Difficulty understanding the concept of flash.

[dearis]

Hi there,

today my wife and I expored the zoo with my new camera(well 2 months old) and aside from the fact my 580ex batteries ****e themselves after an hour, was just wondering how I use flash to create a faster shutter speed?

or is it the camera that controls it? the lense I was using was mainly my 70-200mm F/4 L. amd ,y 100mm F/2.8 Macro however I also have the MT24-EX macro flash but thats another story :)

Regards Darren

[coreypolis]

you need to read up on high speed sync if you want to have a fast shutter speed (more than 1/200). you enable this on the flash


without it, the camera limits the shutter speed to the max sync speed, which is 1/200 on your cam

[lederK]

I guess you are talking about how to freeze movement using flash. This can be done if the flash is the only significant light for your scene. Since the flash fires a light pulse that lasts typically for 1/1000 of a second or less and short exposure times can be achieved since the scene is only illuminated during this pulse. Thus you may freze movement if the ambient light is so low that an exposure without flash but at the same shutter speed and aperture renders a (nearly) black shot. If you then switch on the flash, the exposure time will be the same as the length of the flash pulse and independent of the shutter time.

On the zoo however, I would expect the ambient light to be your main light source and thus the exposure time is dependent on shutter time. In this case you cannot use the flash to freeze movement. Short shutter times with flash can be reached (as coreypolis pointed out) by high speed sync.

HTH

[stupot]

high speed sync

yeah but thats fill flash which prob isnt that useful...

if you're looking for faster shutterspeeds at a zoo you're either there at night or in the bat enclosure! in which case stick your camera in manual mode. choose a shutterspeed and aperture. your shutterspeed will not affect how much FLASH light the sensor receives, it will affect how much AMBIENT light the sensor receives. your aperture will affect how much flash gets to your sensor. experiment a bit when you're there, stick your camera on say 1/200s and aperture f/4 or something. if the flash is on ettl it will do the maths for you and adjust the power of the flash to suit. if your shots are coming out underexposed it is because the flash is not powerful enough - so either open up the aperture or increase the iso. you can do this anyway if you want to speed up the recycle times.

[tim]

Unless you're at the zoo at night there should be plenty of natural light, so forget the flash. Instead make sure you use wide apertures and higher ISO if necessary.

Think of a flash as letting you add light where it's needed. A little flash like a 580 can't often overpower the sun, especially at anything like the ranges used at the zoo. Even powerful studio units could have trouble with that.

[Curtis N]

how I use flash to create a faster shutter speed?The question is, "faster than what?"

Flash is commonly used indoors, where shooting with ambient light only would require a slow shutter speed for proper exposure. I'm guessing this is what you're after.

Click the link to "Flash Photography 101" in my signature. Once you're wrapped your brain around the concepts in that article, feel free to ask if you have additional questions.Unless you're at the zoo at night there should be plenty of natural light, so forget the flash. Most zoos have lots of indoor exhibits with generally poor lighting.

[dearis]

Hi there,

well the Melbourne zoo is also botanical gardens, as you wander past an exibit for say asian tiger, you walkthrough think rainforrest to get there there fore light for that enclosure is very low even on a bright sunny day. I shot in AV mode mainly and for the most exposed well, however some shots at f4 were very shaky, with flash on, was wondering why i couldn't even get 1/200sec?

th see each species enclosure you need to walk through jungle, i really is a wonderful place :)

Regards Darren

[tim]

Most zoos have lots of indoor exhibits with generally poor lighting.

Yep, but the reason the lights are bad is usually because that's the way the animals like it. There's usually no flash photography allowed.

[Curtis N]

I shot in AV mode mainly and for the most exposed well, however some shots at f4 were very shaky, with flash on, was wondering why i couldn't even get 1/200sec?Av mode is designed to meter for ambient light. Same for Tv and P. If you don't want ambient light to contribute significantly to your image, there's no point in using those modes.

To attain a faster shutter speed with flash than you would get without it, the best way is to switch to Manual mode. Take control.

Using Manual mode, with the shutter at flash sync speed, is a way to tell the camera, "I don't care about the flippin' ambient light, I want my flash to do the work."the reason the lights are bad is usually because that's the way the animals like it. There's usually no flash photography allowed.Apparently, the rules vary. I was at a major zoo near Chicago a few weeks ago, flashing all over the place.

[dearis]

Ok I start shooting at manual, aside from experience do do i know whats what?

and If i start shhoting raw and in manual, i can fix my stuff ups is that right?

Regards Darren

at melbourne zoo certain exibits are flash free! and most are not

[Curtis N]

Ok I start shooting at manual, aside from experience do do i know whats what?If you read Flash Photography 101 and work to understand those concepts, you'll be better able to learn as you go. The effective range of your flash unit depends on the power of the unit, your aperture and ISO setting. With direct flash, the distance scale on the back of the flash unit will help guide you. You need to understand the concepts first, in order to adjust for each circumstance.and If i start shhoting raw and in manual, i can fix my stuff ups is that right?RAW is good. It will give you some lattitude, but it's still best to get the exposure right when you take the shot.

[dearis]

Curtis Thanks for that,

I will seek out a site for 1 on 1 thanks for thst, also there is not a chard on my flashes.

Regards Darren

[Curtis N]

also there is not a chard on my flashes.There's either a typo in there, or I need an Australian-to-American translator. What's a chard?

[jrsforums]

There's either a typo in there, or I need an Australian-to-American translator. What's a chard?

Risking a try at translation....I think he meant 'chart'....looking for the distance info.

Darren, the distence info is displayed, on the 580EX, at the bottom of the flash LCD....default is meters, can be changed to feet.

John

[dearis]

sorry i meant chart curtis....lol...typo!

[InspiredGraphix]

Curtis Thanks for that,

I will seek out a site for 1 on 1 thanks for thst, also there is not a chard on my flashes.

Regards Darren


Darren,

I think Curtis may have been referring to this thread (which is Curtis' thread):
http://www.photography-on-the.net/forum/showthread.php?t=171657&highlight=flash+101

It is a great resource if you are trying to understand the basic concepts of flash.

Rob

[René Damkot]

Set a higher ISO, and use flash as fill only...

[dearis]

Thanks for that :)