September 25, 2022

Are there higher resolution photos avaialble?

I generally reduce my photos to a maximum of 1920 pixels on the longest edge for uploading to iNat. If the photo is smaller than that then that it is probably the maximum size it can possibly be after the crop was done. That means on occasion,. for larger critters, I may be able to go back and provide a larger image upon request. In other words, if the photo is at least 1920 pixels on the longest edge (either vertical or horizontal), then I may have the ability to save it to a higher resolution for printing or publishing purposes.

This does not apply to images I post to Bugguide.net, where I currently reduce those to 1000 pixels on the longest edge. Almost all of those would be available here as well in a larger size.

Posted on September 25, 2022 14:51 by thumbwave thumbwave | 0 comments | Leave a comment

May 12, 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

Posted on May 12, 2022 17:44 by thumbwave thumbwave | 0 comments | Leave a comment

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