[kfz]

Have been a Pentax user for a while (K20D & K5) I recently decided to move to FF. Borrowed my friends Canon5DII for 2 weeks.
My impression between K5 & 5Dii:
K5 feels more solid, better build
K5 has better white balance, especially under electric light. 5Dii way too yellow/red under electric light.
K5's sensor has better low light performance than 5Dii. This is a surprise to me. In the same brightness K5 needs lower ISO than 5DII assuming same speed and F.
5Dii's picture shows more contrast. Sharpness very close 5Dii maybe 1% sharper.
5Dii has more accurate auto focus, especially in lower light conditions.
5Dii has better/more accurate live view LCD focus. K5's live view focus so bad I avoid using it.
5Dii 's sensor shows brighter, richer color than K5
At the end it was the 5Dii's terrible auto white balance under electrical light backed me off. So I moved to a 2nd FF choice: Nikon D800E.
My impression after 1 week between K5 & D800E:
K5 still feel more solid and better build than D800E!
K5 still has better auto white balance under electric light than D800E, although the D800E is a little better WB compare to 5DII.
K5's low light performance ties the D800E in my view.(surprise to me!)
D800E 's IQ is noticeable sharper than K5. Maybe 3% sharper.If K5=95, 5Dii=96, D800E=98
D800E's Auto focus accuracy is better than k5. about the same as 5Dii.
D800E's sensor is richer, brighter in color. more than the 5Dii too.
D800E's build quality feel in between K5 & 5Dii.
I am happy with my D800E so far. But looking at the price difference between the 2.
I have to say the Pentax K5 is a very, very solid performer at a steal price currently.

[hcc]

Very interesting. Thank you for sharing.

[Doanh]

My wife's cousin (who is also my friend) has a D800 while I have the K-5. I can say that K-5 WB is really superior to the D800. High ISO of the K-5 is on par. However, focusing speed is way better on the D800. Anyway, I just want to say that I agree with the OP from my brief experience with the D800.

BTW, when I first got the K-5, I thought the color looks washed out and lower contrast compared to my previous K-7. Later I realized it's because of the wider DR. The K-5 is a really good camera!

Peter

[Bestzoom]

Thank you for sharing.
One other big difference is the compact size of K5.

I love Nikon (use Nikon for 20 years) but i now have Pentax due to its compact size.

[DeadJohn]

It's interesting to see how well the K5 holds up to newer more expensive cameras.

Some of the differences you note might be equalized using in-camera settings or while loading photos into post-processing software. The colors on the K5 can definitely be made richer and brighter. Maybe the D800 and 5D white balance under artificial light is easily fixed, too.

[Sinister]

Thanks for sharing. Having the old 5Di I can only comment on the general picture impression a 24x36 gives (so I am not talking about AF). And I have to look very closely and to think very long to justify moving into that area, especially taking into consideration that current FF models are still very expensive. Pentax is a sweet-spot-combo to me: great built-quality with WR, IBIS, great lenses in a small package

[derekkite]

Thank you for sharing.
One other big difference is the compact size of K5.

I love Nikon (use Nikon for 20 years) but i now have Pentax due to its compact size.

Indeed. The D800 is by all accounts an excellent camera, but compared to the K5 it is huge.

[vodanh1982]

5's sensor has better low light performance than 5Dii. This is a surprise to me. In the same brightness K5 needs lower ISO than 5DII assuming same speed an

I am not sure if K-5II has better low light performance than 5DII just because its ISO is lower. FF has lower noise than crop even with higher ISO. You need to compare two images side by side.

[jeanpascalc]

Recently tried a 5D2 with 24-105 and this is a heavy beast combination. In decent light the autofocus is miles ahead, no micro adjustment but I while it locks quicker I wasn't conviced if its more accurate. The very confusing thing though seems to be that then review zoom is a lot less powerful or the definition of the K5 is lower. This leaders to think the 5D2 is sharper when just comparing the camera LCD while the difference is barely visible when looking 100% on a computer. Note that I'm comparing with a DA 70 Ltd...

[LFLee]

For me, the FF advantage is the DOF. APSC will never have the same DOF feel FF have.

[jeanpascalc]

For me, the FF advantage is the DOF. APSC will never have the same DOF feel FF have.

DOF is definitely shallower on FF but sometimes you need more it (low light group shot for instance), I think APSC can help here and if you need even more DOF, go Pentax Q ;-)

[beholder3]

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