Any tips for enhancing rainbows?
in [Digital Cameras]
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From: Chris Malcolm on 2 Jul 2010 00:53 Ofnuts <o.f.n.u.t.s(a)la.poste.net> wrote: > On 01/07/2010 17:41, Kevin McMurtrie wrote: >> In article<4c2c4621$0$1581$742ec2ed(a)news.sonic.net>, >> rfischer(a)sonic.net (Ray Fischer) wrote: >> >>> ray<ray(a)zianet.com> wrote: >>>> Ted Nolan<tednolan> wrote: >>> >>>>> I've noticed that whenever I take a picture of a rainbow, it looks much >>>>> less impressive than it did to my naked eye. >>>>> >>>>> For instance this one from yesterday is ok: >>>>> >>>>> http://www.tednolan.net/misc/p1120927.jpg >>>>> >>>>> but looked much better in real life. >>>>> >>>>> Any tips for punching rainbows up in GIMP? >>>>> >>>>> Ted >>>> >>>> Have you tried a polarizing filter? >>> >>> Won't work. Polarizing filters improve sky contrast when the camera >>> is aimed at roughly 90 degrees from the sun. Rainbows always happen >>> opposite the sun. >> >> A rainbow has polarization so a polarization filter does have an >> influence. Whether or not it helps depends on conditions and how much >> of the rainbow is in the photo. > A PL Filter can only remove light and so is only good against unwanted > polarized light. If the rainbow is polarized the PL can only attenuate > it, and not accentuate it. If the rainbow is polarised, and the filter's polarisation aligned with it, it will attenuate the rainbow less than it attenuates the surrounding unpolarised sky, thus comparatively boosting it. -- Chris Malcolm Warning: none of the above is indisputable fact.
From: bugbear on 2 Jul 2010 03:48 Martin Brown wrote: > On 30/06/2010 17:24, bugbear wrote: >> Ted Nolan <tednolan> wrote: >>> I've noticed that whenever I take a picture of a rainbow, it looks >>> much less >>> impressive than it did to my naked eye. >>> >>> For instance this one from yesterday is ok: >>> >>> http://www.tednolan.net/misc/p1120927.jpg >>> >>> but looked much better in real life. >>> >>> Any tips for punching rainbows up in GIMP? >> >> Alternatively, can anyone give an explanation >> of why photos of rainbows tend to be disappointing >> compared to the Mk1 human eyeball ? >> >> I've experienced this too. > > The problem is that the dynamic range of the scene is too high for a > camera to handle satisfactorily. It is one place where HDR imaging might > help if you have a bracketed set of exposures. > > Basically the human can distinguish brilliant pure red light as truly > pure red whereas the camera sees it as bright first then coloured second > (ie pastel shade). Weaknesses in the filter (true also for film) allow > enough crosstalk between the colour channels that it desaturates. > > You can demonstrate this under much more controlled conditions by > photographing the various brightly coloured LED indicators on hifi and > TVs at varying exposures. >> >> (some of the corrections in this thread >> have been pretty good, BTW) > > You can get something of the look and feel back by careful use of > histogram curves, contrast and brightness. But the eye is just so much > better at seeing bright coloured light as truly saturated colour. That's most interesting, since I like messing with HDR techniques. Thank you. BugBear (waiting for a rainbow)
From: John Navas on 2 Jul 2010 11:00 On Thu, 1 Jul 2010 21:06:15 -0400, in <4c2d3b96$0$5507$8f2e0ebb(a)news.shared-secrets.com>, "Peter" <peternew(a)nospamoptonline.net> wrote: >"Mike Russell" <groupsRE(a)MOVEcurvemeister.com> wrote in message >news:jy29zz20vjpb.dlg(a)mike.curvemeister.com... >> Digital math will get the job done. Use a tripod. Take two images, one >> with the rainbow attenuated, and subtract the images to emphasize the >> rainbow. > >While you are technically right this is not always possible. The life of a >rainbow is not very long. There may not be time for the tripod. >I would first get what I can get handheld, then go to your technique. >I have found a similar issue with a 'Hudson River School" shot. The special >lighting conditions lasts only a few minutes after the rain stops. If I >start to futz I may very well lose the shot altogether. Auto-bracketing and decent shutter speed can often get such images if the camera has such capabilities, and good software can easily make up for misregistration of the images. -- Best regards, John Buying a dSLR doesn't make you a photographer, it makes you a dSLR owner. "The single most important component of a camera is the twelve inches behind it." -Ansel Adams
From: nospam on 2 Jul 2010 14:06 In article <2ivr26lfoavng93f0am6cdoa5q73i6goqv(a)4ax.com>, John Navas <jncl1(a)navasgroup.com> wrote: > Auto-bracketing and decent shutter speed can often get such images if > the camera has such capabilities, and good software can easily make up > for misregistration of the images. it's not a bug, it's a feature. why do you make excuses for equipment that is not well suited for a given scenario?
From: Ray Fischer on 3 Jul 2010 17:47
Kevin McMurtrie <mcmurtrie(a)pixelmemory.us> wrote: > rfischer(a)sonic.net (Ray Fischer) wrote: >> ray <ray(a)zianet.com> wrote: >> > Ted Nolan <tednolan> wrote: >> >> Any tips for punching rainbows up in GIMP? >> >> >> > >> >Have you tried a polarizing filter? >> >> Won't work. Polarizing filters improve sky contrast when the camera >> is aimed at roughly 90 degrees from the sun. Rainbows always happen >> opposite the sun. > >A rainbow has polarization so a polarization filter does have an >influence. The orientation of the polarization is tangential to the arch of the rainbow. Unless you're shooting just a small part of the rainbow a polarizing filter is not going to do anything very useful. -- Ray Fischer rfischer(a)sonic.net |