New 40D user needs flash help

magicman320 wrote in post #6076369
The answer is yes. Nikon works extremely well in Aperture Priority. I did a wedding and i was using canon 40D and the other two shooters had D300's. They shot aperture priority most of he night when i couldnt. I had to shoot manual.

90% of my flash photos are using fill mode...unless I use studio strobes...specially for back lit subjects...you probably forgot to use HSYNC (HSS page 17 of the 580EXII manual)...some folks hate it...I love it...

"M" FTW!!!

silvex wrote in post #6076469
you probably forgot to use HSYNC...some folks hate it...I love it...

Tell me how to do that..

Actually, you can use AV on Canon cameras and get just fine flash results........if you set the EC to about -1 1/3 to -2. It is much better to use M on the camera though, since a black suit or white dress will fool the meter.

My guess is that is what the Nikon shooters at the wedding were doing (setting the EC to underexpose). That is unless Nikon makes their cameras that amazingly idiot proof that either locks the shutter speed no matter what mode you have the camera in when a flash is attached or automatically sets the EC to underexpose the ambient.

Re: High-speed sync (HSS)

magicman320 wrote in post #6077722
Tell me how to do that..

Press the HSS button on your 580EXII. It's the 3rd button from the left in the row of 4 buttons. It's between the MODE button and the ZOOM button.

Or RTFM p. 17 if you can read English.

40Dude6aedyk wrote in post #6077873
Or RTFM p. 17 if you can read English.

ありがとうございました = Thank you in japanese

silvex wrote in post #6076469
90% of my flash photos are using fill mode...unless I use studio strobes...specially for back lit subjects...you probably forgot to use HSYNC...some folks hate it...I love it...

40Dude6aedyk wrote in post #6077873
Re: High-speed sync (HSS)

Press the HSS button on your 580EXII. It's the 3rd button from the left in the row of 4 buttons. It's between the MODE button and the ZOOM button.

Or RTFM p. 17 if you can read English.

What in the world will HSS to to fix a shot ruined by using too low of a shutter speed?

And was that really necessary 40Dude? Silvex stated (and magicman asked about) HSYNC, which if searched for in the manual will come up with nothing. If silvex had said HSS (which it is officially and commonly referred to), your offhand comment might be warranted.

Also, lets get away from calling AV "fill mode". What is happening in AV is that the camera is attempting to capture a good ambient exposure, while the flash is trying to also expose the scene properly. When your ambient lighting gets too low, the camera must use a very slow shutter speed to get the ambient exposure correct. If the flash fires, it's duration is very fast (around 1/800s), giving you a properly exposed flash exposure mixed with a properly exposed ambient exposure. With a shutter speed of 4/10s, your subjects are going to blur if they are moving. This is what happened in the posted photo. You get a somewhat sharp flash exposure mixed with the blurry ambient exposure

If it had been daylight and your shutter speed was at 1/1000s and HSS was enabled (to allow the flash to sync with the camera at speeds faster than 1/200s or 1/250s, depending on the camera), what you end up with is a properly exposed ambient and flash exposure. They will be roughly equal and very few shadows will show.

Fill flash is used to fill in harsh shadows, and if done correctly will result in a properly exposed ambient exposure, with an underexposed flash exposure (usually around -1 to -2). This "fills in" the harsh shadows. This makes for a more interesting image because there are still shadows to show contrast and features, but the detail in the shadows are not completely black, as would often happen in harshly lit (bright daylight) situations.

These are samples of HSYNC...Ooooops... HSS...yes I meant HSS...HSS...
1/1600 f/4.5 ISO 400 100mm

HTTP response: 404 | MIME changed to 'text/html' | Byte size: ZERO

HTTP response: 404 | MIME changed to 'text/html' | Byte size: ZERO

HTTP response: 404 | MIME changed to 'text/html' | Byte size: ZERO

am i right in thinking the built in flash on the 40d doesn't support hss? Just up to 1/250? I'd love it to do that, for those occasions you're out and about without external flash but want a touch of fill on a sunny day.
Built in master controller would be nice too

mrklaw wrote in post #6079699
am i right in thinking the built in flash on the 40d doesn't support hss? Just up to 1/250? I'd love it to do that, for those occasions you're out and about without external flash but want a touch of fill on a sunny day.
Built in master controller would be nice too

Correct... no HSS in inbuilt flash.

I'm not a big fan of it myself. It drains batteries like there's no tomorrow and I hate to think what it is doing to the flash tube since it fires it at much higher power than in usual operation (granted it is for a much shorter period of time... but still :confused

silvex wrote in post #6079620
These are samples of HSYNC...Ooooops... HSS...yes I meant HSS...HSS...
1/1600 f/4.5 ISO 400 100mm


1/800 f/5.6 ISO 400 400mm


1/6400 f/1.2 ISO 100 85mm

Yep, all outdoors in the sunlight with very fast shutter speeds. HSS is about your only option in these shots.

Not sure if you noticed, but the OP was indoors with a SS of 4/10s. HSS really has nothing to do with this discussion, no matter what you call it.

DDCSD wrote in post #6080939
Yep, all outdoors in the sunlight with very fast shutter speeds. HSS is about your only option in these shots.

Not sure if you noticed, but the OP was indoors with a SS of 4/10s. HSS really has nothing to do with this discussion, no matter what you call it.

Someone ask how to do it and reason for my answer. Also the 580 X II will sync is the shutter speed is under the cameras flash sync speed. In the 40D's case it is 250.

So if you are shoot in Av mode this is my sort of "safety flash switch" so I will not get dark images.

photobitz wrote in post #6080099
Correct... no HSS in inbuilt flash.

I'm not a big fan of it myself. It drains batteries like there's no tomorrow and I hate to think what it is doing to the flash tube since it fires it at much higher power than in usual operation (granted it is for a much shorter period of time... but still :confused

Ummm, somehow that doesn't sound right. An arc discharge in gas (which is what we have in a flash unit) has its characteristic intensity for a given flash tube size and can't be brighter or dimmer. The voltage needs to be high enough to ionize the gas, and once it's ionized the voltage can't rise above that point. The current (and, by derivation, power) in the flash is determined by the discharge voltage of the gas and its characteristic impedance. The source impedance of the flash power supply is very, very low - the current comes from a large capacitor.

So-called higher power flash is really longer duration. HSS flash fires multiple times, as I understand it - obviously many flashes will drain the battery faster than a single one of the same duration.

Is there something I'm missing here?

-js

No, you are dead on, number six. But your avatar looks more like Super Seven.