[RockvilleBob]

Three things I need to see.

Iso and noise. I suspect it will be worth it.
Better AF. We shall see. It isn't the focus point count that matters, in fact they are slightly denser than the K3. It is whether it can capture things quickly enough. The K3 just isn't quick enough to focus between shots in afc mode.
Does the frame rate drop substantially in afc mode? The crop mode is fast enough, and ff mode is workable as long as it doesn't get bog slow when focussing.

So I don't know yet. Right now I am noise and af constrained. The loss of resolution would be more than made up with two stops better noise characteristics.

I'm with you. If the K1 AF.C/tracking is up to or better than Nikon/Canon auto focus for action - I will upgrade. If not I will wait for the next high end K3 replacement and either buy that or be forced to switch to a different brand with stellar AF.C/Tracking.

[TaoMaas]

I will probably go FF at some point because all but 2 of my lenses are FF and take me from fish-eye to 400mm. Right now, shooting APS-C, I could use something a little wider in my lens selection so even if I stick with APS-C, I need to budget for a lens wider than 16mm. Plus, I've been holding out upgrading my DSLR until I could see how this all shook out, so a committment to APS-C would involve buying another body, too. So it's a pretty easy choice...FF body vs wide angle APS-C lens and body. I still plan to use my APS-C cameras. I figure that switching to my APS-C camera will be a bit like using a 1.4X teleconverter, but with a minimal loss to IQ. Plus, they still make damn fine images. Even once I go FF, I expect my daily camera to be one of my APS-C cameras.

[grahame]

I will get a K1 soon, but will also keep APSC cameras, and will upgrade to newer APSC cameras if they are good or my APSC camera develops issue.
FF and APS cameras compliment each other, and I might use APS system more in regular daily use. K5II + 20-40 + 70 is a great kit for family travel, and I can add 55-300 if longer reach is needed. Can't imagine taking K1+ 24-70 + 70-200 + tripod for a family vacation trip. My back and my wife will kill me :-).

[Winder]

No, it's easier to take pictures with a bigger depth of field.

You have 100% control of DoF with either format. Technically smaller sensors have a narrower DoF when controlling for all other variables.

[RMabo]

If I eventually get a K-1 then I will keep my K-x and/or my K-S2 with DA lenses. For the K-1 I do have the Sigma AF 24 f/2.8, Pentax FA 50 f/1.7 and FA 135 f/2.8. I would keep my APS-C camera/s and lenses for the small size and the joy I feel when shooting.

[Winder]

As much as I have bitched about Pentax not having a FF, I have to buy one.

[normhead]

As much as I have bitched about Pentax not having a FF, I have to buy one.

As much as I've told people they don't have to buy one, I have to buy one, just to show folks how open minded I am.

---------- Post added 02-29-16 at 10:09 AM ----------

You have 100% control of DoF with either format. Technically smaller sensors have a narrower DoF when controlling for all other variables.

Maybe you could explain that. I've shown any number of times that equivalence is equivalence, same everything for the same image, Maybe you know of some variable I don't know about. I used DoF and VoF as my constant and ISO and Aperture as my variables. The same image with the same DoF requires a smaller ƒ-stop in the larger format, letting in less light and a higher ISO. Noise, total light etc. all equal out.

I found, equivalence means equivalence. Functionally you have less DoF at the wider aperture settings in larger formats, but for any setting where both formats have the same FoV and DoF, they are functionally the same in every regard.

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Last edited by normhead; 02-29-2016 at 08:11 AM.

[Winder]

I used DoF and VoF as my constant and ISO and Aperture as my variables. The same image with the same DoF requires a smaller ƒ-stop in the larger format, letting in less light and a higher ISO. Noise, total light etc. all equal out.

Look at any DoF calculator. if all other variables are held constant and you only change sensor size, the smaller sensor has a narrower DoF.

Lets say you have a FF with an 85mm lens and an APS-C with 55mm lens. If you are holding FoV as a constant then you have to be changing the focal length of the lens (55mm vs 85mm) or you are changing subject distance. If you change from an 85mm to a 55mm you age going to a shorter focal length which gives you more DoF. If you keep the same 85mm lens and put it on an APS-C then you have to back up to keep the same FoV. Increasing subject distance increases the DoF. A 55mm lens can't render like an 85mm lens regardless of sensor size, but they are close enough that most people don't care. Changing the subject distance also changes the compression of the image regardless of sensor size, but again probably not enough that anyone will care. Then you have the compression effect of magnification that has to happen when you enlarge the APS-C image to match the FF.

Actual DoF though can be totally controlled with any size sensor. You just need the right glass.

[pete-tarmigan]

Before the official announcement, I told myself I didn't need a DSLR with a 24x36mm sensor. This is despite the fact that most of my lenses are for "full" frame. Once I saw the description of autofocus improvements and the price I changed my mind. I'll still keep one of my APS-C bodies.

[normhead]

Look at any DoF calculator. if all other variables are held constant and you only change sensor size, the smaller sensor has a narrower DoF.

Lets say you have a FF with an 85mm lens and an APS-C with 55mm lens. If you are holding FoV as a constant then you have to be changing the focal length of the lens (55mm vs 85mm) or you are changing subject distance. If you change from an 85mm to a 55mm you age going to a shorter focal length which gives you more DoF. If you keep the same 85mm lens and put it on an APS-C then you have to back up to keep the same FoV. Increasing subject distance increases the DoF. A 55mm lens can't render like an 85mm lens regardless of sensor size, but they are close enough that most people don't care. Changing the subject distance also changes the compression of the image regardless of sensor size, but again probably not enough that anyone will care. Then you have the compression effect of magnification that has to happen when you enlarge the APS-C image to match the FF.

Actual DoF though can be totally controlled with any size sensor. You just need the right glass.

I've done it, and you've got it backwards, a 55 from the same distance has more DoF than an 85. The 55 is on the small format, the 85 is on the large format. You need to stop the larger format down one stop to match the DoF if the two formats are APS_c and FF. I have actually gone to a DoF calculator and done this.

Same FoV, Same DoF, same ƒ-stop, more DoF for the smaller format.

[Winder]

a 55 from the same distance has more DoF than an 85

That is what I said. "

f you change from an 85mm to a 55mm you age going to a shorter focal length which gives you more DoF

[bobell69]

I plan on purchasing the K-1' but will wait for a few months. The new camera will complement my K3II

[TheOneAndOnlyJH]

That is what I said. "

Yes, but the misunderstanding is because you started out saying

Look at any DoF calculator. if all other variables are held constant and you only change sensor size, the smaller sensor has a narrower DoF...

The difference is how people interpret "all other variables held constant".

-If you understand it as maintaining focal length this is true, though it will change the field of view or perspective and depth compression of the picture. (Your first sentence)

-If you understand it to mean you maintain the same field of view and same perspective you must change focal length, and the smaller sensor actually has a wider depth of field at the same aperture / ISO / shutter speed. (Your second paragraph, and what Normhead is saying)

(To achieve the same DoF on FF by stopping down the aperture, you would have to adjust ISO or shutter speed to achieve the same exposure, which I don't believe fits the phrase "all other variables held constant")

[osv]

"all other variables held constant" is not equivalence, but that's how many people look at it, especially the m4/3 crowd.

how many times have we heard that smaller sensors give more "reach"? that so-called effective focal length doesn't come for free, there is a pq penalty.

[monochrome]

There *will* be plenty. Expect a DA lens bonanza in the marketplace in a month or two. I expect some of mine will be there

It has already begun.

MonochromeIsDoomed