Monday, January 11, 2021

Welcome to 2021

Last year I decided to 'withdraw' all my ML-Lua legacy scripts and start afresh, as many of the scripts had evolved over a period and changed considerably, as my ideas matured.

The first script I looked at was the ML script for providing focus infomation, ie for taking focus bracket sets, exposure bracket sets and pano bracket sets etc.

The resultant script was called Depth Of Field Information Script (DOFIS) which, IMHO, provides the ML shooter the best tool for setting focus, ie:

  • Knowing the lens principal planes and the exit and entrance pupil positions;
  • Knowing the infinity blur at any focus position;
  • Setting infinity by knowing the blur;
  • Estimating the position of the pano pivot point, relative to the sensor;
  • Providing feedback when undertaking landscape focus bracketing;
  • Carrying out exposure bracketing, with or without focus bracketing;
  • Providing additional information to support the user, eg focus breathing impact on FoV.

Today I'm releasing the next refreshed script. This one aimed at supporting the shooter who is looking to create bracket sets to reduce noise and/or create super resolution images.

I'm calling the script the MUlti Shot Image Capture (MUSIC) script, and it is downloadable from the right hand 'My Scripts' area.

I'm not going to waste time discussing noise reduction and super resolution bracketing, as others have covered this, eg:

MUSIC is a very simple script and arguably isn't required, however, I decided to write it as it has a few features that support the user, that are not found elsewhere, eg:

  • Dark frame bookends
  • Tripod-based focus jiggling
  • Focus step measuring

Dark frame bookends is something I find to be essential if I'm capturing many bracket sets, as the bookends help differentiate the various bracket sets in post.

Focus jiggling is a non proven way to do super resolution and based on the 'assumption' that moving the lens focus between images may (sic) create small image to image movements at the sensor pixel level, eg a few microns, because of lens element tolerances and movements. As I say, this remains unproven. However, if you can't carry out 'normal', handheld super resolution bracketing, eg because of shutter speed, then focus jiggling may introduction enough image to image jitter to allow you to carry your super resolution processing. If it doesn't, at least you will be able to reduce the noise in your image, ie by sq.root(n); where n is the number of images taken.

The focus measurement feature in MUSIC allows you to measure the number of small focus steps between your current focus and infinity. This is simply a bonus feature, not related to NR or SR image capture.

MUSIC's menu looks like this:

I believe the menu is self explanatory, but note:

  • The number of images is limited to between 4 and 64 (but you can change this in the script)
  • The delay is limited to between 0 and 5 seconds (once again change in the script if you wish)
  • Focus mode has two options: At this focus and, if AF enabled, move to the hyperfocal before capturing the NR/SR brackets
  • Focus shift mode allows you to focus jiggle in a specific direction, eg towards or away from infinity. This is useful if you are focused at the lens extremes

To run the script simply press SET with 'Run Script' selected. If 'Measure?' is selected the script will provide on screen feedback of the number of (small) steps between the current focus and infinity.

As for post processing: as others have written about this, I won't go into detail here, other than a few words on how I do super resolution processing:

  • Having ingested the images into LR or PS, I tweak the basic RAW settings, eg highlights and shadows;
  • I stack all the images into one document;
  • If undertaking super resolution processing, I upscale the document by, say, 200%, using nearest neighbour;
  • I auto align the images;
  • I create a smart object and use the median statistic to create a single image stack;
  • I flatten the image and either leave as is or reduce in size by 50%.
Bottom line: I intend to slowly refresh/republish my legacy scripts. Hopefully MUSIC will help those looking to capture NR or SR bracket sets. As usual I welcome any feedback on this post.

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