Mixed lighting shots

[Manfred M]

Note: These panos look a lot better when you click on them to view them.

I just wanted to share some thoughts and get some feedback on how I handled a posting that I made yesterday. Night shots are by their very nature generally a mixed lighting situation and one has to deal (or ignore) a multitude of different colour temperature light sources. The traditional way to handle mixed lighting in photography is to go crazy with gels; I certainly use gels on my flashes to compensate for this situation and do know that gelling windows is sometimes used in movie / video production. Regardless, gelling all of the lights in a nighttime shot is not realistic.

When I got at looking at the shots I had taken of the Rideau canal last night; there were two primary light sources; I could either get the snow on the right side of the image looking right at the cost of an overall warm image (which is what I did in my original posting).




The other option I looked at last night was to colour balance the snow on the far side of the canal and render the National Arts Centre more accurately, at the cost of having a very blue cast on the snow on the near side of the image:





After sleeping on it, and through the magic of layer masks, I came up with two other views that resulted in more neutral colours on both sides. I went slightly cool for the background in the first instance:




In the second instance I went for an overall warmer look.




While I certainly subscribe to the concept of "get it right in camera"; it's still amazing what one can accomplish in Photoshop.

[DanK]

Manfred,

Thanks for posting. As someone who has started doing night photography, I have run into this problem. Sodium vapor lamps (which is what I assume you have on the left) are a particular problem, as they are VERY yellow. I had never tried adjusting parts of the image separately. This is a helpful suggestion.

Your latter two images are a big improvement over either of the first two. If I were to choose between the first two, I would opt for the warmer, as the blue snow in the second is a problem. Choosing between the second two is tougher. In general, I prefer the warmer one. For the most part, I think the colors are more realistic, e.g., the snow on the railing in the foreground. However, there is a cost: the sky is a sort of brownish color, whereas it is a nice dark blue-black in the cooler one.

Here is my most extreme example of sodium vapor lamps. This is a 10minute exposure at about 11 PM on a largely unpopulated lake. The night was heavily overcast--note the almost totally obscured star trails. They yellow light on the horizon is the reflection on the clouds of a few sodium vapor streetlights at the other end of the lake, about 5 (9 km) miles away.



Dan

[GrahamS]

Manfred, thanks for posting this - Colin should make it a sticky, as it is very useful for beginners who struggle with white balance. Bravo!

[Shadowman]

I know you shot in RAW, but did you set your WB for any particular lighting situation and how did that appear after you converted your photo? Did WB get anything (snow, particular lights) correct?

[Manfred M]

John - I generally leave the WB setting on Auto, just to see what the camera does in these situations.

This is the "final" version of the image after I finished post - a bit more cleanup, especially dodging and burning.

[FrankMi]

Although I usually prefer a warmer rendition, the third cooler image is, to me, a more natural view of a cold winter night.

An outstanding example of one of the benefits of Post Processing over SOOC Manfred.

[Mike Buckley]

The last one is marvelous. Great job!

[Shadowman]

John - I generally leave the WB setting on Auto, just to see what the camera does in these situations.

This is the "final" version of the image after I finished post - a bit more cleanup, especially dodging and burning.

Thanks Manfred.

[chauncey]

OK Manfred, you've explained what you did...now take us to school and tell us how you did it.

[Rita]

I like the third image because it almost makes a person feel the cold of the night air.

Now a question, what are gels?

[rpcrowe]

Manfred,

First off, IMO, this is a very lovely shot! However I like just about any version that you posted. But, I like the all-over blue of #2 the least. I think that color balance in night shots is simply up to the photographer's/post processor's likes and dislikes and, unless some faces are involved. just about any colors look good. I also like to shoot my night shots using AWB...

I do agree that I like the final version best (great PP job) but, I would be happy with #1, #3, #4 or the final version.

I am confused, though, what all that fluffy white stuff on the ground is It was a bone-chilling 18 degrees C. here last night but we will recover from the cold since it is expected to reach a more comfortable 23 C. today

BTW: Rita, "gels" are clear colored sheets usually placed over the front of a flash tube to change the color of the light from the flash.
http://www.adorama.com/IA144CGK2.htm...Fax_QgodAzUAZw
Most electronic flashes produce a light close to daylight in color. If you are shooting in an area in which the ambient light is a different color (such as fluorescent or tungsten) the area or subject lit by the flash will be of a different color from the background. A gel would be placed over the flash (greenish in the case of ambient fluorescent lighting and amber for tungsten) to shift the color of the flash towards the ambient light. That way, it is easier to work on the color balance for the whole image. You can also use the gels creatively by drastically changing the color of your flash. The term "gel" comes from "gelatin" which originally the colored sheets were mad of. However now, they are made from other composite materials such as plastic.

[Manfred M]

Now a question, what are gels?

