how to shoot w/ flash at night?

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forestgnome

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How would you handle such a situation? Twice now, I've forgotten to try the "A-DEP" option on my Digital Rebel, (cubs in a tree last time). I shoot the night sky often from a tripod, but of corse this is different. I'm going to experiment tonight with the "A-DEP" option, which is what the manual instructs.

This was well after sunset, no chance at all without flash. BTW, I use the on-board flash, no external flash. What would you do?

5-02-07-036.jpg


Happy Trails :)
 
A dedicated (Hot Shoe) flash will help reduce red eye (or in this case green eye ;) ). You could also try a diffuser depending on how far you think you might get from the subject. Many Dedicated flashes have pre fit diffusers for them. This would make the lighting less harsh giving you a more natural looking subject (as opposed to the limited shadow, high contrast picture.) The biggest probalem with a diffuser is it cuts down you maximum range. But as I understand your skill as a Moose stalker, you should have little problems getting close enough :D .

Brian

P.S. They also make a unit that allows you to move the Dedicated flash off the camera, but still get the TTL sync. This will allow you to get better shadow control and thus less "flat" pictures.
 
The other thing to think about when night shooting with a flash is first or second curtain synchronization. With the stock Rebel you have no choice, you get first, but this info may be helpful to others.

The difference is basically whether the flash fires when the shutter first gets open, or when it's about to close.

For short shutter speeds, you won't notice a difference. For night shots, however, with longer (manually set) shutter speeds, it can make a huge difference.

The easiest is to imagine something in the foreground moving past you in the dark. With no flash, the long exposure will capture the background and cause motion streaking of the foreground. Include a flash and you still get the background exposed and the object's streaks, but you also light up and freeze the foreground object at one instant in time.

Now ... where are the streaks?
With first curtain, the streaks start from where the flashed object is and continue from there.
With second curtain, the streaks end at the flashed object.

You can do some very cool things with night shots combining flash and long exposures.
 
Flash as primary light source at night can be tricky, tricky, tricky.

The inverse square rule applies. That rule says, “as flash-to-subject distance doubles, light intensity drops to one-fourth.”

Using any flash control system that factors in focusing distance, what this generally means is that foreground objects (closer than the point of focus) will be “burnt up” while those in the background will be underexposed and obscure. As flash-to-subject distance decreases, this effect becomes increasingly evident.

Even (consistent) lighting in depth is nearly impossible to achieve in a single shot from a single flash located at or close to the camera position.

Now, looking at the photo of the moose …

The overall exposure seems to be OK, but the picture is not satisfying on two key points.

1) The bright eyes. What you actually see here is a reflection of the flash from the retinas in the moose’s eyes. The animal’s wide-open pupils exaggerate and aggravate the problem.

2) Lack of “modeling” that yields a very “flat” or two-dimensional looking rendition of the animal. Modeling is the interplay of highlights, midtones and shadows in the subject that gives a sense of the third dimension. Note that the only real shadow we see is a sort of dark outline of the moose’s body, just to the right of the moose’s body.

Both of these things result from the flash being mounted on the camera, very close to the lens axis. So …

The biggest single improvement that could be wrought here is to get the flash off the camera.

To do this, you will need to use a separate, rather than built-in flash. My own kit (Nikon gear) includes a heavy-duty coiled cord that will stretch out nearly 6 ft to connect the flash unit to a camera, while preserving all the automated flash and camera functions.

Some people use specialized brackets to mount the flash unit well off the lens axis. An example can be seen here.

I use my hand and extended arm to hold the flash away from the camera -- usually up and off to one side. Or sometimes I get help from a glamorous assistant, like Mrs. Grumpy.

Another trick that I hesitate recommending or even suggesting is to use some kind of diffuser to “soften” the light from the flash. These typically are translucent plastic devices, but a white handkerchief or facial tissue can be used as well. Just drape it over the flash head, and hold it in place with a rubber band if need be. The problem is, these invariably reduce the intensity of the light, which can be a disadvantage at night, outdoors. The trouble with outdoors is that we usually don’t have good reflective surfaces to “bounce” light back into the scene. It just dissipates .... That’s another part of the tricky, tricky, tricky business.

G.
 
