Blown or not?

[ShutterbuginAZ]

I feel as though I know enough to produce an image that is a notch above the average snapshot and I am eager to take it to the next level. I understand that I am not a pro. I just want to get as close as I can to a "correct' image that my limited equipment will allow. I have seen comments where a forum member will be discussing whether an image is blown or not. They have used a number to determine this. Can anyone give me any more info? I have access to my son's photoshop CS2. Are the little boys socks blown? If I look hard enough I can see some detail.

[jfrancho]

If no one gets to this, I can show you a few methods later tonight.

[harryd]

Pamela I am not an expert but I think I know what the numbers mean. This is a CMYK image, first then open the WINDOW > INFO panel. Get the eyedropper and move it over the image and as you move over the image you will see the CMYK numbers change (Top right box in the Info window) and pure white shows 0% in all 4 CMYK channels which your sock shows.
I prefer to work in RGB channel so I converted the image to RGB, it works the same way but it is the top left box in the Info window, 255 is pure white which your background is, also there is a place on the sock that also shows 255 in all three channels of R G B. The entire sock is not blown out just a part of it if I am doing it right.
I hope this helps and if I have done it wrong I hope someone corrects me.

[Lee4145]

What Harry describes is how I check too. But in this case, if it were mine, I wouldn't sweat blown whites on the socks. The face looks good. I'd be happy with this exposure and conversion.

[Jeff M]

Originally Posted by Lee4145

What Harry describes is how I check too. But in this case, if it were mine, I wouldn't sweat blown whites on the socks. The face looks good. I'd be happy with this exposure and conversion.

The sock isn't completely blown so I wouldn't worry about it.

It does look like you could use some levels adjustment to get the back level closer to the left of the histogram. It adds some more pop to the image.

I hope you don't mind but I did a quick level adjustment, bringing the black point just to the edge of the histogram.

[ShutterbuginAZ]

harryd - Thanks so much for the lesson. The best part is that I actually understand what you were talking about

Jeff M - Like your edit. I love the look of black and white, but my conversions are hit or miss. Although I was happy with mine...I would pick yours over it. Thanks!

Lee4145 - Thanks for the comments. This little boy was all about big, fake smiles until I put my camera on a tripod and used a shutter release cable. I worked pretty hard for a natural smile...so I was very happy with the outcome. Thanks again for commenting!

[jfrancho]

Hello Pam, as promised! I will show you a couple of things to analyze your images, and offer some final thoughts.

You question was whether there were blown highlights. Well, yes and no. I'll explain.

I took the liberty of opening your image in Photoshop CS2 (yes, I still use it, just haven't made the switch) and the first thing I look at is color space and mode. Yours opened in Dot Gain 20% in Grayscale mode. I would convert this back to RGB mode (Image > Mode > RGB), and convert to sRGB IEC61966-2.1 (Edit > Convert to Profile...) if your inentions are geared toward a web presentation. Now I have the image in the best working color space and mode.

The next thing I do is check the histogram (Windows > Histogram). It will look similar (I use a customized desktop, but it'll be in the upper right) to this, showing a graph representing your image. The dark values on the canvas are on the left, the lighter are on the right.

CLick to link to full res screen shot


If you look close, you see the histogram bunched to the right, and looks as if it would spill over to the right if the chart went further. It doesn't. Colors are represented in RGB mode by a value of 0 to 255. 255, 255, 255 is pure white, and 0,0,0 is pure black. The stuff at the right is at 255, 255, 255 and is indeed clipped.

It actually looks like a lot of the image is clipped, with much of the image data bunched to the right. That's because its a "high key" image. High key means a properly exposed subject on a light, white background. Describes this perfectly. So, now that I know that there is highlight clipping, I want to know where its clipped. Maybe its just in the background, which probably doesn't matter too much, though I prefer to avoid this.

I add a Threshold layer, by clicking the little half moon New Adjustment Layer icon on the layers panel:



This will bring up a dialog box with a histogram and a slider. Slide it all the way to the right to show us where the highlights are clipping, and click OK. The areas that are white are clipped. Those in black are not:



So, there is a tiny bit of clipping in the sneakers and the socks. I'll get to that later. Now I want to check the shadows. There wasn't any spillover to the left of the histogram, so there isn't any clipping in the shadows. But I want to know exactly where the lowest values are, and take a measurement, using the Color Sampler Tool.



