Merging different exposures

Tim Pindar

Member
This photo isn't particularly special, as the weather in the Lake District back in 2008 was poor, but I used it to try out a technique to get good exposure of both the land and sky.

Working in PS Elements, not Lightroom, I created 2 TIFF files via Adobe Camera RAW, one exposed for each part of the photo. I then combined them with as layers, erasing part of the top one to reveal the one underneath. I took ages over the boundary with the eraser brush at high magnification. Final adjustments were carried out in Lightroom (working on the TIFF file).

Below is the before (my original shot from 2 years ago, with the land rather dark and the sky blown out) and the after.

To be honest, the boundary doesn't stand up to close scrutiny at high magnitude, but at this size it seems to be OK. However I think on the right the purple-ish hill now looks too light compared with what is behind it. I suspect that for this particular shot I'd need 3 or 4 different exposures to make it work properly.

What do you think?

And, is there a better way to do this, doing more in Lightroom and less in Photoshop?

IMG_1141-2.jpg


p932921049-4.jpg
 
I have always used photomatix for this sort of thing, now I use Topaz Adjust although it tends to be a little rubbish with clouds, see 'The Wall' and the sky in that. I think I used Topaz on the London Window Cleaner HQ too, in fact theres no doubt I did. I am however no expert when it comes to this.

I like the effect though here it's very natural looking.
 
Some versions of Photoshop have a HDR option so you can combine multiple shots of different exposures relatively automatically. Combining shots when you vave a complicated boundry is a chest pain especially if its a tree line.
 
Hmm, thanks, maybe I need to trial Photomatix or Topaz Adjust. Looking at their websites, the examples are mostly heavy HDR effects, which personally never do it for me. I'd be looking for a much more subtle effect.

Having said that, the October edition of Digital SLR Photography mag features an HDR workflow using Photomatix which produces a fairly natural effect.
 
Wow - dramatic improvement in the pic

I've done similar manual efforts at HDR - but I'm thinking there's some automated stuff available that makes this easier to play with?
 
In this case, I would have done exactly the same thing, but using the full Photoshop instead. Layers and layer masks make for easy blending. This was more a case of spotty uneven light than extreme dynamic range. With ACR, each area of the image can be optimized and then easily blended together once open in Photoshop. I really don't know the power of Elements - my newest version is many years old.

The same sort of technique can be used in photographs shot in mixed lighting conditions, with each area of the photograph balanced for the dominant light source. While it does require practice, it is not too difficult to master, fun to do and the results are great.

It will even work in place of HDR - sometimes better - and was a technique I used for years before HDR became available. This is a heavily illustrated tutorial I did back in those days. It is still useful now and really yields more realistic results than HDR in many cases.

http://www.larry-bolch.com/layers.htm

This is an introductory tutorial on layers and layer masks, aimed at beginners.
http://www.larry-bolch.com/mask-intro/
 
The last tutorial happened to be what I was trying to work out how to do last night! I was having trouble finding a way to select parts of an image based on how "bright" they were and then blend them into a darker photo. Needless to say it was a dismal failure so I will give this a try tonight.

My question is does it give better results or not than when using the exposure, recovery tools?
 
Wow - dramatic improvement in the pic

I've done similar manual efforts at HDR - but I'm thinking there's some automated stuff available that makes this easier to play with?

Yes, that's what Topaz Adjust and Photomatix seem to be? I will probably trial one, to check out whether I can get the kind of "natural" enhancement I was trying for here, as well as HDR-type images.
 
Another way I have found when the sky is bright and ground is dark, is to go to the HSL tab in Adobe Camera RAW and reduce the luminance in the blue channel considerably, and then bring up the brightness slider. It works much like a gamma control, boosting the curve in the mid-tones but leaving the black and the white end pretty much intact. Other than the sky, there is often nothing in a landscape that is blue. If the sky is reflected in water, both problems are dealt with simultaneously.

It is also possible to process sky and ground separately, which works great when the sky is MUCH brighter than the ground. Open an instance with the sky processed to taste. Reopen the image in ACR and use either the exposure or brightness slider to bring the ground up to ideal dynamic range. If the sky blows out completely, even better. When open in Photoshop, past this layer over the sky layer. Use either the Magic Wand or Select->Colour Range to select the sky. Invert the selection and click on the little rectangle with the circle on the layer palette and it will automatically generate a layer mask, which can then be edited if needed.

auto-mask.png


To edit, use the brush tool. Black is transparent and white is opaque. Using the brush with black selected will reveal the layer below. If you over-paint, switch to white to correct. Very simple. More at
http://www.larry-bolch.com/mask-intro/

The same thing can be done with a sky to simulate the effect of a Polaroid filter, and often with better results. The point of maximum polarization of light in the sky-dome is 90° to the sun. If the filter is on a wide-angle lens, the effect can be highly unnatural, with a gradient around dark-spot in the sky. The luminance slider can be used along with the saturation slider when the sky is hazy and the blue is pale.
 
I've read Larry's tutorials, which are very useful - thanks. The introduction to layer masks needed extra steps in Elements, as Layer masks can only be used on adjustment layers, unlike full Photoshop. I found the following workaround:
http://graphicssoft.about.com/od/pselements/qt/layermasks.htm

I especially liked the one where someone's portrait is deliberately blurred, but the eyes and lips are left sharp. I tried this myself, it's very effective to give a "soft focus" effect without the viewer realising that's what you've done.
 
Another way I have found when the sky is bright and ground is dark, is to go to the HSL tab in Adobe Camera RAW and reduce the luminance in the blue channel considerably, and then bring up the brightness slider. It works much like a gamma control, boosting the curve in the mid-tones but leaving the black and the white end pretty much intact. Other than the sky, there is often nothing in a landscape that is blue. If the sky is reflected in water, both problems are dealt with simultaneously.

It is also possible to process sky and ground separately, which works great when the sky is MUCH brighter than the ground. Open an instance with the sky processed to taste. Reopen the image in ACR and use either the exposure or brightness slider to bring the ground up to ideal dynamic range. If the sky blows out completely, even better. When open in Photoshop, past this layer over the sky layer. Use either the Magic Wand or Select->Colour Range to select the sky. Invert the selection and click on the little rectangle with the circle on the layer palette and it will automatically generate a layer mask, which can then be edited if needed.

auto-mask.png


To edit, use the brush tool. Black is transparent and white is opaque. Using the brush with black selected will reveal the layer below. If you over-paint, switch to white to correct. Very simple. More at
http://www.larry-bolch.com/mask-intro/

The same thing can be done with a sky to simulate the effect of a Polaroid filter, and often with better results. The point of maximum polarization of light in the sky-dome is 90° to the sun. If the filter is on a wide-angle lens, the effect can be highly unnatural, with a gradient around dark-spot in the sky. The luminance slider can be used along with the saturation slider when the sky is hazy and the blue is pale.

Thanks Larry.

The blue luminance didn't do enough in this case.

However, the Mask approach to the split exposure is a better way of doing what I did yesterday.
 
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