Sunday, July 29, 2007

Olympus E-510 vs. Nikon D70 for UV

I got an Olympus E-510 for a few days and made a quick test tonite with that flower I shot using my D70 a few days ago.

The preview function is quite nice, since it allows quite nice focusing I have to admit. The Ergonomics I had to get used to, quite different that the Nikon.

But all that was not really the subject, I was more interested in the sensitivity for UV; let the result be revealed right now, from my test that would be -4EV as compared to the D70. I also noticed that the tonal range of the E-510 original files (I shot Raw+Jpg simultaneously) is more limited than those of Nikon, but the interesting thing is, that the blue channel of the E-510 seems to be the most UV-sensitive one, whereas it is the red for the D70. The images of the E-510 without any correction look much more "natural", though, since they appear violet/blueish as compared to the very red ones of the D70 [since shooting UV images, a violet/blue tint just feels more "normal" for UV than red images - of course that is nonsense since for humans UV has no "color" at all].

I have developed a process to tone the UV images, so as the tips of the Mexican Zinnia appear in about natural yellow tome, the rest adapts to that (brownish/reddish). Since I used that for the D70 images I adjusted the ones from the E-510 accordingly for easy comparison.

Comparison Summary of Nikon D70 and Olympus E-510 for UV

Target: Mexican Zinnia, ca. 12mm flower head, so the following images are ca. 3x magnification

Lens: UV Rodagon 5.6 / 60mm
Flash: Nikon SB-140 w/o SW-5UV
Filter: Baader 2" U-Filter
- D70: 140mm,
- E-510: 105mm (since the form factor of E-510 is 2, D70 is 1.5)
Left images: Nikon D70
Right images: Olympus E-510 (resized / cropped to D70 size, due to the larger 10Mp format of the E-510; D70 is 6Mp)
- D70: ISO 400, f11
- E-510: ISO 800, f5.6 (there was no other chance to get somewhat normal exposed images)
subjective evaluation: E-510 image still underexposed by -1EV as compared to D70

---> UV sensitivity -4EV as compared to Nikon D70

A shot from that test, first taken with the Olympus E-510:

Now the one using the Nikon D70:

Here now a side-a-side comparison, Nikon on the left, Olympus on the right side:

Oh, and yes, I bought it finally, since liveview makes live esp. for macro shooting much easier even if it doesn't help much for UV or IR....

Stay tuned, more will follow on that subject...

More info on this very interesting field may be found on my site>