Archivos de diario de mayo 2022

12 de mayo de 2022

Focus Stacking Images Taken in the Field?

Can you focus stack images taken in the field? Yes, even stacking just 2 or 3 images of varying focus distances can give you an improved view of a species that can be then displayed in a single image. The key is to not make it a priority over any key iNat objectives: namely, observe but don't disturb!

Focus stacking is improving the depth of field (area of your subject that is in focus) by digitally processing multiple exposures. A simple technique using the Adobe Lightroom/Photoshop suite is as follows:

Focus stacking of multiple images: In Lightroom, process the selected images in RAW or JPG, crop and align as closely as possible. With all images selected, right-click "Edit in" and choose "Open as Layers in Photoshop...". In Photoshop, highlight all layers and from Edit menu select "Auto-Align Layers" (default "Auto" for Projection) and click "OK". from Edit menu select "Auto Blend Layers...", choose "Stack Images" (default "Seamless Tones and Colors" and "Content Aware Fill Transparent Areas" checkboxes selected). Depending on the memory and processing power of your computer, be patient. Stacks with a dozen images may take several minutes. Save where appropriate.

Now in practical terms, each image you stack should overlap in focus a little to the next image to be stacked. Secondly there can be no movement of the species under observation, or the surface that the species is resting upon. If one image has a moved leg or antenna, you might end up with the software discerning that as an extra appendage! Now you can do some editing to obscure the unwanted appendage pre or post focus-stacking... but a word of advice: an altered image is probably not a good candidate for an observation on iNat since you may inadvertently alter a key characteristic or feature of the species (in regards to season, age, sex, etc).

REF: https://flic.kr/p/2iT3c5S (2 iamges stacked)
REF: https://flic.kr/p/2iTCrY1 (4 images stacked)
REF: https://flic.kr/p/2js4aTD (9 images stacked)
REF: https://flic.kr/s/aHsmMZkFA9 (album of stacked images)

A project on iNat for observations that include focus stacked images: https://www.inaturalist.org/projects/focus-stacked-images

Ingresado el 12 de mayo de 2022 por thumbwave thumbwave | 0 comentarios | Deja un comentario

Archivos