[Rondec]

The differences have been covered at least somewhat already in this thread. I would just add that to me, if you shooting in low light settings, or do a lot of portraiture or landscape photography, then full frame is probably beneficial for those applications. If you do mostly macro photography, birding, or wildlife, then having a crop sensor is probably adequate.

In a sense, a full frame sensor like the K-1, has a 15 megapixel crop sensor inside it. If you shoot in crop mode, you do get faster frame rates, so that is something, but it does seem silly to buy a full frame camera in order to shoot it in crop mode.

I guess the last thing I would add is that the biggest thing that the K-1 brings from what I can see is better dynamic range throughout the iso range. This is something that is really handy if you do much post processing, but something you might not notice if you just shoot straight out of camera jpegs.

[biz-engineer]

If I print any larger I'll need a bigger house. That's going to add a lot to the cost.

I agree. Photography can be very costly if you don't set limits.

[Wheatfield]

A few days before Xmas B&H sent a helpful email explaining to the technically challenged like myself why full-frame sensors were better. Pixels as buckets gathering light and bigger buckets were better. I can take it on faith and fortunately have the discipline not to impulsively order my K-1. So, is there a question? Accepting that the product of a full-frame will be better than my K-70, my question is how much better? Can this be expressed in a percentage? (ignoring a sea of technicalities) Is the superior reproduction more noticeable in large prints? Is there a great advantage in highly creative post-processing? Those who make a living with photography, are editors and other professionally buyers exceptionally demanding of quality that only full-frame, or better, can meet?

I can't speak to percentages, but the end result from my K1 is significantly better than from my K3 or any of the APS-C cameras I've used. The difference is similar to what I saw when I moved from medium format to large format. Most of the difference is the look of the images. The full frame has more depth.

[northcoastgreg]

For me, the biggest issue with FF is the price, size, and weight of quality FF zooms and telephoto glass. I'm not a big fan of large, heavy lenses. Before I was willing to add an FF camera to my arsenal, I had to find compact, light-weight zoom lenses whose quality I could live with; and that's what I found with the DFA 28-105, the FA 20-35, and the F 17-28. The combined weight of those three lenses is less than the DFA 15-30. Not only that, they actually weigh less than the lenses they replace in my APS-C kit (DA 16-85, DA 12-24, and DA 10-17), which is rather astonishing to reflect upon.

Is the image quality better with these three FF zooms on the K-1? Yes, it's better. I wouldn't say it's better by leaps and bounds, and I couldn't put a number on it, but it does allow me to capture more detail. But what I've enjoyed most about the K-1 is, well, it's just an easier camera to use. Small cameras have their place, but the fact is, despite all the mirrorless propaganda, smaller cameras don't handle as well as larger cameras. While I enjoy shooting with my KP and appreciate its compact size, because it's a smaller camera and the buttons and wheels are all kind of jammed together, I'll sometimes hit the wrong button or scroll the wrong wheel. For example, I'm constantly hitting the playback button when I mean hit the green button, which is kind of annoying. And I don't dare leave the e-dial on my KP on ISO because I've mistakenly turned the dial and wound up shooting at a higher ISO than I wanted to. I don't have those issues with the K-1. Because of the size of the camera, the button and dials have appropriate space between them, which makes the camera easier to manipulate when I have my eye to the viewfinder. A larger back LCD is also a huge plus. The K-1 simply provides a better all-around shooting experience for me than any other camera I've used.

[ZombieArmy]

Personally I haven't been able to confirm that in blind tests. The tests I've run, shooting in most cases with a k-1 and a K-5 have produced very similar images. But those were in good light and with good composition. 16 MP is actually quite manageable. Someday I'll get a couple where the K-1 is significantly better, but, it hasn't happened yet. So far we've run maybe 4 tests, so the sample isn't large.

I still think the K-5 sensor is one of the best Pentax has ever put in a camera. I compare my K-01 to my KP in terms of IQ and it really isn't a substantial jump forward. If it wasn't for the huge leap in features I'd have been a bit disappointed.

[Ash]

The K-1 simply provides a better all-around shooting experience for me than any other camera I've used

Above and beyond the small perceivable benefit in IQ and printable size, this has got to be one of the main drivers for photogs to go from APS-C to FF.