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Thanks for all the comments so far. I probably won't go for the external flash because I won't use it very often, and I won't want to pack one. I'll settle for however the shadows look when I shoot wildlife at night. In this case I'm just trying to capture what I saw. I don't do any studio work, etc., so I can't prioritize a flash purchase.

My question is how to focus when you can't see through the viewfinder well enough to focus. I took 78 shots of this bull, 2 are in focus. :eek: . The "A-DEP" option is supposed to render the whole field in focus while keeping the flash in snyc with the shutter. I'm going out to try it right now. Has anyone used this option? Any feedback appreciated. I'll report on results.

Happy Trails :)
 
I have done some experiments in low light photography with my Digital Rebel. Open area at night with no moon, open area at night with moon etc. You will need a tripod, but one can do quite a lot with exposures up to a few seconds.

You can also use the flash to illuminate the scene well enough for autofocus and then turn it off before taking the shot. I have also illuminated a target at ~80 ft with a headlamp to get the autofocus to work.

Doug
 
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forestgnome said:
... My question is how to focus when you can't see through the viewfinder well enough to focus. I took 78 shots of this bull, 2 are in focus. :eek: . The "A-DEP" option is supposed to render the whole field in focus while keeping the flash in snyc with the shutter. I'm going out to try it right now. Has anyone used this option? Any feedback appreciated. I'll report on results.

Good luck with the automated "A-DEP" function. I'll be interested to read about your results.

Here are some alternatives to consider.

Some flash units have an autofocus assist illuminator. Read your owner’s manual to see if yours has this feature and learn how to use it if it does.

For decades, my working photo kit has included a small, high intensity, focusable-beam flashlight (MagLite, 2 AA cells) that will throw enough illumination in many conditions to give me something (a lighted circle) to focus on. A more powerful light might be better under some conditions.

Don’t forget to lock the autofocus mechanism once focus is achieved. If you don’t it may continue to search and take you out of focus when you move the camera to adjust composition.

Manual focusing might work better for you than the autofocus mechanisms – both in achieving focus quickly in the first place and staying locked in focus in the second.

You might try manual pre-focusing, in which you set your focus at a likely distance and fire away. Or, use zone focusing, using one of the depth-of-field optimization tricks discussed earlier.

Downside in pre- and zone-focusing techniques is that you usually need to shoot at a smaller f/stop to maximize DOF, and your flash may not have enough power to illuminate a subject at any distance. (Also, in your case, animal fur is notorious for “soaking up” light and not reflecting it back, resulting in underexposure.)

I often use “manual” exposure mode when shooting with flash at night, setting my shutter speed fairly high (at or near the upper end of the range at which it will synchronize with the flash without using any fancy tricks) and the f/stop fairly open (around f/4 – f/5.6). Experiment to find out what works best with the equipment you have and in the kind of photography you are doing.

As said before, night photography with flash is tricky, tricky, tricky.

G.
 
Grumpy said:
Some flash units have an autofocus assist illuminator.

The Canon external flashes do. My Speedlite 420EX produces a pattern of red lines which is supposedly best for the focuser, which is trying to optimize contrast along edges. It works very well in the otherwise-dark.

The Canon Rebel built-in does a strobing pre-flash for autofocus. Ick.

BTW, while we're talking Canon equipment, if you want to get your flash totally off the camera body, most of their line of flashes can be used as remote slaves, while on the camera you have to put either one of the higher-end flashes which can be an infrared master, or a standalone master. I've used both setups and they're fun. It's amazing how different a shot becomes when the flash isn't coming from the direction of the camera.

Nikon users, your cameras communicate to the flashes through strobing. It means an unfortunate pre-flash but it also means that the camera body's internal flash can be your master.
 
Update...

Well, I didn't experiment until I was shooting another bull moose at night. :eek: The "A-DEP" option did not work. I'm guessing the problem is the non-kit lens. I'll break down and read the manual tonight.

I like Dougpaul's idea about using a headlamp to focus. It might be enough to do the trick.

Grumpy and DP, good call on the manual focus. I usually manually focus anyway. I also like the idea of a piece of cheesecloth draped over the flash. I'll try that and I will try the A-DEP function tonight.

