Canon 430ex flash in manual with Av

01/08/2008 01:49:46 PM · #26

the camera set at AV doesn't allow you to SET/CHOSE a shutter speed.

the camera doesn't know the flash is in high speed sync because it's set at manual.
all the camera knows is that there is a flash attached... so ( i think ) the camera 'should' default to the x-sync speed ( 1/200 - 1/250th ) NOT 1/4000th.

you could sort of average the light that's coming in, dial in a fast shutter in TV - that also gives you an average of the aperture you're after - and adjust the exposure comp from there.

i think you are asking the camera to do something it wasn't trained to do.

but i am only speculating - and trying the different settinsg at the same time.

01/08/2008 01:55:19 PM · #27

Originally posted by soup:

the camera set at AV doesn't allow you to SET/CHOSE a shutter speed.

Agreed, but it shouldn't lock into one shutter speed either

Originally posted by soup:

the camera doesn't know the flash is in high speed sync because it's set at manual.

My camera does. The moment I hit the high speed sync button on the flash (in manual mode), the camera switches from 1/200 to 1/4000 (1/4000 is the camera's max shutter speed)

Again, thanks for you help. If I'm missing something ... well ... I'm still missing it

:)

Message edited by author 2008-01-08 13:55:53.

01/08/2008 02:07:02 PM · #28

my camara ( in AV )locks the shutter at 1/200th when i turn on high speed sync on the flash and stays there when i turn HSS off...

you can adjust the aperture to get the proper exposure, you can adjust the exposure compensation to get the correct exposure, you can adjust the flashes power/zoom to get correct exposure, you can adjust the ISO to get the correct exposure.

the camera knows there is flash attached. you are telling the flash to work outside of the camaras control. the camera is letting the flash do it's thing, but also should lock itself at the sync speed IMO. it actually makes for an easier time dialing in the correct flash power and zoom. but i mostly shoot in full manual.

you can't adjust the shutter speed in Av, and it makes perfect sense to me why it 'might' lock at the sync speed. it makes none why it would lock at 1/4000th...

maybe call the canon techs?

my take is it might 'be' designed that way ( the 1/4000th thing ) - but it shouldn't be.

if it is designed that way - it's a glitch that they ought to offer a firmware upgrade to resolve...

Message edited by author 2008-01-08 14:07:20.

01/08/2008 02:11:17 PM · #29

a side note - i'll likely move to nikon speedlites this year and continue to shoot with canon cameras... though i probably hang on to the canon speedlites as well... ugh !

see my frustration here:

//www.dpchallenge.com/forum.php?action=read&FORUM_THREAD_ID=722645

01/08/2008 02:35:26 PM · #30

I just checked my gear (350D Av mode @ 5.6 ISO 100, 300mm, 430EX manual @ 1/64) and am getting the same result.

I aimed at ceiling light in my office to simulate bright outdoors shot.

With flash turned off:
1/800th @ 5.6 = correct exposure
Flash on:
1/200th @ 5.6 = overexposure
Flash on (high speed sync):
1/4000th @ 5.6 = underexposure

I tried changing metering (didn't work), program mode (same results)...

I got nothing...except to say you aren't alone...and if you ever figure it out, pass the word along.
-drew

01/08/2008 02:39:05 PM · #31

Why would it lock the shutter at all? Av mode should determine the proper shutter based on the aperture you choose ... not lock it in at anything

Originally posted by soup:

my camara ( in AV )locks the shutter at 1/200th when i turn on high speed sync on the flash and stays there when i turn HSS off...

01/08/2008 02:40:07 PM · #32

happy to read I'm not going crazy

:)

Originally posted by drewbixcube:

01/08/2008 02:48:11 PM · #33

Originally posted by hopper:

happy to read I'm not going crazy

:)

Unfortunately when I was organizing my camera bag (lightening it to carry around) I took out all my manuals, so I can't read up on camera or flash when in Av mode (Pocket guide doesn't say anything about external flash).
-drew

01/08/2008 02:57:52 PM · #34

because the camera knows there is a flash attached, but doesn't necessarily know that the flash is in high-speed-sync. or that it is at any given power setting. better to lock at the known sync speed than screw up the exposure...

set it to ettl and see what happens.

Originally posted by hopper:

Why would it lock the shutter at all? Av mode should determine the proper shutter based on the aperture you choose ... not lock it in at anything

Message edited by author 2008-01-08 14:58:45.

01/08/2008 03:05:55 PM · #35

Originally posted by soup:

set it to ettl and see what happens.

It will expose correctly but will use preflash which OP doesn't want to possibly alert animal subjects to his shot.
Edit: "It, not I"

Message edited by author 2008-01-08 16:16:29.

01/08/2008 03:23:15 PM · #36

my point was - the camera and flash are communicating on a different level in ettl...

Tamron SP AF 28-75mm f/2.8 XR Di for Canon

01/08/2008 04:22:13 PM · #37

Originally posted by soup:

my point was - the camera and flash are communicating on a different level in ettl...

