Tag Archives: threshold

Sneaky Night (and Daylight) Photo Processing Tips

 

Did you attend the Sneaky Night (and Daylight) Photography Processing Tips event held at Adobe in San Jose, California on July 23, 2018? Welcome!

The topics covered include these:

Let’s Start With a Pop Quiz

The Equation…

Or asked another way. Do these look like they might be the makings of an interesting shot?

Three Nuns Thumbnails

The Answer To the Pop Quiz

Combining the images shown in the thumbnails, nets this Interesting star trail.

N-604259-361lstr

“Long Streaks” Star Trail from 112 separate photos

Creating the Star Trail component above is discussed in detail in our NP105: Creating Star Trails & Timestacks Webinar – it’s an interactive 2 hour course with notes, a recording, and practice files. We run that webinar approximately quarterly next event is July 25th. Details  covered include how to set up the shots, configure the camera settings, and combine the images using various tools.

Adding that bright frame with a bit of selection and masking to the star trail image nets this:Reaching for the Sky

And that MUST be interesting because it garnered 80,000 views in just a few days. How do you do this bit of Photoshop Magic? Over the years, we’ve shown quite a few methods for accomplishing this. For example in Foreground – o – Matic we illustrated how to use the quick selection tool. That may work well here because the rock has a nice crisp boundary. Other methods that may work include “thresholding” and Color Range selection.

Thresholding to create a mask:  We’ve described this before. Briefly this is how it works. Select one of the images – one with contrast between the sky and foreground.  Duplicate that image (Ctl/Cmd -> J). Then use Image -> Adjustments -> Thresholds and slide the carat left or right until it has selected what you want (mostly black or white). Paint out the stray areas with either a 100% black or white brush as appropriate.  When done, you have an image you can use as a layer mask. The trick to doing this is to select the black and white image, EDIT an existing layer mask, and paste the black and white image as the layer mask.

 

Photoshop Processing Tips

  • Do work on a calibrated free-standing display in a dim, consistently lit room.
  • Do NOT attempt to process important images on a laptop monitor. You will frustrate the dickens out of yourself trying to get consistent color, brightness, and so forth on a laptop monitor or in an uncontrolled lighting environment. The monitor display angle can cause subtle to dramatic differences in color, saturation, brightness.
  • Do make an action and assign it to a hot-key if you find yourself repeating that operation frequently… E.g. I have an F9 key to apply a contrast enhancement adjustment curve
  • Do name your layers sensibly. You may save yourself a world of hurt.
  • Do NOT crop too early – save this step for last.
  • When combining dark and light subjects (e.g. daylight-like and night) it’s usually best to have very crisp selections – not feathered selections.

Gallery of Photoshop Hot Keys

These hot-keys are described for Windows users. I use these ALL the time. Some have no menu equivalent. You can translate from Windows to Mac as follows:

Ctl -> Command
Alt -> Option
Shift -> Shift

Layer / Layer Mask shortcuts:

  • Duplicate layer dialog allows you to duplicate into another/new document!
  • Ctl-J: Duplicate the current layer
  • CtlAltShift-E   Merge visible layers to a new layer as a COPY.
  • Shiftclick on layer mask to turn it off or on.
  • Ctldrag layer mask to move it to another layer.
  • Shiftdrag a layer mask to Invert it and move it to another layer
  • Altclick a layer mask to EDIT it.
  • Altdrag a layer mask to copy it. Toss in Shift to invert the mask.
  • Shiftclick a layer mask to turn it on/off
  • Altclick quick mask icon to create an inverse layer mask from a selection
  • Do not be afraid to duplicate and adjust a layer for the sole purpose of creating a mask!

Selection shortcuts:

  • Ctlclick on layer mask to create a selection from that layer mask.
  • Ctlclick on a channel e.g. RGB, R, G, or B to make a selection based on brightness.
  • Sometimes Select -> Modify -> Expand or Contract (by 1 pixel) helps to fine-tune a selection. Feathering seldom works well for compositing light and dark images.


Sneaky Tips
Sneaky Tips
Notes from "Sneaky Tips for Processing Day and Night Photography"