Rita - gels are thin plastic coloured filters that you put over your light source to match the colour temperature of the ambient light source; i.e they help fix colour temperature issues in mixed light situations. Flash, for example is colour balanced to matched to daylight at around 6000K.

If you are shooting flash indoors with ambient tungsten light (3500K); applying a CTO (Colour Temperature Orange) over your flash 6000K flash means it will give off the same colour temperature light as ambient and you won't have any strange colour casts in your image.

[Manfred M]

Thanks Richard - it was -18C when I was out shooting; not really all that bad. The week prior we were pushing -30C and that was not a lot of fun. The snow had fallen earlier on that afternoon and was still WHITE!. The problem with snow in the city is that as with anything white, it does get dirty very quickly and grey or brown muddy snow is not particularly photogenic!

[Manfred M]

OK Manfred, you've explained what you did...now take us to school and tell us how you did it.

Technique was not all that difficult. I prepared two panos, one that was correctly white balanced for the lights on the left side of the canal and another one for the right. I had to do this in RAW.

Once the two files were prepared, I brought them into Photoshop on separate layers, aligned the two images and appled a layer mask to the top image. With a soft brush set to around 25% opacity, I painted in the portions of the mask to expose the parts of the bottom layer.

Once I got the image looking right from a colour balance standpoint; I did some dodging and burning and cleaned up the combined images until I was happy with the look.

[chauncey]

While I was posing my question Manfred, I was pondering how I might have done it.
Although I might have worked on the initial RAW images in PS using the color sampler
tool and levels to attain balance...your method appears a whole lot easier.

[Manfred M]

While I was posing my question Manfred, I was pondering how I might have done it.
Although I might have worked on the initial RAW images in PS using the color sampler
tool and levels to attain balance...your method appears a whole lot easier.

The main reason I went this way is that I needed to balance the two main light sources and gently blend where they met. By feathering the transition, I was able to achieve a natural looking blend, much like how our eyes see it.

[dje]

Only just caught up with this tread Manfred. Your final image is just wonderful. Thanks for sharing your technique too.

Dave

[xpatUSA]

An excellent thread, Manfred.

Interesting phrase "much like how our eyes see it".

In the original scene, did your eyes 'WB' the variously lit areas, fully or partially? I ask because the literature mostly quotes a white item under a single source of light; however, a case such as your pano is dismissed as "mixed lighting", "use gels", or something like that. Coming back to the point, do our eyes do a 'double' WB - for example - if simultaneously viewing a halogen-lit white card at left and a mercury-lit white card at right? I suppose they'll do their best, eh?

[Manfred M]

An excellent thread, Manfred.

Interesting phrase "much like how our eyes see it".

In the original scene, did your eyes 'WB' the variously lit areas, fully or partially? I ask because the literature mostly quotes a white item under a single source of light; however, a case such as your pano is dismissed as "mixed lighting", "use gels", or something like that. Coming back to the point, do our eyes do a 'double' WB - for example - if simultaneously viewing a halogen-lit white card at left and a mercury-lit white card at right? I suppose they'll do their best, eh?

I could definitely see that the left side of the canal was "warmer" light than the right, but certainly not to the extent as shows up in the images. According to the literature I've read, the in focus FoV is fairly narrow and our eyes / brain stitch together an impression of the scene that is more balanced than what the camera records. I sometimes suspect that experienced photographers tend to look for these constraints more so than what a casual observer might.

The bottom line is still a mixed lighting situation, and quite frankly that is both the beauty and downside of these night shots. There is no "right answer", so the photographer can interpret in any manner he or she chooses to. Just as an aside; to my eyes the sky background was actually more a purple tone, not the blue that I used in the final image.

[FrankMi]

Another thing I've heard Ted, is that the cone (color) cells in the eye also have a very narrow FoV as well. If I have the facts straight in my mind, 50% of the nerve connections are made to the cone cells in the Fovea, the center of which is only 0.2mm in diameter and sees about a 2° field of view. There are about 6 million cone cells but close to 120 million rod cells that cannot detect color but can be triggered by as few as 6 photons (the cone cells require significantly more light to be triggered).

Outside the Fovea there are scattered cone cells by at an extremely low density. Because of the narrow FoV of the majority of the cone cells, our peripheral vision is provided by the rod cells. As Manfred indicated, the brain remembers the color of what the cone cells saw and applies it to what the rod cells are currently seeing. As a result, in our mind we see color on a much wider FoV than what is available to the cone cells at any point in time.

By comparison to the human eye/brain combination, when we think about exposure, focus, DoF, color, movement and a host of other factors, the camera is limited to one setting of each of these facets for a given image.

For more information, take a look at http://en.wikipedia.org/wiki/Photoreceptor_cell and http://en.wikipedia.org/wiki/Fovea.