[skierd]

I shoot mostly landscapes and wildlife, some portrait work. Currently have a k-30, 20-40, 50-135, and a K300 f4 and they meet almost all of my needs, will replace the k30 with either the k70 or the k3's replacement and eventually add an ultrawide.

I'm thinking about moving away from aps-c.

With the k-1, I'd have a similar setup of a FA31ltd, a FA24 f2 or FA20 maybe, and a 70-200 with the 1.4x.

With the 645d, I'd get a 35mm, 55, 75 LS, FA150-300, and a 400 5.6. All used of course.

What would you choose?

[bertwert]

I'd probably choose the K-1.

[Adam]

I'd go with the K-1. More versatility and more lens choices, plus better image quality in many scenarios (via shake reduction, pixel shift, etc.)

[pathdoc]

It has always been my understanding as someone who drools at the Medium Format door but likely will not enter that particular Promised Land, that the K-1 with all its enhancements running flat out and mounted on the same tripod to take the same shot with the same conditions nibbles at the heels of, but does not quite catch, the 645Z in pure performance terms (and this is before size, cost and ergonomics are figured in). On that basis, the 645D should be the no-contest, hands-down loser in a battle with the K-1.

Or should it?

[osv]

the k-1 will have better pq than the 645d in just about every scenario there is.

this is dr for the d810 vs. the 645d, for example:

[phat_bog]

K-1 configuration for sure.

i've got both. and since i bought the K-1 two moths ago, think i only touched the 645D twice while housekeeping as my place tends to get dusty easily

[Smolk]

the k-1 will have better pq than the 645d in just about every scenario there is.

this is dr for the d810 vs. the 645d, for example:

There were still quite a few users having both that preferred the 645D, so this is not the full picture. Generalised answers never work

[C_Jones]

I don't have a K-1, but it would seem the viable choice per the amount of lenses available for it (as been said) and the more conservative pricing.

Of course the 645 series is another type camera, in another category, and I would not see comparing it to the K-1 as useful being that they are different formats. Obviously both perform well, not leaving much else to ask for in their categories.

It really depends on what format the user is interested in.

[pinholecam]

I would get the K1.

Features like astro tracer are a plus.

Then there is better AF and lens choices, though if you want the best in IQ, it does mean getting some new lenses on the wide end.

[skierd]

The amount of lenses available to either system doesn't really bother me. I know what I use and I don't keep what I don't shoot.

With a k-1, the 31 would be my walkaround, landscape, and intimate portrait lens much like the 20-40 is for me currently. Maybe adding the DA*55 for portrait work. If Pentax releases a similar lens to the Ltd zoom in full frame, I'll probably go with that. The 70-200 replaces the 50-135 that I shot with 80-90% of the time. Adding the 1.4x TC and keeping or replacing my 300mm takes care of my wildlife needs. An UWA is on the short list for the northern lights

With the 645d, the 35 becomes my wide lens, the 55 and 75 my portrait lenses, 120 macro is for portraits and close up work, and the 150-300 replaces the 50-135 as my workhorse. The 400 would be my wildlife lens. I'd also complement the body with a 645N to shoot film (35mm film doesn't interest me anymore as I no longer have a local film lab and have decided that if im going to send film out id prefer to work in MF) and eventually replace the D with a Z.

Part of the rub is while the k1 is a great deal at $1700, the 645d is down to $2500-2800 and the 645 FA lenses, 2nd hand, are better priced than the new DFA FF glass.

[biz-engineer]

645D is rather heavy for carrying for landscape and dynamic range isn't as good as with the CMOS sensors currently in K1.

I'd suggest K1 and three lenses.

1) K1 + 24-105 (DFA24-70 or DFA28-105 or Sigma 24-70 or Tamron 28-75) + DFA150-450 + DFA100 macro
Standard zoom covers everything including landscape. Prime covers portraits and macros.

2) K1 + 24(8)-70(105) + DFA70-200 (Tamron or Sigma 70-200) + TC + DA560
70-200 covers portraits, 70-200 with TC covers some short range wildlife, DA560 covers wildlife+birds.

(2) is better but more expensive.

With a k-1, the 31 would be my walkaround, landscape, and intimate portrait lens much like the 20-40 is for me currently. Maybe adding the DA*55 for portrait work. If Pentax releases a similar lens to the Ltd zoom in full frame, I'll probably go with that. The 70-200 replaces the 50-135 that I shot with 80-90% of the time. Adding the 1.4x TC and keeping or replacing my 300mm takes care of my wildlife needs. An UWA is on the short list for the northern lights

Ok, I see. Looks like you're mostly using 50-135 and landscape including wide angle, occasional wildlife but not so much.

Part of the rub is while the k1 is a great deal at $1700, the 645d is down to $2500-2800 and the 645 FA lenses, 2nd hand, are better priced than the new DFA FF glass.

Second hand and new are different. Can't compare the price of a new car to price of used car, otherwise, no one would buy new cars. You could also consider second hand K mount full frame glass and it'd be a lot cheaper than second hand 645 lenses.

Beside actual image quality you get, the advantage of 645 is you can feel and appreciate shooting in first class ;-) (like seating in senator airport lounge and flying business class, it feels good). In that case, I'd go for a 645D.

[Nicolas06]

I shoot mostly landscapes and wildlife, some portrait work. Currently have a k-30, 20-40, 50-135, and a K300 f4 and they meet almost all of my needs, will replace the k30 with either the k70 or the k3's replacement and eventually add an ultrawide.

As a side remark, K70 and K30 are basically the same bodies. One has the new electronic apperture but you don't have lens that need it anyway. There the articulated back screen otherwise or a more modern sensor.

A K3 on the other hand is similar price but a very different piece of gear, old flagship. It has much better AF in particular, better build quality and is given for 200 000 actuations.

Except if you are really after the video features or the articulated screen is a must, K3 is better on all accounts.

[biz-engineer]

With the 645d, the 35 becomes my wide lens, the 55 and 75 my portrait lenses, 120 macro is for portraits and close up work, and the 150-300 replaces the 50-135 as my workhorse. The 400 would be my wildlife lens.

645D sensor size is approx. 44mm wide and K1 sensor is 36mm wide, that's 1.22x.
35mm on 645D is not so wide, for the wider dimension of the frame, it is like a 28mm lens on a K1, 19mm on your current cameras.
150-300 on 645D is equ. to about 118-237 on a K1, 79-158 on your current cameras, not really the range of a 50-135.
400mm -> 210mm with your current setup, not up to your current 300mm.

[Nicolas06]

645D sensor size is approx. 44mm wide and K1 sensor is 36mm wide, that's 1.22x.
35mm on 645D is not so wide, for the wider dimension of the frame, it is like a 28mm lens on a K1, 19mm on your current cameras.
150-300 on 645D is equ. to about 118-237 on a K1, 79-158 on your current cameras, not really the range of a 50-135.
400mm -> 210mm with your current setup, not up to your current 300mm.

This will mostly depend of what aspect ratio you'd tend to use. If you favor 4/3, and reframe your K1 picture to be 4/3, the actual effective ratio difference is 1.375. If on the contrary you reframe your picture of 645 to be all 3:2 the actual ratio is indeed 1.22.

If you don't care and shoot the full frame of each sensor without cropping, the ratio is in the middle actually at 1.29.

[biz-engineer]

If on the contrary you reframe your picture of 645 to be all 3:2 the actual ratio is indeed 1.22.

Yes, it's hard to get a focal length ratio when the form factor isn't the same. x.122 I considered for landscape photo in "landscape" :-) orientation. It depends if you consider doing a portrait of a landscape or a landscape of a portrait.