Tue Jun 14 13:48:28 EDT 2011 John Francis wrote:
> On Tue, Jun 14, 2011 at 11:03:41AM -0400, Igor Roshchin wrote: > > > > Hi All! > > > > After taking photos at a party, I discovered an interesting effect. > > It was indoors, with uneven and not very bright light, so, I used > > a flash bounced from the ceiling, which made the light rather uniform. > > [ . . . ] > > I suspect, that this particular color (dye) fluoresces from the flush, > > or something like that. > > Quite likely - dyes (or pigments) used to colour plastic items often > have significant response to ultra-violet light. Even if they don't > fluoresce, the output from a flash can produce quite a bit of UV light, > and sensors "see" further into the UV than does the human eye. > > You could try using a UV filter on either the camera or the flash. John, Even though purple might have an mixture of blue/violet with red, I would expect that purple would be farther on the spectrum and closer to the violet part than blue. That would mean that hitting the violet (or UV) part of the spectrum should shift the color toward violet, not toward blue. Tue Jun 14 13:37:34 EDT 2011 Thibouille wrote: > Igor, under Lightroom develop module, TSI, tint: adjusting blue and > purple made a lot of difference and look more like the colour you > linked as reference. > I got blue +25 and purple +72. > > I dunno if this is close enough, but a lot better, at least to me. Indeed, that correction is close to the "original" color. I am sure, it is possible to recolor most of the photos. What I meant that it was not just the result of a WB setting, but rather a selective shift of a color. It is the first time I've seen such a drastic effect. The only other comparably drastic effect that I've seen would be clothes with reflective elements -- e.g. as in this snapshot: http://bard-cafe.komkon.org/PhotoIgor/East2002/images/DCP_0433.jpg . Sometimes, those can even mess up the exposure: http://bard-cafe.komkon.org/PhotoIgor/East2002/images/DCP_0432.jpg . Tue Jun 14 14:11:20 EDT 2011 David J Brooks wrote: > On Tue, Jun 14, 2011 at 11:03 AM, Igor Roshchin <str at komkon.org> > wrote: > > > > Hi All! > > > > After taking photos at a party, I discovered an interesting effect. > > It was indoors, with uneven and not very bright light, so, I used > > a flash bounced from the ceiling, which made the light rather uniform. > > > > There were some party items in two colors: green and purple. > > In all shots, the purple came out as blue. All other colors are > > close to the original. > > I tried to play with the color temperature and tint in LR, but I > > cannot > > make it without skewing the rest of the colors. > > I am seeing the purple as blue on my iMac. > > I have run into this problem with my D200 and SB800 flashes which as > far as i';m concerned, produce a better flash shot than my K10-D and > AF 360. > > Dave > > Dave > Double exposure? ;-) There is a pizza chain in TX called "Double Dave's" doubledaves.com . :-) I am mostly happy how Metz 58 works with my K7. Very often, especially when bouncing light from the ceiling/walls, I set the flash to "A" setting, and it exposes better than when set to P-TTL. Igor -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
