Can anyone please advice me on how to get this kind of look in Photoshop? Those kind of bluish/turquoise tones:
One way to get a blue background is to put an orange coloured gel on your lights.
You also want to make sure your subject is mainly lit by the flash, and the background is lit by ambient light. With that set-up the only post-processing you need to do to get the blue effect is adjusting the white balance for that gel, so make sure you're shooting in RAW. The colour of gel you need will depend on the ambient lighting.
You could of course simulate the same thing in Photoshop. Set up two layers containing the same image, but with with different white balance settings. From there create a mask on the top layer to control which parts of the image use which white balance setting.
There are two aspects to this question:
These images have a very narrow depth of field - the subject is in focus and everything else is very soft.
This is purely the result of using a very wide aperture, available only on a prime lens at its widest aperture, and probably a full frame or larger sensor.
Zoom lenses won't go wide enough in aperture for this. Crop sensors will reduce the effect a bit. You should experiment with a prime lens, anywhere from say 50mm to 135mm equivalent (so-called "portrait" lenses fall within the 105-135mm range and have relatively wide apertures).
Lighting and colours
All lighting sources for these images, including the outdoor ones, are diffuse - that is, there are no direct light sources and therefore no hard-edged shadows.
In this case, the biggest contributing factor is that this was an overcast day, so there is no direct sunlight. When shooting in the studio, you can control this with bouncing flash off walls, using umbrellas and softboxes, etc but at a wedding you usually don't have this level of control - if there is direct sunlight you could potentially direct people to stay in the shade or block the sun with a screen. Indoors, if you are practically unable to use a full lighting setup, you might direct people to where the natural light looks more pleasant and maybe even use reflectors.
As for the colours, this is largely going to be photoshop-work (or equivalent). These colours are somewhat desaturated, but probably selectively (ie, some colours/areas of the image desaturated more than others) with some amount of gradient mapping applied, though also to some areas of the image more than others. Do experiment with gradient mapping as you can get a feel for how you might be able to manipulate colours a bit like this.
My approach would be playing with:
Lower the saturation.
The curves or levels (to overexpose). If you use the levels use the gamma slider (midtones).
I see some additional steps there like masking the bride, working some tones there, and applying the blue to the rest of the background.
Remember to work new effects in new layers. You can vary the opacity to achieve different amounts of the tints.
In general terms I would explore from there.
These Kind of effect can be achieved through the individual control over colors on a particular image. Light room is very good at dealing with these kind of effects as it has specific tools to gives us the utter control over colors. Shadow highlight, HSL/Saturation/Luminance control options can be used to alter the color or color combinations. There are many presets can be downloaded.
In a copy of the original image, convert to grayscale mode and then to duotone mode. Select black and blue colors for the two tones. You can decrease the contribution of the blue tone using its curve (click and drag the curve down and to the right).
Soften the entire image with a blur filter, or just parts of it with the blur tool.
Convert the image back to RGB Color mode.
Add the original image back in as a new top layer. Mask any objects in that layer that you want to appear in their original color in the final image.