In the shot below, I just kept shooting, slightly adjusting focus with each shot. The problem there is that the one shot in focus might not be the one I wish was in focus!
5-11-07-028.jpg


Another question; doesn't the shutter speed need to be either 60 or 90 to be in synch with the flash?
 
"Another question; doesn't the shutter speed need to be either 60 or 90 to be in synch with the flash?"

The top synch speed for the Rebel XT is 1/200. You can fix this as the shutter speed in AV mode with one of the "custom functions". ( at least with the XTi, pretty sure the same function is on the XT)
 
Tim Seaver said:
"Another question; doesn't the shutter speed need to be either 60 or 90 to be in synch with the flash?"

The top synch speed for the Rebel XT is 1/200. You can fix this as the shutter speed in AV mode with one of the "custom functions". ( at least with the XTi, pretty sure the same function is on the XT)

On the XT also. Custom Function 3.

Kevin
 
forestgnome said:
... Another question; doesn't the shutter speed need to be either 60 or 90 to be in synch with the flash?

What we need to know first is that flash synchronization (synch) means the flash will be at its highest power (brightest) when the shutter is fully open to expose the full frame of film or electronic sensor.

There is no universal answer to this question about synch speed. It varies from one camera model to the next. Best advice is to read your camera manual.

(I shoot with one Nikon digital SLR camera that synchs with flash to 1/500 sec; the other camera I use is a newer Nikon model with a top synch speed of 1/250 sec. I do note that in low light conditions both cameras default to a shutter speed of 1/60 sec when I attach a flash unit and turn it on if I am shooting in aperture-priority mode with no other special settings.)

(Older film cameras that use focal plane shutters sometimes have a flash symbol next to the highest shutter speed at which the flash will synchronize. Use that or any lower shutter speed and you will be OK. Most cameras that use leaf type shutters will synch with flash throughout the full range of shutter speeds.)

One thing to remember is that the duration of the flash burst is the primary controller of exposure duration in flash photography. Electronic flash units ("strobes") fire at high speeds -- 1/500 sec or less flash burst duration. The Nikon SB-800 unit that I use fires at a range of 1/1050 sec on full power to 1/41600 sec at 1/28 power. This is what gives flash such great ability to "freeze" moving subjects or negate the effect of camera shake.

But -- and there always is a "but" -- things can become a little more complicated using flash when there is a fair amount of ambient or existing light, and/or you shoot at a high ISO film or sensor setting, and/or you use a relatively large lens opening (low f/number). Any of the three can complicate, but in combination they can complicate matters quite a lot.

In this case what happens is that if either the camera or subject moves, a blurred "ghost" image may appear in the picture. It can be notably distracting in some cases. In other situations it can add a sense of movement or dynamics to the photo. A lot depends on what is blurred and where the blur lies.

I shoot a lot of sports using flash to supplement available lighting, and so blur can be a real problem at times. The most distracting blur has a sharp image with blur leading out of it toward where the pictured action ended. It just looks distorted, distracting and "amateurish." Put the blur behind where the action ended, and you sometimes get a nice effect that helps emphasize the motion / action.

Luckily, many modern SLR cameras have what they call a "rear curtain synch" option which has the flash fire at the end of the time the shutter is open rather than at the beginning. Rear curtain synch puts any blurred existing light exposure behind the action, where it either adds to the effect or is minimally distracting.

Some of these cameras also have a "slow" synch mode in which the exposure is based on rendering the background naturally and the flash is used to illuminate a less lighted subject in the foreground. My camera enables this feature for shutter speeds as slow (long) as 30 full seconds.

Using flash to supplement exisiting light is a powerful technique for producing very striking photographs. I'm not sure it applies much to the forestgnome style of prowling the woods for shots of moose in full dark, but may be useful in a lot of other outdoor photo situations.

BTW, the latest forestgnome moose appears underexposed, to me. Exposure appears to be better -- and probably the flash control system based its readings on -- the tree in front of the moose. Underexposure also may result from being out of or near the limits of the range for the flash unit's output.

Using flash outdoors at night is tricky, tricky, tricky business. Or has that been said before? :eek:

Sorry to ramble on about this. There just is so much to know, and share ...

G.
 
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