The benefits of criticizing


This blogpost has nothing whatsoever to do with colormanagement or editing. It originated purely out of frustration and bewilderment of the online photo community. You might call it a rant, and it should be read that way: Take it with however many grains of salt you like.

“Great Image”

… That’s a phrase I see quite a bit variations of when browsing photo sharing sites and forums and, lately, Twitter.
All to often though, I look and the image and think: “No, it isn’t great”. Heck, in some cases, the image isn’t even what I’d call “good”.
Why these comments then? It might be because people don’t understand the value criticism can have and want to be nice…
Well, guess what: In my opinion, about the worst comment someone can make about my photos is “nice image”: I know it’s “nice”, otherwise I would not have posted it. But I also know it isn’t perfect. In fact, I can pretty much guarantee that I see flaws myself in every image I make. I see them, and because of that I can hopefully avoid them next time. But because I’m not perfect, I might overlook other flaws. Since I want to continue learning, I’d like to have them pointed out: I prefer input over praise.

What’s criticizing then?

Read the rest of this entry »

Pixels per inch for web

What is the significance?

Simply put? Nothing.
Well, if that were all I had to say on the subject, this would have to be my shortest blogpost ever… Okay, a bit more info then:
A lot of first time DSLR users are concerned that their shiny new camera delivers files that are “only” 72dpi, while their old point and shoot delivered 300dpi files. Why is this concern unwarranted? Surely 300 is more then 72, and more is better, right?


The old wisdom saying is that “300dpi is for printing and 72dpi is for screen”.
There are a few things wrong with that.
First and foremost, the term “dpi” stands for dots per inch. In a digital file there are no dots, only pixels. So the correct term is pixels per inch (ppi).
Also, 72ppi originated as it was the resolution of an ancient Mac monitor. Current monitors have a much higher pixel density: My old 12″ PowerbookG4 for instance has a screen resolution of about 100ppi. Most current screens are somewhere between 80 and 120ppi.
Read the rest of this entry »

Clipping Warnings in Lightroom

And why they deceive you

Adobe Photoshop Lightroom, like many other Raw converters, has a clipping warning.
The purpose of it is to give you a visual warning (apart from the histogram) of what parts of an image might be clipping.

What is clipping?

A pixel is clipping when it reaches a value of 0 or 255 in one or more channels, and “should have gone further”. Since it cannot go lower then 0 or go higher then 255, it remains at those values: Detail is lost if one or two color channels clip, part of the image is solid black or white if all 3 channels clip.

The effect of color space

As with anything in digital imaging, the color space used has a big influence: A wide gamut color space (such as ProPhotoRGB) will have lower values for the same color then for instance sRGB. So a color that is clipping in sRGB, need not be clipping in ProPhotoRGB! Read the rest of this entry »


How to see what you’ll get

for a web gallery.
Normally, Lightroom will only let you preview sharpening and noise reduction at 100% view. This is a good thing™ in my opinion, since it is capture sharpening, meant to negate the effects of an anti-aliasing filter in front of the sensor. You’d get all kinds of moiré without an AA filter, as can be seen in the hilarious story Eamon Hickey wrote about the NC2000.
Since the AA filter softens the image a bit, you need to sharpen it. This is input sharpening. So it should be judged at 100%. Unlike output sharpening, which is better judged at reduced size, at least: For print. For web view at 100% and WYSIWYG.
Or is it?

A workaround

I recently was processing a few ISO 6400 images, which had severe noise in them. Here I ran into the problem that the NR isn’t shown at “fit window” view. So I had no way to judge what the images would look like online. Read the rest of this entry »

The world wide web

and color management

A lot of people are confused the first time they save an image for web display: The image looks different in a non color managed browser then it did in Lightroom or Photoshop. One “solution” was to view the image in Photoshop like it would appear in a non color managed application, by going View > Proof setup > Monitor RGB. This would show you how the image would look in a non color managed application on your screen. Still a guess what anybody else would see though, since you’re seeing the difference between the monitor profile and sRGB…


A much better option would be for everybody to browse color managed.
Up until recently, most browsers were not color managed. Safari changed that, and was the first color managed browser for PC. Internet Explorer had provided a color managed browser for Mac OSX before that, but it is discontinued now.
Read the rest of this entry »

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