How to get the best raw exposure, part 2

Exactly, nothing wrong. Why turn Jim's thread into something this ugly, why try to discourage bringing in some light - no idea.

Oh the irony

I kind of figured that, I wanted Don to figure out as to why he is seeing what he is seeing by pointing him in the direction that how FRV was setup was giving him the results he was showing

I find it funny as how all this grief and snark remarks we now have come to another point in your learning. I would take the time and listen to what people have been saying all along

I find that most are not, once you understand how to achieve the results for the camera you are using it really is not that hard to carry it over to most of the situations you work in

Im sorry but you made the remark that my zebras were 0.67 of a stop out which was incorrect. my in camera zebras where showing the exact number of clipped pixels . nothing was applied to my images period. Illah discussed what the figures were and how they were or were not applied. In fact history has been made. that the sony cameras zebras and incamera histograms couldn't be any more accurate.

It was a great thread. everyone has come out with more knowledge from both sides. win win, wish all the personal bashing would stop though, it is what it is, cant wait for threaded view.

I only ever defend my self nothing more. I dont just drop in and personally attack someone when they are in the middle of a good discussion.

Hmmm:

so 500 lux for 1/100 sec = an exposure of 500.01

and 500 lux for 1/50 sec = an exposure of 500.02

Some might not think so ... 😉

I'd much rather see DonaldB and Danno take this thread to 2000 posts than see another user moan on and on about the idea of having civility in these forums and characterize such an idea as an attempt to "pansify the world".

Be careful of what you wish for 🙂

One of my wife's Mother's Day presents this past Sunday was some potted red flowers, I took their appearance as an unmistakable message from the forum gods that I should go ahead and do a red flower test of my EM1iii's live (luminance) histogram and highlight warning blinkies. Contrary to Donald's results with his magical Sony cameras, my test results confirm that my EM1iii's live histogram is based on the RGB data that generates in-camera display and JPEGs. The real difference between my results and Donald's has nothing to do with the different cameras used and everything to do with different scenes tested (and resulting highlights in the respective color channels). If Donald were to perform a similar test with his Sony cameras on a similar red flower scene as the one I used, his Sony cameras would no longer display luminance histograms that seemingly magically match the corresponding raw histograms. Here are my test results:

With 0 exposure comp. the live histogram (upper left) is pushed well to the left and looks like there's absolutely nothing approaching clipping. However, the post-shot in-camera RGB histograms (upper right) show that the red channel is pushed well to the right but just short of clipping. In this scenario, the live histogram does a dangerously poor job of predicting red channel behavior in an in-camera generated JPEG shot. And as can clearly be seen from the FastRawViewer screen grab, the live luminance histogram looks nothing like the raw histogram either, which in turn looks pretty different from the in-camera RGB histogram. The only good news here is that, at least, only a measly 3 red pixels were clipped. The bad news is that there's a significant amount of blocked/underexposed blue pixels in particular.

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The above collection of screen grabs is for the same scene shot with +2 EC applied. Not surprisingly, the live histogram is pushed farther right but still shows plenty of breathing space from the right edge of the histogram. So, no clipping, right? Wrong for the JPEG and just barely wrong for the raw. The 5k clipped red pixels in raw can easily be addressed in conversion. However, the JPEG red channel clipping means that any attempt to pull back image lightness in postprocessing of the OOC JPEG will result in a color shift toward orange/yellow for the clipped red pixels. Note also how nicely the luminance histogram matches the green channel in the in-camera RGB histogram and also the green channel in the raw histogram...but ONLY the green channel. There's no way to argue that it matches either of the other raw channels or a combination of the three raw channels.

The above collection of screen grabs is for the same scene shot at +2.3 EC. Everything looks similar to the prior shot, as you'd expect from the mere .3 ev increase in exposure. I've included it here though because this is, for me, the best ETTR'd shot I took within the 3 stop bracket of 1/3 stop increments. Although 5.7% of the red raw pixels are clipped, they're speckled and scattered across the flower petals and not clumped together in a way that leads to visible color shift or that flat, textureless color clipping we always dread with red flower shots (viewed with a narrow gamut display/print). With careful conversion and maybe a bit of postprocessing trickery in Photoshop (e.g., channel blending), means that these pixels can be sacrificed for the noise and shadow improvements to be gained in the blue channel (which still has some blocked pixels). However, I suspect many ETTR shooters would not want to venture beyond the more conservative +2 EC shot. Different priorities, different workflows and skillsets...

The above collection of screen grabs is for the same scene shot at +3.0 EC. It's noteworthy for a couple of reasons. First and foremost, it still looks like the live histogram hasn't quite bumped up against the wall (likewise for the post-shot RGB luminance histogram). However, the first hint of a highlight warning blinkie is visible right in the middle of the white stigma. Things are also getting messy at the raw level. 30% of the red raw pixels are blown and that means there will be some significant color shift to the orange/yellow side of things in much of the flower. The green channel is also starting to get into the clipping game as well. This version is just living life too dangerously. Final note: still no good match between the live luminance histogram and the raw histogram. Of all of the individual channels, the best match to the live luminance histogram continues to be the green channel from the in-camera RGB histogram. Hmmmm...now what does that tell us about what is the primary driver for the shape and position of the live luminance histogram???

The above are quick dirty renderings of the 0 EC, +2.3EC and +3 EC shots done in ACR with roughly equalized lightness applied via highlight, shadow and exposure slider adjustments to illustrated the respective tradeoffs in shadows, highlights and color shifts.

I'll be out of pocket for several days, but I hope this might stimulate some legit discussion that gets the thread back on track. Unfortunately, I probably won't be able to reply to questions/comments until next Sunday.

your testing method is not going to be accurate because the red channel is not going to be the same colour red , i shot a red lunch box and my in-camera histogram was pretty well spot on .given the colour red is a mix of rgb colours. i might be wrong ,but someone more experienced might chip in.

You are presented with a real world result.

It's a good idea to study Bill Claff's dynamic range graphs too. I don't think your FF camera has to be made by Sony.
But it does seem that in general the larger format sensors have greater dynamic range.

Don Cox