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| The Car Ferry, Pocahontas, crossing the James River in SE Virginia near Jamestown (click to enlarge) X-T2, 100-400mm lens @ 203.7mm; 1/500th sec. @ f/6.4; ISO 200 |
While performing a test of any measurable EVF brightness differences between my X-T2 and my X-T1, I discovered the light meters on the two cameras gave me different readings under identical conditions. Hmmm? What should I make of that?
If you look at my last post, you can see how I had the testing procedure set up to have everything between the two cameras set identically. If you missed it, you can read it here..
When I discovered the two cameras' meters gave different readings in this bright light environment, I ran some additional tests to see if that held true in environments with lower light levels. It did. In every test I made—bright, medium light and low light—the differences were exactly the same.
What were the differences?
In matrix metering the difference was 1 full stop. That is significant. Difference in metering programming? Could be.
In spot metering, the difference was 2/3 stop. Less significant but noteworthy.
In average metering, the difference was 1/2 stop. Again, noteworthy.
Consistently, the X-T2 showed metered exposures that indicated a higher shutter speed or smaller aperture was necessary than with the X-T1. That tells me that the meter in X-T2 saw brighter conditions than the meter in the X-T1, when they were exactly the same level of luminance.
I didn't use calibrated light sources, but the tests were consistent. Everything was equal as far as I could make it without going into a lab and setting up a highly controlled experiment.
What do you make of it? Was this particular test an anomaly? I don't make anything of it yet. I use the histogram to set my exposures so I don't necessarily rely on what the light meter is showing me. But as I use this new camera I will assess if I believe everything is working and calibrated as it should be. I'll let you know if I find anything else interesting.
Thanks for looking. Enjoy!
Dennis A. Mook
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there was the issue of x-t1 iso actually being correct - if the x-t2 corrected this, then obviously the metering would be different.
ReplyDeleteI have the X-T1 and I often have to dial down the exposure to preserve the highlights. Even in RAW I otherwise have blown parts in the image. So to me it sounds like the X-T2 measures more accurately / conservatively.
ReplyDeleteI'm having issues with my x-t2 undexposing when the x-t1 would nail it. Kind of annnoying.
ReplyDeleteInteresting. Just to make sure, was your DR setting the same on both cameras? (DR100, DR200 or DR400).
ReplyDeleteI don't have the X-T2 but I do have the X-T1 and, yes, I do notice if often have to play with the exposure compensation to bring it down a bit.
Indeed, they were set identically. Thank you for your comment.
DeleteSurely, cameras with different sensors will need different exposures. What's the fuss about?
ReplyDeleteFunny! Thanks. 😀
DeleteActually, I wonder myself. Sony designed the sensor for a Sony AA-Filter and a Sony CFA; so one might assume that the gain of the LNA and the linear range of the ADC are designed with Sony in mind. Often, hardware level programming like that isn't software changeable, you can select ISO levels, but you cannot change the gain associated with them.
DeleteFuji could "attempt" to get it right by displaying a different ISO than what they tell the chip to set it as, which could account for why they have "Issues" with exposure consistency.
(But I really haven't read the datasheets for these sensors, so I could [and probably am] be completely wrong)