I had to find compact, light-weight zoom lenses whose quality I could live with; and that's what I found with the DFA 28-105, the FA 20-35, and the F 17-28

Choice of lenses to carry around is a big consideration before dropping large amounts of money on the new DFAs. Is having the DFA 15-30 going to give you weight to IQ value in the long run? Only each photog can answer that question for themselves. I'd love to have the Pentax FF lenses for their IQ; though they are heavy, large and expensive. I will be making do with Sigmas and Tamrons for now.

I still think the K-5 sensor is one of the best Pentax has ever put in a camera

It has certainly been the longest running sensor in the camera lineup. I think over 16 cameras developed by Pentax/Hoya/Ricoh featured this 16Mp sensor. And for good reason - it seemed to strike a great balance between resolution and high ISO performance. Until the K-3 came along. For those who have compared them, does the K-1 sensor in APS-C crop mode perform much the same as the K-5?

[GUB]

does the K-1 sensor in APS-C crop mode perform much the same as the K-5?

I went from the K01 to the K1 and I think the answer is yes. Enough so that I am looking to go back to the K01 for closeup work (or thinking in crop mode on the K1)

[clackers]

The K-1 is really a double sized serving from the wafer the K-5 is cut from. You can see that in the DxOMark screen measurements of noise and dynamic range.

The Mk II adds the noise reduction chip from ISO640 onwards.

[cpk]

Music to the ears of us who can’t indulge their GAS

Yes, yes, yes!

Besides timb64's comment, what, to me, is missing from this thread is street photography. I certainly don't question the advantages of the K-1's larger sensor which has to be an advantage when cropping an image, a common occurrence when doing street photography. But the K-1 is considerably large than the K-5/K-5 II I use (see https://camerasize.com). I used to use Leica Ms (long gone now); and the K-5 profile is similar, given that it is a dslr rather than a rangefinder (it feels similar in my hands). Any larger camera, such as the K-1, is going to be more conspicuous.

[normhead]

Yes, yes, yes!

Besides timb64's comment, what, to me, is missing from this thread is street photography. I certainly don't question the advantages of the K-1's larger sensor which has to be an advantage when cropping an image, a common occurrence when doing street photography. But the K-1 is considerably large than the K-5/K-5 II I use (see Camera Size Comparison). I used to use Leica Ms (long gone now); and the K-5 profile is similar, given that it is a dslr rather than a rangefinder (it feels similar in my hands). Any larger camera, such as the K-1, is going to be more conspicuous.

The K-1 was announced as a "Field Camera" . It's not designed to be a camera fpor street photgraphy. NO camera can be everything.

[Wheatfield]

The K1 gives better looking images but is a little slow in some ways.
This is not to say the K3 doesn't give good picture, it most certainly does, and does it faster. The K1 gives better picture..

[Ash]

The K1 gives better looking images but is a little slow in some ways.
This is not to say the K3 doesn't give good picture, it most certainly does, and does it faster. The K1 gives better picture..

You mean slow FPS shooting or AF or shutter lag? 4.4fps is no slouch, but it’s certainly not a thrill-sports camera.

[reh321]

I still think the K-5 sensor is one of the best Pentax has ever put in a camera. I compare my K-01 to my KP in terms of IQ and it really isn't a substantial jump forward. If it wasn't for the huge leap in features I'd have been a bit disappointed.

At ISO 100, I would expect a KP to capture more detail than the K-01, which would matter only if there is a lot more detail in the scene {or if you need to seriously crop}

At ISO 10000, I would expect the difference to be so dramatic you wouldn't have to explain it to anyone.

[ZombieArmy]

At ISO 100, I would expect a KP to capture more detail than the K-01, which would matter only if there is a lot more detail in the scene {or if you need to seriously crop}

At ISO 10000, I would expect the difference to be so dramatic you wouldn't have to explain it to anyone.

I feel like I should do a side by side comparison for science.

[Wheatfield]

You mean slow FPS shooting or AF or shutter lag? 4.4fps is no slouch, but it’s certainly not a thrill-sports camera.

Slightly slower framerate and I think write times are a bit longer.
The slowness extends to my desktop where some processing tasks are noticibly slower.