[UncleVanya]

Keep in mind that lenses have a wider field of view on full frame. The FA 50 on a K-1 will have about the same field of view as the FA 35 does on the K-50, and the FA 35 will be wider on the K-1 (roughly the same as a 24mm lens on the K-50). To replicate the field of view of the FA 50/K-50 combination on the K-1 would require a roughly 75mm lens. So although your FA lenses will work fine, they will render differently, and you may want to acquire more lenses to get the same effect. I hear the FA 77 Limited is VERY nice, and would match that field of view. The DA 70 Limited is a bit cheaper, but is not quite full frame, especially at wider apertures (corner shading, and maybe some corner softness). There are also the D-FA standard zooms.

This is what I was going to say as well. APSC seems to work well for you. I wouldn't switch formats. I would wait a month and see if there are any announcements made that affect apsc for Pentax, maybe the looking awaited k3 ii replacement. Otherwise the KP is a great option.

[savoche]

I'll contribute with my two bits even though I think all points have been covered already. I have gone from K-5 to K-3 to K-1.

Would it be better for me to a) get a K3 or K3ii b) KP or c) just keep saving for the K1?

As I see it:
K-3/K-3II
+ fast frame rate (if you need it - good for hand-held bracketing e.g)
+ dual card slots (I like to have raw format on 1 and JPEGs for backup on 2)
+ topside LCD screen
+ good battery capacity
+ a bit better autofocus (and smaller AF points)
- not much high-ISO upgrade (if any) from K-5/K50
- somewhat bigger and heavier than the K50

KP:
+ very good high-ISO performance
+ flip-up screen
+ compact (very slightly bigger than the K50)
+ better AF
o just one card slot
o no top LCD
- not as good battery endurance as the K-3/K-1 (about the same as the K50)

K-1
+ very good high-ISO performance
+ big viewfinder
+ pull-out screen
+ dual cards
+ better AF
+ good battery capacity
o small topside LCD
o all (FF) lenses will give a wider field of view
- might require some new lenses to make sense
- heavier and bulkier

Will a K3 (or KP?) be enough of an upgrade from a K50 to be worth it?

For me it was. But if you are after better high-ISO performance I wouldn't look at the K-3. It's a better camera than the K50 in most other ways, but not that. The KP is notably better for high-ISO, about at the same level as the K-1 from what I've seen.

In your shoes I would probably go for a KP (or K-70). And if I were sensible that's what I would own as well. But I do love my heavy lump of a K-1

[mikesbike]

For your stated needs, superior low-light/higher ISO performance, and your interest in outdoors with documentary and portrait use, I have the KP and it is a virtually perfect design for street-shooting. Also great for nabbing candid portraits. Its control set is also a definite upgrade over what you have. Very fine build quality. It is versatile in its ability to change ergonomics, shape and size according to need, via the 3 grip sizes and also the optional battery grip. An upgrade for you in every way.

If you then later decide for a K-1, the KP was also designed to be an APS-C version of this FF model, with performance as close to it as possible, and can serve as its APS-C companion. For some applications, APS-C has its advantages, and for other uses, FF has its advantages.

There was another Canadian poster not long ago who found a great deal on a new KP through Amazon Canada.

[UncleVanya]

You can add a battery grip to the KP if needed but if the K-50 has been adequate in the battery department I wouldn't sweat it. I went from K-50 to K-3 and found low ISO improved mainly due to better autofocus and the 14 bit raws vs. 12 bit raws but real noise wasn't a lot better if at all - the improved noise processing I got from moving to DXO around the same time makes it hard to compare.

Do you shoot raw or jpg or both?
If Raw - try some noise processing programs if you haven't already. I really like DXO myself.

[zippythezip]

I can vouch the K70 feels like the K50. I know a guy in Canada who might sell his K70 cheap if your interested =)
K-70 for sale | Flickr
I did check your photos, very nice.

[The Squirrel Mafia]

Hello Pentaxians! So I've been using my trusty K50 for a few years but am feeling like I really need an upgrade for more megapixels and especially for better low light performance.

I've had my heart set on the K1 for awhile but it's not in the budget just yet (but I really want to go FF so will in a year or two).

I mainly do documentary photography with a lot of outdoorsy environmental portraits. Would it be better for me to a) get a K3 or K3ii b) KP or c) just keep saving for the K1? Will a K3 (or KP?) be enough of an upgrade from a K50 to be worth it? TIA for the advice -- I'm in a lot of photography groups but no one shoots Pentax

Examples of my work to give an idea of my requirements. I mainly use the FA 50mm 1.4 and 35mm 2.0 for lenses.
Ashley McMath (@ashleytheislander) ? Instagram photos and videos

You have a lot of nice pictures on your Instagram. If you got the majority of those with the K-50, I can only imagine what you could do with a K-1/1II. I'd actually suggest that camera in your case over the KP & the K-3II. I don't really see too many action photos that require some heavy duty AF algorithms. Those FA primes will shine on the K-1/1II.

[Wasp]

I looked over the K3/KP differences a few weeks ago. The K3 has GPS, dual card slots and big buffer in its favour. The KP has a later generation sensor that is better in low light. There is more to it (as pointed in detail in this thread) but to me those are the most important things. You make your choice and you pay your money.

If you find it hard to choose, there is an easy answer. Get a K1. It has a lot of good things. Great in low light, dual cards, GPS, the lot. Buffering comparisons gets complicated because of bigger files but such is life.

Going full frame gives you less depth of field and more bokeh, if you have the right glass. The big downside is the price of admission.

At the moment a lot of Pentaxians are playing the waiting game to dee what the Asahi centenary year will bring. I am in that camp myself. I had the opportunity to get a KP at a a good price last week. After some thought I let it pass and bought myself a Sigma 10-20mm f/3.5 instead.

My Kx and K200D are getting long in the tooth. I kind of need something more modern with a K mount. I have drunk some of the mirrorless Koolaid (in the form a Samsung NX1) and liked it far more than I thought I would. I am therefore hoping that my next Pentax will have an EVF. We'll see what the new year brings.

[totsmuyco]

If you can wait, next year Pentax may come up with surprises. Who knows, the k-3II replacement might come next year. If you can't, I'd say KP if you have the funds or the k-70 if you're on a budget. I wouldn't go for the older models. Future proof your gears. There may be some updates and it is to your advantage if you have the newer models.

[Theov39]

I have both the K-3 and K50 and prefer the K-3 for the better built quality, top LCD, better AF focus, and it's sheer rugged reliability but the K-50 really has beautiful images with a very special color tonal quality to the images that is hard to match. Was it the same sensor as the K-5? It is very close to the way Fuji film and the legendary Fujifilm S3 Pro camera used to look, so in terms of IMAGE quality I don't think the K-3 is necessarily an upgrade but in terms of the other factors I have mentioned it certainly it.

You also have to really think about what you prefer to do in terms of carrying around a camera. The K-50 (and K-70) are super light and small. The K-3 is still small but quite a bit heavier. The K-1 is a lot heavier again. If that is ok than fine but something to keep in mind. I don't have any experience with the KP so can't comment on that camera.