live and learn: GX1 and GX7.ii sensor test

As I have noted before, I am just awful at side-by-side tests. I usually keep a few variables varying, and make changes where I don't intend to. Nevertheless I'm trying again, with a simple goal in mind: seeing with my own eyes what a 16Mpix GX1 sensor can do compared to a GX85 (GX7.ii is my preferred name for it).

So here's my testing setup -

• bright lamp shining on aluminum foil, a few bright objects and a black desk and file holder
• ISO500, tungsten light WB
• Manual exposure at 1/30 second
• Pentax DA40/2.8 shot fairly wide open (no aperture ring to read from - but the setting did not change) and focused at similar points
• framing using "just above a paper clip, top of rocket pen on right edge" precesion
• RAW exposure, opened in Cyberlink's PhotoDirector 8 software, then
• captured with PrtScrn and
• pasted into my favorite tiny graphic processor, LView 1.D2!
• Only the exposure slider was used to adjust between captures

Note that I deem many many issues to not be relevant to this specific test, so I did not work on these!

• specific point of focus
• perfect shooting posture
• absolute center of image
• 'shutter shock' and IS are not factored in - SS should not be a factor at 1/30s but my quivering is another matter!

For sensor capabilities related to gathering light, a bit of blur or imperfect focus won't blow the results to pieces. If they do I am clearly in the wrong hobby (or more precisely: my critics are).

So what did I learn, I asked myself?

First off, base shots and raw settings 'as shot' imported into PhotoDirector 8.

Hmm the upper image "P104" (from Lumix folder P104) has better white balance with the tungsten preset. It's definitely an orange-gold rocket pen not a yellow-gold. The as-shot sliders are amazingly different, but I tried similar settings and the results were definitely worse - so for each camera the choice was a decent one.

I see more detail in the P104 yellow flower, but I believe the focus was about spot on for that shot and further back in the P116 image. Since the results were not precisely the same, no doubt I wobbled slightly in my chair while swapping the lens between two bodies. That's not the goal of this test so I'm fine ignoring the flower details here.

So down to about -2EV we go, to see how the foil and other bright items hold up..

Personally I'd say the upper image P104 has preferable blowout results than P116. Differences are pretty slight though. Looks like focus differs on the far-left paper as well. Thus far P104 is holding a slight edge to my eye.

Upward to -1.3EV now..

Nothing to see here, really. Dark areas behind the foil lack detail in equal measure and the yellow WB bias in P116 gets worse in more light. The foil is a bit more blown out in P116 as well.

EV+0.25 coming next:

Looks like a bit more detail in the darkness now on P116 (lower) image. The flowers are a bit more blown out but I'll gladly take the blame for non-rigorous testing procedures. Heck I didn't even crop the same on every one, how slovenly can I get??

We'll close out with EV+1, since that's as far as my interest held tonight..

Dark areas look great and foil looks awful, pretty much in equal measure.

 = = = = = = = = = = = = = = = = = = = = = = = = = = = =

The results are in! My reasonably rigorous test was really disappointing, in that I feel best about the results from P104 - but my humble GX1 (P116) is not a Godawful DR-crippled pathetic excuse for a 16-Mpx sensor. I might try re-shooting these just to nail focus.. but really neither camera does poorly anywhere in the tests so I probably will not do that.

And in all honesty: as I wrote this I thought P116 was from the newer camera (higher number better, right?) so any bias I felt was in fact doubly blinded! No doubt from the foil.