Measuring the Blueness of the Sky

 

The Cyanometer, an instrument invented in 1789 by Horace-Bénédict de Saussure and used by the famous explorer Alexander von Humboldt to measure the blueness of the sky. Originally a scientific tool used to study the atmospheric moisture and particle content, a darker blue reading indicated less water vapour, while a lighter, whiter blue suggested more moisture or pollution.  The original design consisted of 52 or 53 shades of Prussian Blue on a circular card. Contemporary interpretations of the cyanometer have appealed to artists, particularly as a guide for accurately mixing sky colours in paintings. They range from DIY YouTube tutorial videos using watercolours to studies of the optimal combination of modern pigments needed to simulate the sky's full chromatic range.

This video was prepared by an AI, Google’s Notebook LM, to summarise some key sources that collectively establish the cyanometer's historical significance, its scientific function, and its continued relevance as an artistic and educational tool for studying colour and the environment.

Reluctantly replacing the sky

I'm definitely not a sky replacement guy, but there has been so much discussion and hype about it I figured I should at least try it. This is a photo I was looking to capture the "sparkle" on the lake with a low winter sun backlighting the scene. This is a challenging photo from the rigors of exposure given the Dynamic Range to be captured, Getting detail in the foreground shadows means the sky (which was the vivid Australian sky blue becomes a blown out grey/blue. Importantly I hadn't taken a bracketed set., to no real chance to recover the sky

Original Photo

My recent purchase (Update?) to Luminar Neo. With it big promotion of the ease of Sky Replacement meant I really should try it out, despite my reluctance to do such things. So here are three results, all achieve with one click to select a sky from Luminar Neo's library and a couple of tweaks for Sky Orientation (the positioning of the sun) and also the Scene Relighting.

Adding a blue sky (clouds)  & relighting

Making it Overcast

Moving to the Golden Hour?

Does it worry me that they all look uncannily real?

Yes a little.

A wonderful end to the day

A Photo Worth Taking

Sometimes there will be beautiful light and you don't have you camera, but you will have your phone. This was taken with my new HTC Uplay smartphone and its basic camera app in panorama mode. I’m certainly rethinking the need to carry a second camera body in my travels.

PhotoFriday :: Tall

 

For PhotoFriday‘s topic Tall

PhotoFriday :: Park

Threatening Rain

For PhotoFriday‘s topic Park

Blue Skies

I was taking some clouds when a jet flew over leaving a long contrails ( or chemtrails if your a  conspiracy theorist) or maybe it was dumping fuel, but it did leave a fascinating bright streak across a bright blue sky.

Interesting Cloud Formation

Just before sunset this interesting cloud formation was lit by the setting sun. another of those fleeting moments.

Winter Skies

Winter weather has arrived

PhotoFriday :: Big Sky Panorama

Another Big Sky Multi-image Stitched panorama, finished with “hand painted” (using Corel photo paint) edges. This series was taken about 5 minutes before the dark skies over the lake series.

For PhotoFriday‘s topic Sky

One Day, Two Sunsets

If you travel west towards east for long enough, and at the right times you can have the weird experience (not to mention jet lag) of seeing two sunset about 16 to 17 hours  apart. Flying from Jeddah to Melbourne via Abu Dhabi I managed to photograph two sunsets in the same day (well as measured by my camera). I slept though the sunrise.

Approaching Abu Dhabi

Arriving at Melbourne

Photofriday :: Morning has Broken–Revisited

For PhotoFriday‘s topic Early Morning

 

When I took this shot last week I( was actually pleased with it tonal but not colour and the original is posted on flickr. BUT it was quiet a magical moment to be there, the sun was breaking through the low morning cloud and exposing some promising blue sky above, and the dust and sand haze was still hugging the grown and the shafts of light where casting a gold glow. So I set about reprocessing the image on two parts (layers) in Perfect Effect 8 to cool the sky and warm the shafts of light in the dust and every so carefully  applying a clarity tone adjusted to the whole. Its now much closer to what I remember, well in my minds eye.

Silky Oaks Golden Crown

  The outburst of yellow florets on the silky oak seem earlier this year and perhaps fuller than usual. Normally the golden flush is in the week leading up to Christmas.

PhotoFriday :: Fiery Sky

For PhotoFriday‘s topic Fiery

Waiting for the Aurora

Milky Way Panorama 1, originally uploaded by imageo.

The K-index has been 3 and over for the past few days which signals there is a possibility that the Aurora Australia will be visible from the southern coast of Victoria. Well it rained a lot but between breaks I got good views of the milky way arcing across the sky. Both these images are prepared from a sets of photos and stitched with Autostitch.

milky Way Panorama 2, originally uploaded by imageo.

Winter is coming, and the lighting can be dramatic

Winter is approaching and the skies are getting much more animated, In particular the glimpse of strong sunlight between dark clouds so often bringing the landscape alive. Its a good time of year to always have your camera with you and not be afraid to stop and take in the wonderful lighting effects and get a few “special” shots. Both of these shots, where taken by the side of the road when I noticed a fleeting moment of great lighting. Both where shot without filters but I did use the Adjustment brush in lightroom to lift the highlights a little. The Panorama below was created with autostitch using 8 “portrait” orientated overlapping photos.

Dark Skys

Autostiched panorama created from 6 photos.

Towards Blue(r) Sky(s)

Original (Polarizing)	Increased Saturation	Decrease Luminance
The light in summer here in Australia is very intense and it is really hard to get a decent blue sky. So I normally have a polaroid filter screwed on the front of my camera from November to April. The filter works a lot like the sun glasses, at different angles they will filter out and cut the intensity of the light. By rotating the filter you can see the darkening. As well as helping darkening the blue of the sky versus gulls or clouds, the polaroid can also work like a mini neutral density filter, to give you a slightly longer exposure on some landscapes.	The common approach is just make the sky bluer by increasing the colours saturation. In Lightroom you’d go to the develop module and slide the saturation slider to the right. Notice the gulls beak is also a more intense yellow	This is a less obvious route, In Lightroom you can go down to colour adjustment and in the HSL tab go into the Luminace panel and hold back on the blue a little. This just darkens the blue only and leaves the tonal range and colours on the gull untouched.

Head in the clouds

Catch a Falling Star

Last night was a new moon and relative still. Good conditions to capture the night sky. So with a little experimentation in M for Manual on my canon, I opened it up (f4.5), set the ISO High (6400) and the exposure long (30 seconds), all on a tripod of coarse. There was a bit of cloud about but they just added to the mood. Distant car head lights on a nearby tree added to that ambience With such a high ISO and long exposure the resulting photos where littered with “digital” noise and Lightrooms RAW processor handles this well even with the luminance and colour noise sliders moved way to the right.
I did see a couple of brief shooting stars but my camera was not exposing at the time or pointed elsewhere, such is life. However as I looked in detail in Lightroom I did pick up some distinct streak which I am now fairly certain must have also been meteorites. I have seen other streak in long exposure that where a series of aligned dots, I assume these are aeroplane lights or satellite. The shooting stars/ meteorites giving a a continuous light.