To check the other end of the image, or the shadows, double click the icon between the eye and the white rectangle (this is the mask - whole other story), and the dialog will reappear. Now move the slider all the way to the left, until the image turns white. Don't click OK yet, instead gently slide it to the right until some black spots show up. Then click OK. Like this:



Next, zoom into to blow up the image to 400% (Ctrl - +), and make a few clicks with the Color Sampler Tool in the black spots. You get a maximum of four samples. If you need to move the image around, hold the space bar down and you'll get a sticky hand that you can use the mouse to move the canvas around.

Make sure the Info Panel is visible - if it isn't, use Windows > Info to activate it. Take a look at that panel. You can see the samples I made, and their values. All three channels - R, G, and B - will be equal. They should, there's no color. anything with the same RGB values between 0,0,0 and 255,255,255 is a shade of gray. Click the eye to the left of the Threshold 1 layer to hide it. You can delete it using the trash can button if you want. Cool?



Back to the Info Panel. You can see the three samples show 25, 23, and 27. That means they are more than 0, and not absolute black.

So, the image has very slight subject clipping in the highlights, and no clipping shadows. Here is my take on all this. There are only 255 shades to work with in a digital B&W image. You want to use as many of them as you can to portray your picture in the best way. The background being totally white is no issue. It only is if it is so blown, that the edges of your subject get lost in the blowout. The slight clipping on the sneakers and socks? No sweat, leave it and be careful next time. If you shoot in RAW mode, you could very easily use the Exposure slider to recover those highlights, but it isn't even worth the trouble.

Now, on to why Jeff's edit looks so great - with tons of pop. Instead of just using some of the shades gray, starting around 25, you want to get that darkest spot as close to zero as you can. Use that New Adjustment Layer button, this time click on Levels... and grab the slider and slowly slide it to the right, while watching the values in the Info box. The values will look like 27/14. The second number will drop as you slide to the right. Pretty cool? Get that value down to around 3, and your image will like Jeff's.



Now there a few other ways to do this, the obvious choice is to simply click the black eyedropper in the Levels Dialog and click directly on your darkest Color Sample. The other is to use Curves. Same idea, different mindset,and different skill set. I like the visual aspect of using the slider to drive the point home for a beginner of advanced Photoshop (nice twist?).

Try it your self!

[ShutterbuginAZ]

jfrancho - No wonder you had to wait until later to respond. What a detailed response. Thank you so much. I have printed out your post and will use it for a "how to guide." As I mentioned my conversions were "hit or miss" and now I see why! I was taking the easiest route possible to get there. Can any member give Karma? You and JeffM sure deserve a karma (or two or more) for posting such detailed, helpful posts. Thanks again!!!

Completely off subject. I used to live in Rochester. Do you worry about all that humidity ruining your camera equipment? I live in AZ now...I only have to worry about the 118 degree temps. I can't leave my bag in my truck for any length of time. Just teasing about the humidity...thanks for your helpful response!!!!!

[jfrancho]

You can karma anyone you'd like

Camel Karma - Tutorial

[bobbyz]

Question - Can't you just use the level tool and then hitting the alt key on PC would show whether blacks or white are clipping?

[jfrancho]

Originally Posted by bobbyz

Question - Can't you just use the level tool and then hitting the alt key on PC would show whether blacks or white are clipping?

I'm not sure I understand. What is the level tool? If there is an easy way, please share

[jfrancho]

Do you mean alt clicking the slider in the Levels adjustment dialog? You threw me with the term "tool." yes that works, and as I said, there are many ways to skin a cat. The difference there is that can't see the actual values of your samples, so its just as effective, but offers less data. I am a numbers guy, and I like to know that my highlights are no higher than a certain point, and no lower than a certain point. This stuff becomes more important if the output destination is print. Thanks for that bit - I guess I'd have to make a video of the to demonstrate, since PrtScr won't capture that at activity at all.

Incidentally, the alt-click slider does many things in many areas of Photoshop, so try it out to see where it works. My personal favorites are alt ckicking the Exposure and Shadows sliders, as well as the CA sliders in ACR.

Thanks for poitning that one out

[felix.reichardt]

Its a VERY nice portrait.


(I could not care less if the white in the socks are blown , it's not important because it's not obvious (at least to my eyes).)

[ShutterbuginAZ]

This is an old thread, but was hoping I would catch JeffM's attention. I have been playing a little with my conversions (have a few days off soon and plan to devoted some serious time), but I have yet another question for you. Did you also so some sharpening when you bumped the contrast? Looking at my image and yours it is plain to see that yours is much sharper. If you did sharpen it..I would love to know what method you used...if you have the time. Thanks so much!

[bobbyz]