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Re: [OM] After the Sunset - An experiment in HDR with a spot meter

Subject: Re: [OM] After the Sunset - An experiment in HDR with a spot meter
From: "Jim Nichols" <jhnichols@xxxxxxxxxxxxx>
Date: Wed, 14 Sep 2011 22:13:14 -0500
Hi  Ken,

Interesting reading for one who likes the E-1, and is too tight to spring 
for the 5D or 7D.  There appears a lot of life left in the old girl yet!

Jim Nichols
Tullahoma, TN USA
----- Original Message ----- 
From: "Ken Norton" <ken@xxxxxxxxxxx>
To: "Olympus Camera Discussion" <olympus@xxxxxxxxxxxxxxxxx>
Sent: Wednesday, September 14, 2011 8:24 PM
Subject: Re: [OM] After the Sunset - An experiment in HDR with a spot meter


> Well, just completed round one of DR comparison. I converted everything
> exactly the same way (flat, zero corrections of any kind) in Picture 
> Window
> Pro. Yes, it's pretty brutal in the uncorrected format, but that's what I
> wanted to see here.
>
> Out of entertainment we shot the 7D at 100 and 3200. I've got an 
> observation
> about this. I'm not aware of the 7D pulling exposure for ISO 100, but 
> there
> was an apparant DR hit on it. We may retest at ISO 200 to study this
> further. Regardless, Canon definitely fixed the color and dynamic range
> issues with the 7D. I'm quite impressed with the ISO 3200 tests. I can 
> tell
> there is a lot of noise-reduction going on with the 7D's 3200 setting
> because the bottom end was lifted and the top end supressed. Inotherwords,
> the noise is being masked in-camera (even on the CRF files) and then
> noise-reduction is actually extending the useful dynamic range of the
> image!!!
>
> Of major interest to me was how the venerable E-1 stood up to these two
> cameras. Just as I expected, the top end takes a hit. But so did the 7D at
> ISO 100. The 7D at 3200 almost perfectly matched the 5D's dynamic range at
> 100, but at ISO 100 it was almost a dead knockoff to the E-1. The 
> grayscale
> portion of the IT8 target looked like this: (no highlight recovery 
> performed
> at all on these 3-stop overexposed images--that's coming next):
>
> Last easily identifiable Gray patch on the scale:
> E1 - 12
> 5D - 9
> 7D (100) - 11
> 7D (3200) - 10
>
> But where things get interesting is in the colors. I'll list out the 
> number
> of visible boxes stacked in each color:
> E-1 - C 4, M 3, Y 2, K 6, R 5, G 5, B 5
> 5D - C 5, M 4, Y 5, K 7, R 6, G 6, B 7
> 7D (100) - C 4, M 3, Y 3, K 6, R 5, G 4, B 6
> 7D (3200) - C 5, M 4, Y 4, K 7, R 6, G 6, B 7
>
> The bottom end is a little inconclusive, as 2-stops underexposed was 
> easily
> handled by all three cameras, but there appears to be some interesting
> trends. The Canons have a tendency to increase saturation a bit in the low
> levels--especially the blues as they turn more purple. But the biggest
> thing I noticed was how the E-1 tended to go darker in the mid-lows but 
> then
> leveled out more near the end. A classic "toe" response curve. All of them
> maintained visible steps all the way to the final square.
>
> So, that meant I needed to look at something else. In the lower-right 
> corner
> of the IT8 target are six squares of similar colors which really really
> tough to get a good response on. None of the cameras correctly captures 
> J20
> or J21. J30 was too dark on the E-1 and the 7D at 3200. But all did a 
> pretty
> comparable job.
>
> So, basically here is my initial conclusion in this first-draft rough
> and dirty comparison: The 5D and E-1 are in different leagues when it 
> comes
> to the top end of the dynamic range. The 5D is around a full stop better 
> off
> there, and most importantly, right near the top (when the sensor starts to
> clip), the 5D does maintain a lot more color accuracy. Yellows are
> particularily a disaster zone with the E-1. Even the gray scale starts to
> change colors near clipping. The middle-range of tones is where the E-1
> really shines and you can see how the bottom end and a curved response.
>
> The real suprise to me is the 7D's performance. At ISO 100, the dynamic
> range is hardly better than the E-1's. In fact, it experiences similar 
> color
> shifts as the E-1. But the ISO 3200 setting of the 7D revealed curves very
> much like the 5D's at 100.
>
> The premise behind this specific test and raw conversion was to first of 
> all
> generate some HDR profiles for PWP. As such, the conversions were kept
> perfectly straight with no shenanigans performed. Also, they were done 
> with
> the converter engine in PWP, which is DCRAW based, I believe. I'll do some
> additional conversions using ACR and Olympus Studio, which I know is 
> better
> behaved on the Olympus files. I will also do some highlight and shadow
> recovery on these files to see what is really lurking in the extremes.
>
> I'm quite impressed with the 7D (as I've always been) and find the 
> high-ISO
> performance to be quite admirable. But it is nice to know that the E-1 
> isn't
> quite the dog that the world has declared it to be. Just do not overexpose
> it.
>
> AG
> -- 
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>
> 


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