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I give in...
#31
Quote:I'm not convinced that "invisible spectrum" is the cause here. That can only really be NIR or UV. On an intentionally modified camera (all filters removed other than bayer itself) the UV sensitivity was nothing much to speak of since most normal glass is pretty effective at blocking it anyway. For practical purposes the sensitivity of an unmodified camera is zero. NIR sensitivity is relatively higher but more complex as the typical bayer colour filters vary in their IR wavelength sensitivity, so you can get some interesting false colour images from that. But a standard camera will have a pretty effective IR block filter separate to that. Relative to a scene with visible light, the sensitivity is so low down to be insignificant.

 

Most likely if you're struggling with deep blues/purples in images, then after making sure you're not channel clipping, it is more a colour management in workflow problem.
No, it is an "IR" and/or UV problem (flowers do have those colours to attract insects). How can one tell, easily? As it is only with flowers that this problem occurs. Put the same colour (according to your eyes) next to the flower, but of man made material, and you see the difference. So, not a colour management problem.

 

By the way, older digital cameras struggled much more than the ones I have now.
#32
That is the wrong test. Our eyes are useless at determining spectrum which is what matters here. The best test would be to take the same photo with and without a known effective UV/IR block filter. My argument is that you wouldn't see a difference, whereas if you are right, you would.

 

Alternatively you could try using a "clean" light source so there is no UV or IR to detect. Apart from direct sunlight, I don't think there are any significant sources of UV in normal lighting. So using artificial lighting for example as a substitute may eliminate that, but there may still be an IR component depending on the light source. Ever tried IR photography? For practical purposes, of lighting you're likely to encounter in a domestic environment, only incandescent bulbs really put out much photographic IR. Fluorescent and LEDs are pretty clean there.

<a class="bbc_url" href="http://snowporing.deviantart.com/">dA</a> Canon 7D2, 7D, 5D2, 600D, 450D, 300D IR modified, 1D, EF-S 10-18, 15-85, EF 35/2, 85/1.8, 135/2, 70-300L, 100-400L, MP-E65, Zeiss 2/50, Sigma 150 macro, 120-300/2.8, Samyang 8mm fisheye, Olympus E-P1, Panasonic 20/1.7, Sony HX9V, Fuji X100.
#33
Quote:No, it is an "IR" and/or UV problem (flowers do have those colours to attract insects). How can one tell, easily? As it is only with flowers that this problem occurs. Put the same colour (according to your eyes) next to the flower, but of man made material, and you see the difference. So, not a colour management problem.

 

By the way, older digital cameras struggled much more than the ones I have now.
This is in my view "not a just mother nature" caused problem, Ferrari's solid block red paint has no intentional UV/IR insect attracting properties that I am aware of, but when you stick the pointer on a nice expensive sunlit 400 series Ferrari, the red band figure still rockets up to 255 and then some!

 My "flower" example was simply because I want to resolve the detail in the red petals, whereas I'm not really too fussed about the molecular structure of  Ferrari's paintwork!  Smile   Rolleyes

#34
Quote:This is in my view "not a just mother nature" caused problem, Ferrari's solid block red paint has no intentional UV/IR insect attracting properties that I am aware of, but when you stick the pointer on a nice expensive sunlit 400 series Ferrari, the red band figure still rockets up to 255 and then some!

 My "flower" example was simply because I want to resolve the detail in the red petals, whereas I'm not really too fussed about the molecular structure of  Ferrari's paintwork!  Smile   Rolleyes
I have never, ever, had the same issue with red cars. They dod not pose such a problem as certain red flowers (mainly roses) and certain blue/violet/purple flowers. It is nice that the IR/UV gets dismissed by Popo, but it is a real "issue" with flowers.
#35
Quote:That is the wrong test. Our eyes are useless at determining spectrum which is what matters here. The best test would be to take the same photo with and without a known effective UV/IR block filter. My argument is that you wouldn't see a difference, whereas if you are right, you would.

 

Alternatively you could try using a "clean" light source so there is no UV or IR to detect. Apart from direct sunlight, I don't think there are any significant sources of UV in normal lighting. So using artificial lighting for example as a substitute may eliminate that, but there may still be an IR component depending on the light source. Ever tried IR photography? For practical purposes, of lighting you're likely to encounter in a domestic environment, only incandescent bulbs really put out much photographic IR. Fluorescent and LEDs are pretty clean there.
That makes little sense... If a red flower in the same sunlight looks the same as a red object, and one makes a photo and only the flower poses a problem, then it is an "invisible" spectrum problem. No need to use a different light source to determine that issue. Note that not all red flowers are problematic. It depends strongly on kind and variety. A red anemone or poppy are just fine to photograph, dark red velvety roses are nearly impossible.

