Curious About Rainbows.
Oct 17, 2012 09:28:06 #
I tried to snap a really vivid rainbow when I was on holiday, but the compact that I had with me couldn't go wide enough to capture the whole rainbow in one go. I had to settle for snapping each end separately. I am curious to know what is the maximum focal length that can capture a rainbow in one go.
Ideally the rainbow wouldn't go edge to edge - there would be a bit of clear space all round (that's why I said "maximum focal length" above). I am assuming that rainbows always require the same angle of view (is this right?).
My compact is 28mm equiv at its widest.
Ideally the rainbow wouldn't go edge to edge - there would be a bit of clear space all round (that's why I said "maximum focal length" above). I am assuming that rainbows always require the same angle of view (is this right?).
My compact is 28mm equiv at its widest.
Oct 17, 2012 12:20:56 #
If my newly installed Google Chrome browser is working, I should be able to upload the pictures in question.
EDIT..... Success.
EDIT..... Success.
Left hand side.....
....then right hand side.
Oct 17, 2012 17:55:16 #
R.G. wrote:
If my newly installed Google Chrome browser is working, I should be able to upload the pictures in question.
EDIT..... Success.
EDIT..... Success.
I like to play... ;-)
Esther
PSE9 Panorama
Oct 17, 2012 19:09:52 #
EstherP wrote:
I like to play... ;-)
Esther
R.G. wrote:
If my newly installed Google Chrome browser is working, I should be able to upload the pictures in question.
EDIT..... Success.
EDIT..... Success.
I like to play... ;-)
Esther
Nice work!
If the OP would upload with "store original" checked you could give back a more detailed panorama.
I like to play too. Juiced up the bow with a multiply layer and then lightened a bit with a screen layer.
Also did a little repair on the road in lower left but it could be done better or cropped out.
Replaced screen layer with another multiply layer @25%
And with saturation pumped up
Oct 17, 2012 19:24:44 #
Oct 18, 2012 08:51:06 #
R.G. wrote:
I tried to snap a really vivid rainbow when I was ... (show quote)
You are right that rainbows all subtend the same angle of view. This is 42 deg vertically or 84 horizontally. See http://ffden-2.phys.uaf.edu/211.fall2000.web.projects/Vlada%20P%20Mcghee/RainbowShape.html
The lens size depends on the camera. For example, a Canon crop-sensor DSLR (600D) requires a 12 mm lens to subtend 85 deg. See http://www.howardedin.com/articles/fov.html
The way I would take the picture, if I didn't want a panorama, would be to take two or preferably three shots with the camera in portrait mode using my 17 mm lens (27 mm equivalent), then stitch them and crop to 6 * 4 ratio.
Oct 18, 2012 10:18:02 #
DaveMM wrote:
I am assuming that rainbows always require the s... (show quote)
I didn't know that.
It seems that waterfall rainbows are an exception?
What are your thoughts about using a polarizer with rainbows?
Oct 18, 2012 10:23:53 #
DaveMM wrote:
quote=R.G. I tried to snap a really vivid rainbow... (show quote)
The other thing you might try is to use a fish eye lens and then use the lens correction filter in Photoshop. I have used that technique with good results, although I have not tried it with a rainbow.
TRIVIA QUESTION: And this one will be easy for small plane pilots - if you see a rainbow from a small airplane, what shape will it be?
Oct 18, 2012 11:10:45 #
Oct 18, 2012 11:21:59 #
Pablo8
Loc: Nottingham UK.
MtnMan wrote:
quote=DaveMM I am assuming that rainbows always... (show quote)
To see a rainbow, the sun must be very much on your back. To use a polarizer filter to darken skies, the sun needs to be at 90% to the shooting angle. We only have one sun in our solar system. You will get a darkening effect from the density of the filter. But that is not the effect of polarization.
Oct 18, 2012 11:40:45 #
Pablo8 wrote:
To see a rainbow, the sun must be very much on your back. To use a polarizer filter to darken skies, the sun needs to be at 90% to the shooting angle. We only have one sun in our solar system. You will get a darkening effect from the density of the filter. But that is not the effect of polarization.
The polarizer works on light reflected from a partially reflective surface...which is polarized. So I can see where it might help accentuate the colors. I also see where it might have the opposite effect and get rid of the colors...which are both refracted and reflected by the droplets.
But I've never tried it. I didn't think it would work either but some UHH posters have claimed it does. I have new better quality polarizer so I plan to try it next time a rainbow comes along. It will be immediately evident through rotating it whether it is doing anything. It doesn't even have to be on the camera.
Have you tried it?
Oct 18, 2012 15:05:18 #
Thanks everyone - I've downloaded the stitched rainbows (You can't see the join - awesome). :thumbup:
I'd love to stay and chat, but I've got an early shift tomorrow, so it's off to bed (there's no denying I need my beauty sleep). Thanks for the info - I'll check out the links when time permits.
Note to waterbug49307:- The person that you are complementing won't know unless you name names!!
I'd love to stay and chat, but I've got an early shift tomorrow, so it's off to bed (there's no denying I need my beauty sleep). Thanks for the info - I'll check out the links when time permits.
Note to waterbug49307:- The person that you are complementing won't know unless you name names!!
Oct 18, 2012 15:07:28 #
Oct 18, 2012 15:08:31 #
Oct 18, 2012 15:49:58 #
waterbug49307 wrote:
EstherP - You do amazing work!
Thank you, but
I'll pass the credit to where it belongs: PSE9 !
I've been using PSE since version 9 (and right now am trying to give my son the idea I would like version 11 for Christmas)
To join these two images was as simple as saving them to my hd, opening both in PSE, then selecting New -> Panorama -> open images, click OK, watch the 'puter go through its paces, and there it was.
I've had a lot of fun with panoramas, use them a fair bit in my scrapbooking.
EstherP
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