HDR-High Dynamic Range

Posted: July 14, 2009 in HDR
Tags: , , , ,

HDR_WOU1

HDR is short for High Dynamic Range. HDR is a 32-bit image consists of multiple LDR (Low Dynamic Range) which we can be produced by our camera (Underexposed, OverExposed & normal).

When you merge 2 or more exposure photos into one, the resulted image (32-bit) will not show the full range of tonal representation due to the limitation of our monitor, which can only show in 8/16 bits, a post-process is required to compress the picture. This process is called tone mapping.

To achieve a HDR image, one have 3 options –

The key to choosing a great HDR photo is the extreme levels in light & dark. (It is the kind of photo that one will avoid because you know the end result on photo will never go with what you have seen in mind’s eye)

Next, get your camera (i would prefer RAW ) & Tripod ready, you can set your camera in A mode (recommend by some, although I am not sure why) but setting in S or M mode shouldn’t do much harm. But please do some experiment first to see what which of the setting do to your final HDR photo. Activate your Auto-Bracketing to take -2,0,+2. (3 shots) or -2, -1, 0, +1, +2 (5 shots)….Other equipment needed to take HDR is a tripod-

1) Invest in a stable and solid tripod, it will last you a life time!

2) Shutter release (wired or wireless) this will prevent the picture from going blur when you press the shutter.

Next, get ready your Photomatix Pro, we will open up this  (-2,0,+2) shots in Photomatic Pro. Here are some quick summary to follow before you saeve the HDR photo.

1)leave all option deselected when you are asked under “Generate HDR-Options”. You can play with the options if you wish to

2)Click ok to proceed and wait for a few mins for Photomatix to process. Once you see the photo ( you wont be able to do anything with it), click on “Tone Mapping” and Photomatix will bring you to a new window with sliders. For the function of each sliders and what they do, you candownload the PDF below.

PhotomatixProManual

Once you are done, save the final image in jpg and open up in photoshop. OK, i had listed a summary of items we will do using Photoshop.

1)Import all the 3 original photos (-2,0,+2) & the JPG from that you saved earlier from Photomatix. So you should have 4 images in the Photoshop layer. (if you wish not to import all, select the darkest of all photos cause you will need it next)

2)repair all blown-out area using the darkest of the original image using ‘mask’. You will need masking for the original blue sky in Photoshop as HDR processed photo will render the blue sky grey, not pleasant to the human eye.

3)put the HDR photo on top layer, and stacked the less below, from darkest to lightest. Once you become more advance, maybe just one or two will do the trick.

Bonus – to get #3 done, do the following. Open all photos, you should have all open in Photoshop under different windows, choose your orignal RAW photo (this will be your base layer). Goto another window, goto select -ALL, The Edit – COPY, now go back to your base layer, do a Edit – Paste, then you end up with 2 layer in photoshop. Continue this until all in. (so the HDR photo will be on top)

4)select all layers by CTRL or SHIFT clicking them, then under the Edit Menu, select AUTO ALIGN

5)now, we are into masking, the idea is to remove the top layer (HDR) so a see through hole appear on top layer, allowing one to view the underneath layer.

6)Click on top layer (HDR), on the MENU, go to Layer>Create Layer Mask>Reveal All

7)choose brush tool, adjust OPACITY to 30-40%, next set the Brush setting to brush size 100

8)now that you had create the MASK (white box on the right of image), start using the brush on the photo.

9)after you are done masking, Merge Layers in the menu

There you are done 🙂

I had posted herehere , here & here –  some of my HDR sample, check it out.

For those looking for a video on Photoshop Masking, you can check out this video from Youtube.

For those looking for a video on HDR How-to, you can check out this video from Youtube.

They are a few photographer/artist (Andy Calnan & Trey Ratcliff) who had done remarkable  job in HDR, check them out too

* thanks to Andy from http://clamroll.wordpress.com for kindly sharing and pointed out another available option in creating HDR image.

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Comments
  1. Andy Calnan says:

    Hey thanks for putting me in your blogroll! If you want another great resource on how to HDR, check out stuckincustoms.com, it’s where I learned most of my tricks! Id suggest trying Lucis too, I like it more than photomatix

    http://clamroll.wordpress.com

  2. momoc says:

    good explanation and easy to understand for a beginner

  3. iqqiVR says:

    Fantastic! Now I can share the knowledge with my kids… 🙂

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