Same with blue/violet/purple flowers. Some are easy to photograph, others even make patterns appear on photos that were not "there" when seen with the eyes.
#36
Quote:I have never, ever, had the same issue with red cars. They did not pose such a problem as certain red flowers (mainly roses) and certain blue/violet/purple flowers. It is nice that the IR/UV gets dismissed by Popo, but it is a real "issue" with flowers.
  As I've stated before I was already suffering the red problem with Pentax only turning to magenta, so when I first bought the Nikon D7100 my first tests were AF and reds in full Mediterranean summer sunshine.

 A "Harley Rally" provided a nice selection of bright red shinny bikes, arriving home I put the pointer on the red bikes and "damn", saturated reds, they looked better than Pentax's but nonetheless.

 

  That's how long it took to find the problem although I admit that I was looking out for it.

 

 

   I don't know what part of the world you live in Brightcolours? maybe that plays a role. I remember in a thread on Dpreview where I said I had to underexpose white birds by a full one stop and you sounded surprised, maybe it's our fierce midday sun here, and yes only Englishmen and mad dogs go out in it!
#37
Just because something looks the same to our eyes doesn't mean they are the same colour. It does matter, as our eyes and camera sensors will have a different response. They are supposed to match each other, but it is more complicated than that. Side note: the human eye can see near IR! You can build a cheap filter using several layers of primary red and congo blue lighting gels and see for yourself.

If you have tried intentionally photographing in IR or UV, you will know how much (or not) sensitivity there is. So I'm not saying it will never be noticeable, but in practical circumstances it will be swamped by visible light and likely be insignificant.

So for now I remain to be convinced that is a mechanism at play. I have proposed a method by which it could be tested, but do not have the time or resources to carry it out any time soon.
<a class="bbc_url" href="http://snowporing.deviantart.com/">dA</a> Canon 7D2, 7D, 5D2, 600D, 450D, 300D IR modified, 1D, EF-S 10-18, 15-85, EF 35/2, 85/1.8, 135/2, 70-300L, 100-400L, MP-E65, Zeiss 2/50, Sigma 150 macro, 120-300/2.8, Samyang 8mm fisheye, Olympus E-P1, Panasonic 20/1.7, Sony HX9V, Fuji X100.
#38
http://www.dslrbodies.com/newsviews/what...ecade.html

To revive my old thread, I never did get any "smaller" camera. My exercise with the fixed 50 the other day also kinda helped me think about how little I could get away with, both in sensor size and zoom range. Then I saw Thom Hogan's thoughts about the progress of sensor technology. Now, bigger sensors will have more potential with shallow depth of field stuff, but if that isn't needed, just how small of a sensor and fixed lens can you get away with?

I keep looking back at the RX100 IV. Over the standard zoom range, it can compete against APS-C size sensors. Considering aperture equivalence, it is faster than kit zooms, and you're going to have to shell out for at least a f/2.8-4 zoom to beat it by a fraction of a stop. The downer is still the price, but I really do think a camera like this could replace the mid range zoom for a lot of uses. The Canon G7X is similarly spec as far as the imaging chain is concerned and half the price... so maybe that needs a closer look too. And I still haven't ruled out an older RX100.
<a class="bbc_url" href="http://snowporing.deviantart.com/">dA</a> Canon 7D2, 7D, 5D2, 600D, 450D, 300D IR modified, 1D, EF-S 10-18, 15-85, EF 35/2, 85/1.8, 135/2, 70-300L, 100-400L, MP-E65, Zeiss 2/50, Sigma 150 macro, 120-300/2.8, Samyang 8mm fisheye, Olympus E-P1, Panasonic 20/1.7, Sony HX9V, Fuji X100.
#39
To revive your old thread:

 

http://www.imaging-resource.com/PRODS/ca...n-g5xA.HTM

 

Backside illuminated 20mp 2.7x crop sensor. 3x2 aspect ratio. 2.36M-dot OLED EVF. 8.8-36.8mm f1.8-2.8 lens (24-100mm equivalent). Fully articulated swivel LCD. 1080/60P video. Built in 3 stop ND filter. 5.9 FPS JPEG in burst mode. Internal flash. Battery charger and USB cable camera charging.

 

[Image: canon_g5x_f002.jpg]

#40
Are they doing the DSLR thing, where e.g. 5D is "above" 7D? So this model is above the G7X in features and price... will wait and see how big it is in practice, and what UK pricing turns out like. Really not in any hurry.

<a class="bbc_url" href="http://snowporing.deviantart.com/">dA</a> Canon 7D2, 7D, 5D2, 600D, 450D, 300D IR modified, 1D, EF-S 10-18, 15-85, EF 35/2, 85/1.8, 135/2, 70-300L, 100-400L, MP-E65, Zeiss 2/50, Sigma 150 macro, 120-300/2.8, Samyang 8mm fisheye, Olympus E-P1, Panasonic 20/1.7, Sony HX9V, Fuji X100.
  


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