]It's a great shot - very nice subject matter to say the least :-) and nicely composed !
That blue 'tint' is actually a color cast, which dilutes the color accuracy of the entire image.
Color Casts are Killers ... they will pervade your image and reduce color accuracy.
Eyeballin' the color correction doesn't give consistant results.
But 'going by the numbers' does
Each of the 16 million or so colors in an RGB image has it's own unique numerical identity depending on the value/amount of each of the Red, Blue, and Green primary colors.
Casts can be corrected or removed in photoshop, but it is better to first calibrate you camera's sensor [if your camera has that option] to record a more nuetral capture = less post processing time and better images overall.
A quick check to see if your sensor is producing color casts:
side note - even expensive cameras aren't individually calibrated to nuetral at the factory.
Photograph a gray card in bright open shade in a nuetral setting [no major dominant color such as a green grassy field that will produce it's own reflected color contamination]
Set the camera to AWB , manual focus and exposure ,
fill the frame with the gray card and make a capture.
Since you are shooting this test in nuetral light [which doesn't have its own color cast], and you are in AWB [which wants to make every thing equally gray] you should theoretically produce an image that has equal values of Red, Green, and Blue.
Open the image in photoshop and run the mouse over the image - observe the INFO palette as you go...
If the camera sensor is spot on The R , G , B numbers should all be of equal value.
ex: R=60, G=60, B=60. Equal values of Red Green and Blue equal Gray.
The acutal number itself isn't that important - it's the equality of the numbers.
Bur for example R=60 and G=60 but
B=85 then you have a Blue cast to the image.
If R=60 and
G=70 and B=75 then you have a slightly Bluish Green Cast to the image produced by the sensor.
Incidentally, each image that the camera captures will introduce this cast to the resulting image.
Some cameras allow you to adjust the way it records color values.
Check your instruction manual.
The object here would be to get all of the numbers equal when doing the gray calibration...thereby producing a nuetral and color accurate capture in the camera.
Trial and error but it is worth it ... your initial in camera captures will be much cleaner, color accurate and vibrant - and easier to work with.
In photoshop you can also remove or nuetralize color casts in 2 ways:
#1 Open an image and add 2 curves layers.
With one Curves layer pick up the black sampler and mouse over a very dark shadow area.
Perfect black will read R=0, G=0, B=0.
If you are reading anything other than that you have a color cast in the shadow area.
Click on the shadow area with the color sampler and it will change that to perfect black and remove the color cast in the shadows.
You can do the same with the highlights - just dont read a perfect white.
Now go to the second Curves layer pick up the white sampler and mouse over a highlight but not an area that is totally blown out to perfect white.
Perfect white will read R=255, G=255, B=255.
Click on the area and it will remove the highlight cast.
Using this method will produce much more color contrast and saturation.
The only downside to this is that sometimes it will make too much of a change.
But you can fade the curves layers to bring it back some, or add another Curves layer [do an S curve adustment]and introduce gray in to the highligts and shadows to reduce the color contrast
#2 The other method is to open the image and add a duplicate layer ...
On the duplicate layer find the shadow area with the
color sampler in the tools menu [we aren't using a Curves layer this time] ...click on it and observe the color window...the sampled color will appear in the top swatch.
This is the color cast which will be nuetralized in the next step.
Now go to Image>Adjustments>Replace Color>adust fuzziness to include only the areas you wish to correct>move the Saturation Slider to desaturate.
This will nuetralize the color cast in the shadows.
Now make another duplicate layer from this layer [not the background layer]
This time sample the highlight area and repeat the process but find an area that isn't completely blown out.
This technique will remove the color casts as well, but can produce a flatter image that needs to be upped in contrast.
Hope this helps ... in photography as in all other things ... an ounce of prevention equals a pound of cure.
Sorry for the long post
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