Raw histogram and why does it matter

Your raw data was 2 stops underexposed as shown by the histogram you posted.

If that meets your definition of "perfect exposure" that's fine as it is your choice to make but my definition of perfect exposure is the optimal exposure** which is clearly different to your definition.

* exposure - amount of light striking the sensor per unit area while the shutter is open
** optimal exposure - the maximum exposure* within dof and motion blur requirements without clipping important highlights.
*** under exposed - more exposure* could have been added with the DOF and blur constraints still being met without clipping important highlights.

That question has already been answered so not sure why you are asking again.

I don't have the raw file but we have the raw histogram for that raw file that you posted.

How you add that 2 stops is up to you. If had, you would have ended up with higher quality raw data than what you did and less visible noise.

your assumption is wrong there is no 16000 past "0" EV is clipping

I was referring to the histogram you posted below

and you knew I was referring to that histogram because you posted it in your reply to my post at

dprevived.com/t/raw-histogram-and-why-does-it-matter/1848/post/15814/

So to summarise what I posted:

sorry mate that was from another image. im referring to the dancer i posted with the accompanying histogram. i sent a link to Ian so he could have a play with the image of the dancer not the other one was just a selfie of me .
sorry for the confusion ,its hard with the forum configuration as to what im posting to, its getting a bit confusing.

No problem 🙂

At least now that we are on the same page regarding the histogram I was referring to, I hope the explanation and example in my earlier post give you an idea of the benefits of raw histograms in helping to maximise raw data quality and hence image quality.

Yes totally agree and to be honest I never really think about raw histograms when I am photographing something. It was in another thread that I posted that in my experience knowing that I can safely add up to 1 stop of exposure past where the camera's histogram indicates clipping then I consider the camera's histogram as a close approximation to where the raw data will clip. So for me as well, near as practically possible is good enough 🙂

But I got the impression from DonaldB's op that he was questioning the benefits of raw histograms.

So yes, even though they are not directly in my workflow when I am photographing I, like many of the much more knowledgeable than me members posting in this thread, see how raw histograms can help significantly in maximising the quality of the raw data.

I am hoping, crossing fingers and toes that raw histograms will be an option in the digital cameras during my life time.

Danno

This is just my opinion, but I have noticed on a number of threads you have posted on, that there is a sharp and impatient edge to some of your posts when you don't agree with something. There is absolutely no need for remarks like "It seems you are no more a professional photographer than someone who has picked up a camera for the very first time." - this is nothing but a dismissive personal insult. Frankly, it's rude. Politeness costs very little.

Why not correct the poster's misconceptions (as you perceive them) in a friendly and encouraging tone instead? It would make for a more pleasant read for everyone, including the person you are responding to. There's no need for harshness, it doesn't achieve anything, except possibly making you feel better.

Please don't take this as a personal attack, it's meant as encouragement to build a friendlier community. Happy to discuss what kind of tone is considered appropriate, and for others to chip in, including mods.

@DavidMillier

All valid points and have been dealt with in this post

dprevived.com/t/raw-histogram-and-why-does-it-matter/1848/post/15116/

Please could you send the link to the raw file to us at support@rawdigger.com and we will explain what is happening and why.

Thank you thank you thank you , sent link to you via private messaged

So, in your view, one is either a theorist or an "actual photographer"?

Ah, thank you, good to know. Obviously I'm lagging behind events a it.

Thank you for the file. When you export TIFFs in the "RGB render" mode, autoscaling ("Autoscale to use full 16-bit range") is applied by default. That may be good for previews, but not for analysis, and especially not for clipping analysis.

To switch autoscaling off, please go to RawDigger preferences, "Display options", and switch off "Automatic exposure correction for RGB render" (page 44 of the manual). If raw isn't clipped and the clipping point ("white level") is set correctly, RawDigger will export a 16-bit TIFF without clipping. In this mode, 78 pixels are clipped in Photoshop 255 histogram limit if the RawDigger export is set to sRGB (default), 15 if it is set to ProPhoto RGB in preferences ("Display options" - "RGB rendering color space", page 43 of the manual). Photoshop rounds 16-bit files for the purpose of displaying histograms in 8-bit mode.

If you look at the distribution in ImageJ (a very useful image analysis tool, en.wikipedia.org/wiki/ImageJ ), nothing is clipped in the TIFF, here is the extreme highlight portion:
244 62463 57
245 62719 37
246 62975 34
247 63231 35
248 63487 45
249 63743 25
250 63999 31
251 64255 31
252 64511 13
253 64767 11
254 65023 1
255 65279 17
The 16-bit limit is 65535, but the maximum is 65279, that is lower.

Also, in Photoshop, use "Set foreground color" to set it to 255, go to "Select" - "Color range", choose "Sampled colors" as the mode, press OK, and Photoshop will prompt "No pixels selected", meaning the pixels at exact 255 value are absent or so few and scarce that Photoshop can't isolate them.

RawDigger TIFF export is not of a general raw converter, it is an instrumental one, like the other functions in RawDigger.

I never thought I’d wind up posting this in a photography forum … 😀

It’s worth framing this beginner/expert debate in terms of how novices learn and Vygotsky’s theories of constructivist learning help us. He suggests that learning takes place when the novice is set challenges which lie just beyond present competences but which the novice is ready to learn. He terms this ‘the zone of proximal development’. The novice learns best from someone who possesses the the required skill or knowledge at the appropriate level (or who is capable of simulating this). This he describes as ‘the more knowledgeable (or more capable) other’. Exposing the novice to knowledge outside his/her ZPD will not result in learning - and we can learn from this the ways in which ‘Beginners Questions’ can be answered most usefully by answering at a level just beyond present competence and supporting the beginner to progress.

For further information, try:
www.simplypsychology.org/Zone-of-Proximal-Development.html
which is also a good example of writing at the right level. Or for a full understanding:
Vygotsky, L. S. (1978). Mind in society: The development of higher psychological processes. Cambridge, MA: Harvard University Press

@WolfsHead

That is all true and if this thread was in a Beginners Forum probably more applicable imo. But the op chose to post this thread in Open Talk where imo higher technical discussion is appropriate if someone really wanted to go to that level.

In any case even if we were in a public Beginners Forum where it is difficult to know the range in the level of comprehension of the viewers (both members and guests) more technical explanations or descriptions yes, can some times go way over the head of some of the participants but the flip side is that they can also be very helpful to some of them as well.

In an environment like these forums it is nearly impossible to get balance of technical discussions so that the maximum number of participants will be able to obtain useful information.

But I sense we are going way off topic now but since your point is a very valid concern perhaps it might be more appropriate to continue this point in The Beginners Questions Area thread?