HDR Photography Class Approved

I have approval to teach an HDR Photography class on January 10. The event isn’t yet on the calender. I plan to cover the theory of HDR photography and help students produce their own HDR photographs in the class.

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Steve, looks good - thanks for orgainzing this… Should we register somewhere? I’ve penciled this into my calendar…

Actually, I’m Richard, and I’m happy to be able to teach this class. :smile:

It would be nice for me to know how many people intend to attend, but I’m not going through the formality of setting up registration. Just show up, hopefully with a dSLR and a laptop with either Photoshop or Photomatix or something comparable. I don’t know if the new computer lab will be set up by class time, or if it would have the necessary software.

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opps - sorry - I saw the even created by Steve B and jumped to conclusions…

So Richard :slight_smile: I’ll bring a Nikon D80, and an iPhone 6+. But best I can bring on the software side is GIMP - can you recommend any plugins to download or look for?

You might try this plug-in (I can’t vouch for it, as I don’t use GIMP):

http://registry.gimp.org/node/24310

How familiar are you with the time settings on your camera?

Thanks for the recommendation - maybe I can give that a try ahead of time.

I tend to use aperture mode most of the time. But I have dabbled with long exposure fireworks shots, and I know the D80 has a semi-flexible auto-bracket mode with 2 or 3 shots and exposure increments from 0.3 to 2.0 EV…

Should we plan to shoot in Raw, and consider something other than sRGB? If so, perhaps I should also get the Raw plug-in and a wider gamut ICC profile for GIMP? Any recommendations?

I always shoot in RAW, if that option is available. I create JPEGs by choice only in image editing software, and only if I might publish my image online.

I personally use the Adobe color gamut, because it gives me a psychological good feeling, but I’ve not seen that it makes a difference in anything I’ve done. sRGB is fine.

HDR uses differences in exposure time, and it is best to keep the aperture constant, so the images have the same parallax. Auto bracket is handy most of the time.

I wouldn’t over think it. Adobe RGB is good. Always shoot RAW. To work with
RAW you will need a RAW pre-processor. You should be able to get one from
Nikon to match your camera or it’s built into Lightroom and Photoshop.

The best advice I can give though, is to learn to shoot in manual mode. HDR
is much easier in manual if you understand what’s going on there.

My 2 cents.

Good advice thanks -

Yeah - manual mode is most informative - I learned manual *** some time ago *** on the venerable Nikon Ftn. I suppose I’ve fallen into cheating with auto-mode just to keep some teensy bit of control while still giving a chance to capture fleeting momements…

The whole gamut discussion probably deserves it’s own thread, but it also seems to fit well within a thread on HDR. It’s gotten my attention after trying to print a panorama from an iPhone (ie. sRGB) to the wide format Epson. I understand a ‘perfect match’ is an unreasonable expectation. But I noticed a greater difference than I expected from the Photoshop workspace view, the soft-preview (from the print driver?) and the actual print - especially for the sky blues. Looking closer, I noticed that Photoshop reported some of the blues as being out of gamut - something I really did not expect for an sRGB source feeding into Photoshop and a high end printer. After some research, I have a theory on cause, and I’ve since found setup/workflow instructions from the Epson printer and Photoshop user guides and intend to verify or try those soon. Anyhow, I’m happy to share what I’ve learned, and I’m hoping to speak with somebody who understands it well. I’d like to verify my understandings, level set realistic expectations, and learn best practices…

HDR, as the name suggests, is about dynamic range. It isn’t too difficult to understand, so I feel confident that I understand it. Color gamut, on the other hand, is something that I know about, but I wouldn’t say that I have mastered the topic.

Of course, you want to have control over your color palette in HDR, but that is secondary to the topic.

Color Space - Definetly let me know what you learn. As I understand it,
“shit flows downhill” so to speak.

Color Gamut as a list.

  1. Human Eye
  2. Photographic slide film (low dynamic range)
  3. Photographic color negative film (higher dynamic range)
  4. Digital sensor
  5. Digital display device (I won’t get into Plasma vs LCD and such)
  6. Ink on paper.

As you work from real life, through a digital camera and then onto paper
you lose color shades along the way. What I’ve been told is that if your end
result is a print that setting your camera to Adobe RGB is a better work
flow even though it’s not as high a gamut as other options like ProPhoto.
The reason is that paper can’t support the increase in gamut so you’re
better off limiting the colors in the first place. Shooting for digital
display is a different story.

Also, keep
In mind that monitor calibration and viewing conditions also factor in. The
lights in the room where the printer is are awful. You can’t do a “real”
comparison between print and monitor in that room.

Cool thanks…

I’ll bring a cool book and some other findings on the 10th. So far, it seems that Gamut, dynamic range, color space - all of these terms relate to the same basic concept - ‘what is the span from black to the brightest colors’ - except that sometimes the terms refer to relative intensity values and sometimes they refer to absolute intensity values. It seems that HDR is ‘simply’ a mechanism (or set of mechanisms) to map images or scenes with wider dynamic ranges (ie. larger Gamut) into images or display media with more narrow dynamic ranges (ie. smaller Gamut). And as Steve mentioned, it seems that the whole game is complicated by viewing context and the mechanics of the human eye and perception. Anyhow - cool topic…

Color gamut is a completely separate topic from dynamic range. A color gamut is the color space available for representing images. That usually is described in a hue-saturation graph, that is, each color and how pure (that is, how narrow its spectrum) each color is. Absent from this graph is tone, that is, grayscale range or range of bright-to-dark. Dynamic range indicates tonality.

Many people confuse HDR with tone mapping, which wouldn’t be so bad, but a lot of tone mapping includes options for changing hue and saturation, often resulting in images having stark coloration. This leads to the confusion in the minds of many people (including many photographers) that HDR is synonymous with garishly colored photographs.

You might find the following thread comments helpful:

http://www.dpreview.com/forums/thread/1925708

Color is defined by hue, saturation and tone. Hue is the average peak wavelength of a color; saturation is the range of wavelengths included in the color; tone is the power of the wavelengths. On a graph, hue would be the wavelength at the peak of a color curve (its x-axis position), saturation would be the width of the color curve (across the x-axis) and tone would be the height of the color curve (it y-axis value).

Thanks for bringing up this topic, as it helps me refine my discussion.

You’re quite welcome - thanks for the clarification! I’m looking forward to clean up my understanding…

At risk of dragging this thread into the Gamut weeds…

PhotoShop has been reporting out-of-gamut colors in many of my images, so I’ve been wondering about where to set expectations for printing sRGB space photos (e.g. from generic cameras like iPhone) on the fancy makerspace printer.

I found some ICC profile / gamut viewing tools, and the standard Epson ICC profile for the PLPP 260 paper, and I made this chart to better understand what ranges of sRGB colors might be lost. Does this look about right?

I think your question would be better answered in its own thread. I don’t know enough about specific color gamut issues (such as what a specific printer or monitor would have) to be able to answer this question easily, and I’m not sure I could be accurate in whatever answer I gave. In general, printers will have a different color gamut than monitors will, because printers are subtractive color devices, while monitors are additive color devices. From what I’ve read, pure red will always be out of gamut for printers, because it is impossible to print pure red in subtractive colors. Monitors, though, can display pure red. Inasmuch as you would use both devices to print a photo, you are likely to have out-of-gamut colors somewhere along the way. So, the question is going to be, what device are you trying to match? As I say, though, that’s really not the topic of this thread, and it isn’t something I can reliably answer.

Don’t forget! HDR class this Saturday!