Re: M27 and filters: It's the colors, Dumbbell!


Pete Lardizabal
 

On Aug 5, 2022, at 6:10 PM, Pete Lardizabal <p14@...> wrote:


Hi Robert!

 We can rely upon you or your wife for color discrimination over the Pantone color swatch cards?”

Some people have gifted color vision… 

Kim (my Wife) has taken the Farnsworth Munsell 100 Hue Test on multiple occasions and has scored 0 transpositions on two tests and always scored at the “Superior” rating on other tests. I test “Low” with poor resolution ability with respect to anything “green” 🤣.

Reference Standards and Calibrations are a must for commercial work but I’m a hobbyist who shares some works with others. I will check my MacBook Pro monitor for gray scale and have Kim check the “color” here and there. 

On occasion I’ll help out as a backup photographer for a local business but I’ll hand over the RAW files and let them process the files with all the calibrated monitors and certified processing pros to take care of the collected images. 

Usually my at home renderings are pretty close to theirs… but I’m just a processing neophyte who is somewhat color blind having some fun with the hobby. 

😉

Pete

On Aug 5, 2022, at 5:14 PM, ROBERT WYNNE <robert-wynne@...> wrote:


We can rely upon you or your wife for color discrimination over the Pantone color swatch cards? They used to be the standard against which inks were compounded for color printing back in the day.

Apple has done several projects as has Adobe, who vends Photoshop regarding human perception vs realty both for DPI resolution and color shift discrimination by the human eye. I was part of a study that determined human visual cognition of moving objects and their direction regarding velocity and pixel size. Thanks for the interesting post. -Best, Robert
On 08/04/2022 6:01 PM Pete Lardizabal <p14@...> wrote:



I’m someone with a color vision deficiency. Perception verses analytically objective data collection are two different considerations. 

The Courts have touched on the subject of how real or correct an image is. Generally if an image is “unaltered” (out of the camera) or an audit trail/edit log is available the image is acceptable at trial. Interesting in that how the camera is setup can shift “reality”. Then consider images of evidence captured in wavelengths we humans can’t perceive such as UV and IR. Astronomical hobbyist imagers need not worry about standing up to the muster of the Courts; however, Astronomical Researchers face peer review. 

I can perceive “green”; however, my resolution of greens is very poor… before my color vision was properly tested (when I started working in Forensic labs in 1980) I couldn’t fathom why a box of Crayola crayons had so many green choices with different names but they ALL LOOKED THE SAME! 😆

Dynamic range also comes into play. I would argue few can perceive features on the surface of our Sun without filtration and conversely how many can resolve colors in nebula?

When processing my own images (primarily terrestrial daytime) I’ll try and image a “white” card as a reference for color balance. If I didn’t have a chance to do so I’ll try and select temps based on a close fit (shade, cloudy, full sun, etc) and then season to taste. My Wife has been tested as a Superior Color Discriminator and I’ll often ask for her input with respect to color. 😉

I find the art and science of imaging so challenging and enjoyable. 

😎

Pete

On Aug 4, 2022, at 7:21 PM, ROBERT WYNNE <robert-wynne@...> wrote:

I have long wondered about post-processed images and whether they are true to the eye of the beholder. Or if it's the eye of the beholder that drives how & what the imager wants his image to appear. With Photoshop you can make any photo appear as one would want - apart from PS limitations? There doesn't seem to be something like a NIST standard for astrophotographs. It's one reason I've held back from posting the few  photos I have as I don't know if the image I've captured is what the image would realistically appear in space to the human eye. The moon and planets are straightforward but DSO is entirely another matter.-Best, Robert
On 08/04/2022 12:59 PM Howard Ritter via groups.io <howard.ritter@...> wrote:


Hi, Brian—

Thanks for the input. I was frankly surprised at how good a result I could get from an unfiltered image made in a Bortle 7 area, especially with my limited processing skills and using only Photoshop. I’d like to see what an experienced image wrangler could do with the file using their choice of software.

I’m with you on using the Hubble palette and other arbitrary color mappings. They were developed for scientific purposes, and i don’t understand the fascination with using them for images that are only made for esthetic enjoyment. I certainly don’t criticize anyone’s taste along these lines, just saying I don’t understand it. De gustibus and all that. 

The only thing everybody might agree on is that the best possible results would come from going to a Bortle 1 for a week of imaging three two or three times a year, leaving narrowband filters behind

—howard


On Aug 4, 2022, at 1:43 PM, Brian Kaine <briankaine@...> wrote:
Howard,

I like all three images, but do prefer the first unfiltered rendition of M27. The colors are
natural, and the starry background really puts the nebula into the context of space. From
an artistic standpoint, I have never cared much for false-color images; I see them as being
arbitrary and artificial. But as a former NASA research scientist, I do appreciate their great
scientific value!

And that first image brings back memories. The first serious astronomy book my parents
bought for me was "Astronomy" by Fred Hoyle; I still have it. The dust jacket is a photo
of the Dumbbell, exactly as in your image.

Thanks for posting.

Brian

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