I don't understand!!!!!!!!!!!!!!!

binglemybongle · Dec 14, 2005

I recently got a Canon Eos 30 (Elan 7e).

I've had a bit of a play around with it and shot a roll and all seems fine.

But i don't understand how the built in flash works.

I understand in so much as you have to raise it manually when in the 'creative modes' but my problem is the following:

(The following is of a subject that the camera has no trouble focusing on and with 2m of the flash)

In program mode:
If there is poor lighting, for example viewfinder reads - f4 @ 1/10 sec,
then i raise the flash, it then reads f4 @ 1/60. The flash fires and the picture taken.

If in Av (manually set aperture, automatic shutter speed):
If it reads f4 @ 1/10 then i raise the flash it stays at f4 @ 1/10 but the flash fires when picture is taken.

In Tv (manually set shutter speed, automatic aperture):
f4 and anything faster than 1/10 sec and it warns that is not going to result in exposure. f4 @1/10 it reads ok. Raise flash and it stays the same. The flash fires when picture is taken.

Why does it recognise that there will be more light falling on the subject if the flash is raised in Program but not in Av or Tv???

In Av and Tv, are they being over exposed?

Are they being taken at different settings (equivalant to that of the program), known to the camera but not displayed in the viewfinder?

Am i being a simpleton?!

photoboy15 · Dec 14, 2005

It should recognize it on Av mode but not on Tv. It should go to 200, or whatever the camera sync speed is, at what ever f stop you set it at in Av. At least thats what it is suppose to do, but Ive only used ex ez flashes I have not had the built in on. The reason it dose not work in Tv mode is that you are setting an shutter speed and the camera is setting the f stop according to the meter in the camera. So if the sync speed is 200 then setting a different shutter speed would be useless. Like I said I have not used a pop up flash so this could be wrong, but it should be similar to the hot shoe flashes.

binglemybongle · Dec 15, 2005

Does anyone else have an EOS 30 (Elan 7e) and know what i mean with the pop up flash in Av & Tv.

As a secondary thought, i have an old Speedlite 277T. Can i still use that?

santino · Dec 15, 2005

as far as I know the built in flash can't be controlled, it is just firing in it's usual way (always same power) and as far as I know it doesn't work with the "creative stuff". If you had a speedlight it must work.

binglemybongle · Dec 15, 2005

santino said:
If you had a speedlight it must work.

Even if its the 277T?

I know its a speedlite but its about 15 years old or something. Im sure it will fire but just wondering if it will work properly as in does it use the same interface(???) as a modern speedlite?

Still, what i want to know is why the camera doesnt recognise in Av and Tv that there will be more light falling on the subject when the builtin flash is use, like it does in program mode.

photoboy15 · Dec 15, 2005

Have you read the manual? How did the pictures look after you have shot in the modes with the flash? Some of the Canon cameras have custom functions that need to be set for the Av mode to auto set to the sync speed. As for the the sepedlite I don't know if that is a EOS TTL model.

Big Mike · Dec 15, 2005

Read this, it's been called the EOS flash bible.

DocFrankenstein · Dec 15, 2005

They don't publish the damn algorithms for the cameras, so everybody always has problems with flashes... even people with DSLRs with instant feedback. "help, what do I do? background blurry? Flash over/underexposes!" And a lot of people just switch their 500$ wonderflashes to manual when they shoot weddings.

Good luck figuring it out with film!

And your external flash won't communicate with camera.

I didn't like the complexities of ETTL and ETTL II metering and got myself a vivitar with auto thyristors and fully manual controls. Try them. Pretty much the same thing as the expensive 550/580 if you use them in manual mode, but you don't get fast recycle times and AF assist light.

Vivitar 283/285 was one alternative I found.

Hope this helps

binglemybongle · Dec 16, 2005

Big Mike said:
Read this, it's been called the EOS flash bible.

When i saw this post i assumed it would be a few helpful paragraphs regarding flash........... I see now why you've called it the bible, It's frigging massive!

If this doesnt help, i don't know what will. If i still have problems after reading, i may give up on photography and take up fishing!

Beware TFF (TheFishingForum).

Marctwo · Dec 16, 2005

This is quite normal and lets you use AV mode for fill-flash without the background being underexposed.

If the shutter gets to slow, I just switch to manual.

binglemybongle · Dec 16, 2005

Marctwo said:
If the shutter gets to slow, I just switch to manual.

So how does that work?

If for example (wihtout flash) in Av mode at f4 the camera decides on 1/10 shutter speed and i switch to manual and (at f4) and set the shutter to 1/30 sec (with the flash up) what happens?

Will the camera set the flash to expose the foreground perfectly and ignore the background?

Will it try to approximate for the whole scene, underexposing the background and over exposing the foreground?

Will i have to set the flach speed to match the shutter speed?

I've looked in the manual but it has about 1 paragraph and it's very vague about the built in flash.

On the other hand it has about 10 pages on the ex flash range. Nothing like about bit of after market sales to boost profits!

Marctwo · Dec 16, 2005

The flash will take care of lighting the forground subject while the shutter speed will set the exposure for the background. In this case, the bg will be a bit underexposed but may well look fine.

It boils down to a compromise between exposing the bg properly and having a practicable shutter speed for the situation. In many cases a 1/10 shutter would be ok as the flash helps to freeze the forground to some degree.