Trogon Photo Tours

                                                                             JANUARY 2011 NEWSLETTER

This month's newsletter features additional information on using fill flash for bird photography.  It
addresses how much flash compensation to use when using fill flash.  The November 2010
newsletter has an in depth introduction to fill flash photography and can be viewed here.

 
TOUCAN BARBET photographed December 2007 at Sachatamia Lodge, Ecuador.  Canon 1D Mark III, 500mmF4 lens, 1.4x teleconverter, 1/100 F7.1, iso 1000, evaluative metering -0.3, 580ex fill flash at -1.3.  I most often use fill flash with a negative flash compensation of -1.3 to -1.7.  I would consider this an "average" situation with nothing exceptional about the lighting other than it being a fairly low lit situation.  With my gear and style I find that amount of negative flash compensation (-1.3 to -1.7) in an average situation will usually result in a well lit photo that doesn't look overflashed.  However there are many lighting situations that are not average.

The question of how much flash compensation to use when using ETTL or ITTL flash is not an easy one to answer.  It will depend on several different factors.  With experience using flash in the field you will begin to have a sense of how much to dial in.  I would say in general to avoid an overflashed looking image with most Canon and Nikon gear you will usually want to dial in at least -1.0 flash compensation when using fill flash.  There are of course exceptions which I will cover. 

FACTORS WHICH AFFECT HOW MUCH FLASH TO USE
If you are having trouble with any of the terms here you may want to review the November newsletter which is linked here.

1) Regular versus high speed synch flash - If you are using your flash in regular flash mode (the shutter speed on your ambient exposure is less than the max normal synch speed with your camera) you will need less flash than if you are in high speed synch mode.  Stated another way as you increase your shutter speed past the normal synch speed (usually about 1/300 or 1/250) the faster your shutter speed is the more flash you will need.  The reason for this is that with a fast shutter speed the flash distance and duration is cut down. 

2) Degree that the bird is backlit or frontlit.  Birds that are backlit will typically require more flash (or less negative flash compensation).  Birds that are frontlit will typically require less flash (more negative flash compensation).

3) The distance to your subject.  The farther away your subject the more flash you need to use, the closer your subject the less flash. 

4)  Lens size.  The bigger your lens the more flash you will need to use to make a difference.  Conversely, the smaller the lens, the less flash you will need to use. 

I had the question during a recent tour when I was reviewing this information.  Yes, but if you are shooting
in ETTL or ITTL doesn't the camera automatically adjust for these situations?  My answer was yes and no.  The camera does it's best job to estimate how much flash to use but rarely does it do it perfectly.  This is particularly true when you are mixing flash and ambient light (using fill flash).  As I said before typically you will want to dial in some negative flash compensation in that situation.   The camera and flash do a much better job at estimating the amount of flash to use when you are shooting with no or very little ambient light (such as at night time). 

REDDISH EGRET - photographed August 2008, Dunedin Causeway, Florida.  Canon 1D Mark III, 500mm F4 lens, 2.0 teleconverter, 1/250 F13, iso 640, evaulative metering at 0, 580ex at -0.7.  Angie and I visited Florida for a few days in August 2008.  The main purpose of the trip wasn't bird photography but of course I did some shooting in between visiting Disneyworld and looking at real estate.  We hit quite poor lighting and weather on the trip.  I'd always wanted to photograph this species and found one at close range on a rainy, dark day.  He was quite close to the car so after shooting some full body shots, I elected to take some portraits.   The bird was fairly backlit and it was quite dark so without using flash I would have had to blow out the water background to get the bird properly exposed.  I ended up using more fill flash than usual (filling at -0.7) due to the combination of the bird being backlit and using a lot of lens (1000mm). 

BLUE-WINGED MOUNTAIN TANAGER - Photographed January 2010 at Sachatamia Lodge, Ecuador.  Canon 1D Mark III camera, 500mmF4 lens, 1.4x teleconverter, 1/300 F8, iso 400, evaluative metering at -0.7, Gitzo tripod, 580ex fill flash at -2.3.  This bird was frontlit but the lighting was dappled and the background was a little bit bright.  To even out the contrast I used some fill flash but not a lot as the bird was front lit, I was fairly close to it and I was in normal flash mode (my maximum normal synch speed for my camera and flash is 1/300).  Note also the negative exposure compensation that I used to bring down the background and keep from burning out the yellows. 

RINGED KINGFISHER - photographed January 2010, Sani Lodge, Ecuador.  Canon 1D Mark III,
500mmF4 lens, 1.4x teleconverter, 1/1000 F7.1, evaluative metering +1.7, 580ex fill flash at +3.0!  I photographed this Ringed Kingfisher at Sani Lodge on a foggy morning.  Because I was shooting handheld from a canoe I needed to keep my shutter speed up.  In addition the bird was very back lit against bright gray/whitish sky.  I kept bumping up the amount of flash I was using as it didn't seem to be making much difference in the image.  Luckily, I had a cooperative subject.  This is the one situation you will often add flash compensation rather than subtract it, when you are shooting a subject with a fast shutter speed (and using high-speed synch flash) that is against a bright sky.  It's more common to use these positive flash compensations with flying birds against a bright sky - then you have the added issue of the bird not being very close to you.  It's possible my flash batteries were getting a bit low here and that was part of the reason I needed to add so much flash. 

In the end the amount of flash compensation you end up using on any given image is going to depend on your personal style, your gear and the factors that I listed above.  As you gain more and more experience with flash you will begin to know about how much flash compensation to dial in each time.  For example I most often use a flash compensation of -1.0 to -2.0.  You may find with your gear and style you prefer something more like -2.0 to -3.0.  Review your images on the back of your lcd when in the field and on your computer when you get home and adjust according to the feedback that your images are giving you.  Try to aim for an image that is natural looking but also shows the colors and plumage of
the bird well.