This seems very handy – however the reference image would be infinitely easier to print on the correct size if it was a PDF file. PNG image format does not retain the resolution IIRC.
With a PDF file you can also make the image crop box be exactly the reference image area, add crop marks and put the CC note and other info possibly inside or outside the crop area.
Its all very well saying "here's a free photographic reference, download it and print it". But I worry about the lousy job your average cheap home inkjet printer will do of getting it onto paper.
Some things are just better bought from a reputable manufacturer than bodging your own. Photographic reference charts may well be one of them.
I've been using this for my photo adventures; I try to keep it in my wallet at all times (I worry about it getting discolored by rubbing against other cards though) and whenever I notice that the white balance is gonna get fucky (esp when there are multiple light sources) I whip that out and take a picture of it in the same scene.
edit: Also people love to use grey cards for getting exposure right but it's complete bunk science; if you're using the raw workflow (if you're fine tuning white balance you almost definitely are) you should shoot as bright as practically possible and not too bright to prevent clipping and adjust exposure as you see fit in editing.
Unless you are doing extreme precision professional work--likely an extremely small subset of the people reading this, if any--a calibration target from a black and white laser printer or a photo printer is fine and will give great results.
Some photographers seem to worship color correction in a weird way. Other error factors, like reflected light hitting your calibration target, are likely to supercede any minor color imprecision from those kinds of printers.
Wouldn't practically all printers do middle grey with only black ink/toner/whatever, thus having very little chance of having any color cast? Considering how color temp adjustment is not very exact thing to start with, I feel that generic printout should be good enough for most uses. And for color critical work, you'll want a full color swatch (eg colorchecker) anyways instead of just middle grey.
Thanks for posting the link, because I was about to ask. It seems like printing out the reference on a home printer would make the accuracy dependent on whether or not your printer was well calibrated (and then you're back to the same problem about color accuracy.)
I was scanning satellite photos yesterday and came across what I think are ground reference points built to enable determination of exact ground distances using a series of concentric rings and oriented linear features. I believe knowledge of the exact diameter of the rings and length of the chords would allow a user to measure features in the photo with acceptable precision.
I know that early pilots had a series of markers that they could use to keep themselves on track as they flew their long distance routes. These things were oriented concrete markers, some of which are still accessible.
We all need a reference, a way to cross-check or ground truth our results and conclusions.
I'm curious if there are any good methods for correcting lens distortion. Like can I print a poster, take a photo and use that to create a correction map?
The theory behind modern light metering is that if you average the "brightness" of every pixel (or the average density of crystals in the case of film) is should "visually" be around 50% brightness or density, or neutral grey. Spot metering on something that's already neutral gray sort of short cuts that process
[+] [-] peterhil|4 years ago|reply
[+] [-] peterhil|4 years ago|reply
[+] [-] peterhil|4 years ago|reply
[+] [-] traceroute66|4 years ago|reply
Some things are just better bought from a reputable manufacturer than bodging your own. Photographic reference charts may well be one of them.
[+] [-] hatsunearu|4 years ago|reply
https://smile.amazon.com/WhiBal-White-Balance-Pocket-Card/dp...
I've been using this for my photo adventures; I try to keep it in my wallet at all times (I worry about it getting discolored by rubbing against other cards though) and whenever I notice that the white balance is gonna get fucky (esp when there are multiple light sources) I whip that out and take a picture of it in the same scene.
edit: Also people love to use grey cards for getting exposure right but it's complete bunk science; if you're using the raw workflow (if you're fine tuning white balance you almost definitely are) you should shoot as bright as practically possible and not too bright to prevent clipping and adjust exposure as you see fit in editing.
[+] [-] D13Fd|4 years ago|reply
Some photographers seem to worship color correction in a weird way. Other error factors, like reflected light hitting your calibration target, are likely to supercede any minor color imprecision from those kinds of printers.
[+] [-] zokier|4 years ago|reply
[+] [-] smodad|4 years ago|reply
[+] [-] doodlebugging|4 years ago|reply
I know that early pilots had a series of markers that they could use to keep themselves on track as they flew their long distance routes. These things were oriented concrete markers, some of which are still accessible.
We all need a reference, a way to cross-check or ground truth our results and conclusions.
[+] [-] dcminter|4 years ago|reply
Though I note that that one looks suspiciously like the contra-recommended laser printed output.
Baader-Meinhof phenomenon - or did reading that Beeb article inspire someone to find and post this one?
[+] [-] iseanstevens|4 years ago|reply
I’ve done some little experiments but having a standard-ish thing is better.
Would this integrate to give scale, in say, Meshroom? Or it’s manual calibration step someplace along the workflow?
I’m in it more for the reasonably accurate 2d/3d measurements, but approximately accurate color is nice as well.
[+] [-] snoopen|4 years ago|reply
[+] [-] yboris|4 years ago|reply
https://www.dxo.com/technology/lens-distortions/
The way it works, iirc, is you can choose the model of your lens and the software fixes things. Works for professional lenses, unsure about others.
[+] [-] zokier|4 years ago|reply
For more advanced stuff, look up CAHVORE models and related models.
[+] [-] mrichards212a|4 years ago|reply
[+] [-] neolog|4 years ago|reply
[+] [-] jedimastert|4 years ago|reply
The theory behind modern light metering is that if you average the "brightness" of every pixel (or the average density of crystals in the case of film) is should "visually" be around 50% brightness or density, or neutral grey. Spot metering on something that's already neutral gray sort of short cuts that process
[+] [-] stavros|4 years ago|reply
[+] [-] pfortuny|4 years ago|reply