Originally Posted by mdarnton
In order to better understand what I was seeing, I loaded the Chrome browser with a histogram viewer that displays histograms of photos on the web with a right click. Yesterday I was going through one of the Monochrom threads I noticed something that was pervasive in photos from many different photographers, and I'm wondering about it.
Many of the histograms display regularly spaced missing values on the right half, regularly spaced spines of peaking values on the left half, and a strong zero value followed by the first four or five values being completely empty, then a small spike, then another, smaller, complete gap, and then a normal histogram. This pattern does not ever display with photos from other sources, so I'm counting it as a Monochrom peculiarity, not something about the browser plugin.
What I'm wondering is the cause. Is it some common conversion software that many people are using for dngs, or is it something with the camera's internal brain? The pattern is remarkably similar across users, but not inevitable, so I'm suspecting some common post-processing glitch.
I use Heliopan 2X yellow filters marked "Digital." I discovered that the filters marked "Digital" have built in IR and UV filtering so that basically noise that does not add to IQ is removed from the histogram. This also increases the signal to noise ratio and the result is that one can shoot more to the right (increase exposure) and create cleaner files with a broader distribution utilizing all ten zones.
I found out from Michael Reichman's review of the Monochrom that Leica engineered the Monochrom to be uses with a light yellow filter for panochromatic response. The yellow filter I find hits the sweet spot of the sensor, and I find that when using a yellow Heliopan filter marked "Digital" that I'm able to capture the most data and produce the broadest histograms that display proper contrast without the need of much post processing. Basically I minimize post as much as possible.
Much of my technic is to think like a large format shooter who is trying to maximize information for contact printing, so the idea is to do everything right at the time of image capture. I do not think most are thinking or doing what I am doing, and most are conservative with their exposures to not blow highlights and are relying on post processing to bring out detail.
I'm thinking the histograms you are seeing are where the exposure/signal is compressed, rather than broad and open like mine.
BTW getting rid of both the IR and UV minimizes or eliminates clipping so some of those bumps to the far right might be some of that signal that is really just noise.
Know that with the Monochrom if you have the detail in the shot and perfect technic you can approach large format tonality and IQ. Not hard to do with the ten zone histogram display and the clipping indicators set at 1% an 99%.
Perfect exposure is easy because basically the histogram provided by Leica does not lie, and most shooters IMHO are not trying to maximize data capture at exposure and rely on post to rescue data. If you print really big, you want to minimize digital artifact and noise as much as possible. I see a broad midrange, mucho shadow detail and a lot less contrast in my images. On my prints I get asked if my Piezography prints are silver wet prints all the time.
"You can't print what's not there," my friend Steve once said.