Capture: Two Tone
424 Responses
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Hebe, in reply to
Your Rangitoto is amazing: theatrical and sacrificial. Love it.
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JacksonP, in reply to
I really should look into printing it
Yep, I'd have that on my wall. Shots Bruce.
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Nora Leggs, in reply to
Rangitoto from a gun emplacement on North Head
Brilliant - total admiration for the idea and the painstaking execution! The icy cold pictures are beautiful too - they really look cold.
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I will also post my admiration of the Rangitoto.
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I went hunting for some spectral response info for films and stumbled upon a couple that make interesting reading and hopefully explain things. “Panchromatic” is the term i was looking for. Early film was only sensitive to the blue end of the spectrum. Eventually they progressed into the greens and a wee bit into the red. The reason you can use a red light in the darkroom was the film was not sensitive to red light!!!
This first page has a bit of the stuff I was playing with years ago in the aerial survey work. Now done with satellites a whole lot more with more and more and narrower bands to filter the spectrum into channels. The graph on different spectral response to grass, ground, trees, sea etc shows why colours are what they are. Note the extreme high reflectance in the near infrared of green and growing plants. This was/is useful to pick the health of grass or crops because the near infrared reflectance drops when the crop becomes stressed.
http://www.geog.ucsb.edu/~jeff/115a/lectures/films_and_filters.html
This Agfa page gives some specs on B&W aerial film to demonstrate the different spectral response and their uses.
This guy is trying to emulate Ansell Adams which I think someone here was too.
http://www.johndavies.uk.com/atec.htm
B&W film is nice to use with filters because there is only one layer to get exposed. With colour film and digital cameras the problem is the different layers spill over into adjacent colours. So even though a green filter on a digital camera only lets in green light, because the blue and the red has some sensitivity to green, they too get exposed. As someone alluded to, splitting the image into RGB and eliminating it from the product AND using a filter is useful.
The upshot is, if you want to have a real RGB image with a digital camera then you have to take 3 pictures of the same scene. Use a blue filter and delete the green and red layer, then use a green filter and eliminate the blue and red, then a red filter and eliminate the blue and green. Combining what remains should be a true RGB image. The filters MUST be good cutoffs and let minimal light through outside their band.
Polarising filters a cool for enhancing contrast in sky scenes. The blue light from the sky can be highly polarised in different directions around the sky.
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Ian Dalziel, in reply to
Album-men...
Rangitoto from a gun emplacement on North Head.
Praymate of the Month Gatefold?:
The Volcaniclastic Bolthengehole Alignment! -
Ian Dalziel, in reply to
Building sight
Building site
Setting the tone...
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JacksonP, in reply to
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Lilith __, in reply to
The reason you can use a red light in the darkroom was the film was not sensitive to red light!!!
In fact, you can't even use a safelight dealing with undeveloped film - you have to thread it on to the spool for developing in complete darkness. And although b & w paper isn't very sensitive to red light, if you leave unexposed paper out for an hour under safelight, it will darken.
All part of the excitement of darkroom ritual!
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Thinking about it, messing with luminance in HSL (as you apparently can in Photoshop's raw editor) is probably most like a filter (though still not very like). At least, most-like aside from just cutting out one or two RGB channels.
https://www.video2brain.com/en/lessons/hsl-adjustmentsWhich isn't to say there's anything wrong with curves, I was just thinking the effect would reach across the spectrum (for desaturated colours) in a way a filter wouldn't.
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Disclaimer: I was going to say the above was based on the rather wrong assumption that all the colours coming into the camera are due to the corresponding wavelength of light.
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Lilith __, in reply to
HSL is a great tool. Because digital images tend to go completely blank in the highlights, I habitually underexpose and then tweak up the shadow areas (in which there is often a surprising amount of information) and then adjust colour and contrast to give a balanced image.
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I also habitually underexpose because detail is better recorded in dark areas than bright on my camera.
HSL conversions on computer basically work by plugging each of the sensor values into a formula. The controversial part is the L, where there are different ways of calculating lightness just like there are different conversions to greyscale. A lot of L conversions (and greyscale ones) heavily favour the green sensor information as humans are most sensitive to that part of the spectrum (so are 60% to 70% green with most of the rest being the red). -
Nora Leggs, in reply to
Thanks Lilith and David - I'm beginning to see I probably don't need that Leica M. But I'm also seeing a lot of learning and pfaffing around on the computer in my future - at least it's cleaner than the darkroom!
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Jos, in reply to
And soooo much more control! I love it, it's part of the pleasure of photography for me now, I look forward to playing with the images. :)
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Sacha, in reply to
that Leica M
came up in conversation today, would you believe..
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Sacha, in reply to
you have to thread it on to the spool for developing in complete darkness.
makes better lovers
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Sacha, in reply to
the excitement of darkroom ritual!
ooh yes
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Sacha, in reply to
Rangitoto from a gun emplacement on North Head.
I'd buy that
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Something I’ve found B&W is awesome for is when the weather is rubbish and colour just isn’t going to be a factor. Plus, when I stack my cheap ND and ND grad filters I get horrible colour casts which are a trial to get rid of in post processing.
But make it B&W and most of that kind of goes away, from original colour cast heavy shot to B&W.
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