[pietro_d]

Hi all,
I have a Pentax k-x and a k20d. My question is : if I would go with both camera around, what is your suggestion, when to use the k-x and when the k20, for example in portraits, landscape, macros, night ... ?
I have more objective, so the idea would be for example one camera with a wide angle and the other with a tele.
Thank you very much in advance for your help
Pietro

This is my equipment:
Objectives:
Pentax DAL 18-55 1:3.5-5.6
Pentax A 50mm 1:1.7
Sigma APO DG 70-300 1:4-5.6
Tokina AT-X 60-120 1:2.8
Vivitar PK 28mm 1:2.8
Flash: Metz 52AF1

[ismaelg]

I have both. Before the K5II I used K-x for low light, K20 for everything else.
I'd use the slower lenses on the K-x to take advange of higher ISO capabilities.

Thanks!

[pietro_d]

Hi Ismaelg,
I find your suggestion very good and it was also what I was doing following my instinct , so the 50mm f/1.7 or 60-120 f/2,8 on the k20, 18-55 on the kx and when lowlight the kx.
The next question is what if using only the 18-55 and 70-300 ?
Is it correct k20+18-55 3.5-5.6 and kx+70-300 f/4-5.6?
Thanks again :-)

[ismaelg]

There is really no right or wrong. I would start with the 70-300 in the K-x because the longer the focal lenght the faster the shutter speed required to prevent motion blur. Also, the lens is bigger/heavier than the 18-55 and the K-x is lighter than K20.
But at the end, you should try all combinations and see which one produces the best results. There are many other variables like focus accuracy, back/front focusing, chromatic aberrations, resolution differences, sharpness, weight balance, ergonomics, file size handling, shooting style, battery life, format used (jpg or raw) etc. that may affect the outcome.
That is the best excuse to go out and have fun shooting the heck out of both

Thanks,

[pietro_d]

Thanks for the suggestions, it's a good starting point that I can consider.
And you're also right that the best choice is trying, going around shooting and having fun ;-)
Thanks :-)

[rbefly]

Hello Pietro, welcome to the Forum!
I don't own those two cameras, but have a similar choice with the K10D and K-5. The K10D, with the 10MP CCD sensor, is really best at ISO 100-400, not too good at higher ISO. The K-5 has great high-ISO performance, ISO 3200 is very useable and the noise is well controlled.
So, overall, I agree with Ismael, the K-x for higher ISO (and faster shutter speeds) and the K20D for low-ISO photo situations.
But, there's another factor; A tripod. Suppose you were taking photos of a sunset or sunrise, long exposures of 5 to 10 seconds? Or trying to catch lightning, or trails of lights on a roadway, long timed exposures. There, the low-ISO of the K20D wouldn't matter as much, fast lenses don't really effect the quality because you're not shooting wide-open anyway.
So, another way to view the choices; If it moves and you're trying to 'freeze' it, use the K-x. If it doesn't move or shutter speed isn't a factor (tripod), use the K-x.
For example, I usually take both camera bodies with me to the Botanical Gardens, along with a tripod. First, I walk around with the K-5 and (usually) shoot hand-held with the K-5 and macro lens. If I have to raise the ISO, no problem, within reason.
But, I may have seen a few special flowers that I'd like to capture with the lowest possible ISO and as much saturation, color rendition and depth-of field as possible. For these, I'd switch to the K10D, carefully set my tripod, stop the aperture down, use reflectors or flash, bracket each shot and generally take more time. A 'Still Life' photo with a longer shutter speed, in other words. As long as it's not windy!
If I take the tripod, the K10D is useful. Without the tripod, the K-5 is MORE useful. ISO, f/stop and shutter speed must match the scene, and the K10D has more limitations because the ISO 'ceiling' is lower.
Hope this helps!
Ron

[pietro_d]

Hi Ron, thanks, it surely helps.
On the k20d there's already a CMOS sensor instead of Ccd as in K10d but also K20d has lower performance in terms of higher ISO and fast shutter speed than k-x . And the reference to tripod I didn't consider at beginning but it's a main point to think about.
It can help also for my other question, and it confirms that k20+18-55,and k-x+70-300 is a good choice but in case of use of tripod , I could have better performance with the 70-300 on the k20. I have to have fun, as Ismael already sai ;-)
Thanks :-)

What about the Ccd sensor? I saw some photos from k10d and I like the effect of Ccd more than from CMOS dslr sometimes. Do you agree? Or can it be that it was more depending by the objective ?

[ismaelg]

In general, CCD images are regarded as "better looking" than CMOS in color rendition. But that's very objective. That's why I still use my K100D Super in studio work despite been only 6MP. In fact, in post proces I try to get the CMOS images to "look like" CCD.
But CMOS has far better performance in dynamic range, ISO, processing speed etc.

Thanks,

[Lowell Goudge]

The question about ISO capability/performance aside, have you been satisfied with the performance equally on both bodies, with all your lenses. I have a tamron 28-75/2.8 which , for what ever reason does not like my K7. Images when zooming in are just not as sharp as on my K10 or K5. I discovered this early on, so my k7 is used with other lenses and the K5 gets the tamron lens

You may find it the same, some combinations work better than others, and as long as the limitations of ISO etc, do not interfere go with what works best on each body

[pietro_d]

I will try then also the combinations camera+objective , if it' s the same also in my case.
Thanks for the suggestion :-)