priority and focussing was extremely easy with focus peaking. I’m not familiar with green button metering or how the metering is done on a Sony body. With Pentax M lenses is manual the only option or will aperture priority work on the K1?

[pinholecam]

I'd say the A7iii for the better focus accuracy with magnification and faster focusing with focus peaking.
Metering is not a big issue as it meters with the lens stopped down in Av and Tv mode.
There is also the advantage of having a live histogram to gauge exposure (which is only present for Pentax cameras for lenses with the A pin).
The downsides are :
Sensor stack which can mean fuzzy edges for some old lenses (esp wides)
Interface
Sony's commitment to their products (they do switch/end the product line if it does not make enough); But you will just be buying a body, so its fine
Light leaks for cheap adapters (get at least a good Kipon one)

The things going for a K1 will be :
1. More resolution; pixel shift; astro tracer, composition adjustment
2. Better interface
3. Sensor stack seems to take care of the older lenses better on the edges (my own experiences)
The downsides being :
1. Focus indicator is probably only accurate for f2.8 lenses onwards
2. Will need a focus screen change (if possible) and/or magnifying eyepiece for more accurate MF
3. Green Button metering can be a pro/con, depending on how one accepts/uses it (I'm neutral to it)

Personally, I have shifted the use of all my MF lenses to my A7 and my K1 uses all my AF lenses.
The only MF lenses I use on the K1 nowadays are for landscape shooting.

[Cee Cee]

just one comment I'd make is that I find using my old takumar lenses (switched to man on lens) is that the Sony (A6000) automatically adjusts the screen & EVF brightness when you stop down the lens so the brightness is pretty much the same on F1.4 as it is on f11 which is kinda like what happens with my spotmatic with the auto diaphragm. If I do that with my K30 I don't see a lot in the veiw finder at F11. As you rotate the aperature ring you see a momentry darkening of the screen but it quickly comes back to normal brightness and the focus peaking clearly showing the depth of field change.

I can't say that this would be applicable to to your situation but worth checking out, I find it a big advantage.

[SSGGeezer]

The biggest problem with the Sony? It is made by Sony and future support is by Sony. And it is priced along the lines of how the Walkman was priced in relation to every other available cassette player back in the day. Premium now, obsolete later.

[Rondec]

If you like EVFs the Sony is better. If you prefer an optical viewfinder then Pentax is better. Specs on the Sony in many respects will be better as well, but the K-1 images are amazing to work with and to my eye have better still photo results than the A7 III.

[pentaxfall]

According to my friend Sony build quality is poor. Two of his G-master 70-400mm lenses stopped working after he dropped the bag from 2-3 inches above the ground. Basically he stumbled and bag fell from the 2-3 inches height. This was not even ground, it was trunk of his car. Once he was on helicopter tour and camera froze. He carries Canon camera also and that saved the day.

On one occasion Sony did not repair instead replaced it with latest g-master version saying it is too expensive to repair. He did not pay for replacement.

[pakinjapan]

if you need a build-in Astro tracker, K-1 is the only answer. and it seems like the K-1 has a way way better built and weather resistance.

beside that, I think Sony's size and weight are the only real main advance to me. (may be autofocus too)

Both has their own strange, and I have absolute zero brand royalty, so I said, pick the one you feel like you will take it out with you more often. I think you can not go wrong with either one of them anyway.

[antipattern]

I once tried the A7III at a local shop. It handled nicely and my partner is planning on getting it for her video work. My heart is with Pentax though, and even though the K1 has a bit much heft to it, i decided to get it over the A7III. The main reasons are price, features (Astro tracer, GPS) and the limited lenses. Gosh, I just wish they made a super wide DFA 21 Limited that did starbursts like the DA15...

[BigMackCam]

If you like EVFs the Sony is better. If you prefer an optical viewfinder then Pentax is better. Specs on the Sony in many respects will be better as well, but the K-1 images are amazing to work with and to my eye have better still photo results than the A7 III.

I think that's a very simple and rather accurate summary. I'd perhaps add that the 36MP resolution the K-1 / K-1II vs 24MP on the Sony isn't to be overlooked, but that depends on your needs and priorities. None of the cameras I shoot with have more than a 24MP sensor, and some have considerably less... It's all good to me. But a 36MP full-frame sensor is capable of resolving a startling amount of detail with the right lens, and offers more flexibility in cropping whilst retaining acceptable IQ

[MJKoski]

Green button metering is a hassle with Pentax body when using fully mechanic lens without aperture coupling. It is not accurate when light starts to drop and liveview histogram does not work when using manual exposure mode.

Sony's metering works with all kind of lenses, be it native FE or dumb lens without any contacts.

However, adapter is an adapter. One may get a decentered one or one with incorrect register distance and lose infinity focus. I would say that whatever brand one uses, one should get brand lenses for the sake of mental health.

[pentax360]

It depends on if you want an optical viewfinder or not?

[surfar]

I have Fuji bodies and used my Pentax-M lenses on there with great results. The trouble is the cropped sensor, I can’t get the same field of view between my Pentax film bodies and my Fuji.

Well,If you use a Focal reducer on the Fuji you will get a 1.1x crop...almost the same FOV as your film Pentaxs.Oh,you might also gain some light too.

[Kerrowdown]

brought into the house by the lovely Tess..

Isn't that spelt incorrectly... should it not be "luverly Tess"...

[Jonathan Mac]

I've given this same question a lot of thought, although in my case it's purely hypothetical as I can't afford to go FF.

I also use a Fujifilm camera with my K-mount lenses and they work in aperture priority there, which they don't on my K-mount digital cameras. Stop-down metering is unreliable at best and I find just going manual and making small adjustments works better. All-in-all, exposure is better on a mirrorless camera than it is on a native (but crippled) digital Pentax, and I assume the A7 series will work in Av mode in the same way as the Fujifilms.

The Sony has an EVF rather than an OVF - I've never used an EVF so I can't say what the experience is like, but as it can focus peak (which an OVF can't) then it may be better, though the K1 is FF so this will allow more accurate manual focusing than I can get on my K3.

At the end of the day there are two main deciding factors for me - build quality and lens prices. I've read numerous comments about the build quality (including light leaks) on the A7III and they would worry me a lot, whereas the K-1 is reputed to be very solid, and as an owner of a K3 I am confident that the K1 would be markedly better than the A7III in this respect.

The big problem is lens prices. Pentax have reasonably priced FF lenses (not including the new ones, of course, which are very expensive) and an extensive used market plus third-party options. Sony FF lenses are extremely expensive for what they offer - £679 for a 35mm f/2.8??? £699 for a 55mm f/1.8??? Are they joking??? Sony's FF system suffers the same problems as their APS-C (NEX) system - good lenses are few and far between and extremely expensive. This is the reason why I chose Fujifilm's X system over Sony's NEX and it still holds up today. If I bought an A7III it would be to use purely with adapted lenses, while on a K1 I could use AF lenses, albeit the older ones, not the new mega-expensive, heavy, gigantic ones.

There's no denying the advantages of the A7III but I would go for a K-1, but of course this would depend on what you plan to use it for and your existing lens collection.

[MJKoski]

I assume the A7 series will work in Av mode

Manual mode works perfectly as well if "Setting effect" is set to "ON". It emulates the exposure set manually. Pentax could do FW fix to allow this as well. It cannot be that complicated.