Ok so I looked at it again with flash set to ETTL:

(350D Av mode @ 5.6 ISO 100, 300mm, 430EX ETTL)

I aimed at ceiling light in my office to simulate bright outdoors shot.

With flash turned off:
1/800th @ 5.6 = correct exposure
Flash on ETTL:
1/200th @ 5.6 = overexposure with preflash then flash
Flash on ETTL (high speed sync):
1/800th @ 5.6 = correct exposure with preflash then flash

SamDoe1

Canon EOS-350D Rebel XT

01/08/2008 04:28:08 PM · #38

Originally posted by drewbixcube:

Originally posted by soup:
set it to ettl and see what happens.

It will expose correctly but will use preflash which OP doesn't want to possibly alert animal subjects to his shot.
Edit: "It, not I"

If that's the case then he shouldn't worry. The preflash and main flash are so close together that you'd hardly be able to tell that there was a difference. The only problem the preflash gives is when triggering optical slaves.

With that said, I'll do some tests when I get home and post what I find with my flash.

01/08/2008 04:30:07 PM · #39

I think he was also wanting to shoot rapidly and not have to wait for recycle times.
-drew

01/08/2008 05:23:33 PM · #40

Originally posted by SamDoe1:

If that's the case then he shouldn't worry. The preflash and main flash are so close together that you'd hardly be able to tell that there was a difference.

this is off topic, but i know for a fact that the preflash can scare away an insect BEFORE the main flash goes off

... thought i was go crazy that day

anyway ... at this point I just want to know WHY the camera does that ... I'm not interested in a work around (at the moment anyway)

Canon EF 24-70mm f/2.8L USM

01/09/2008 12:18:43 AM · #41

Originally posted by hopper:

at this point I just want to know WHY the camera does that

I will read my manuals tonight before bed and see if I can come up with any technical explaination.

dwterry

Canon EOS-1D Mark III

01/09/2008 07:19:21 AM · #42

Interesting... the 5D with the brand new 580EXII flash does the same thing:

AV mode + ETTL = normal behavior (shutter speed set to give ambient light exposure)
AV mode + Manual Flash = 1/200 shutter.
AV mode + Manual Flash in High Speed Synch = 1/8000 shutter

For the 20D the behavior is similar (changing only the sync speed):

AV mode + ETTL = normal behavior (shutter speed set to give ambient light exposure)
AV mode + Manual Flash = 1/250 shutter.
AV mode + Manual Flash in High Speed Synch = 1/8000 shutter

However, the 1D Mark III with 580EXII is different. No matter what setting I have on the flash, the camera picks a shutter speed that would expose correctly for ambient light.

So ... at this point, I think we can blame the DIGIC II chip in the 350D, 20D, and 5D cameras.

01/09/2008 07:45:38 AM · #43

same behaviour on a 1DII.

Av mode, 580EX on manual, normal sync,

forces shutter to 1/250sec

In high speed sync mode, holds shutter at 1/8000 sec.

Notionally if you are shooting with flash as the sole light, then the shutter speed is largely irrelevant
assuming you don't violate the sync speeds, so this seems something like a studio set-up sort of mode.

I'm not entirely sure of the use case you are really wanting though - it sounds like you want
subtle fill from the flash with no pre-flash. Doesn't that happen in ttl mode, if you dial
the flash down to say an EV of -1.7 (which is how I normally try to use fill outdoors)

I don't see a pre-flash unless I specifically trigger it with FEL.

01/09/2008 07:57:13 AM · #44

Dial it down in camera, or on the flash itself?

probably doesn't matter ... I'll give it a try

Originally posted by Gordon:

it sounds like you want
subtle fill from the flash with no pre-flash. Doesn't that happen in ttl mode, if you dial
the flash down to say an EV of -1.7 (which is how I normally try to use fill outdoors)

I don't see a pre-flash unless I specifically trigger it with FEL.

01/09/2008 08:31:03 AM · #45

Originally posted by hopper:

Dial it down in camera, or on the flash itself?

probably doesn't matter ... I'll give it a try

I expect it doesn't matter. I usually dial it down on the camera body.

Mr_Pants

SiPix Blink

01/09/2008 08:42:51 AM · #46

Originally posted by Gordon:

I don't see a pre-flash unless I specifically trigger it with FEL.

The camera will still do the pre-flash, though, and at the same intensity as at any other FEC setting. Quite often, one sees a flash through the viewfinder (which is the pre-flash) and mistakes it for the main flash, which is not visible through the viewfinder, as the mirror is already up.

If one's using fill outside, there is probably so much light about anyway that the pre-flash is not visible to the photographer anyway.

01/09/2008 09:53:39 AM · #47

Originally posted by Mr_Pants:

Originally posted by Gordon:

I don't see a pre-flash unless I specifically trigger it with FEL.

The camera will still do the pre-flash, though, and at the same intensity as at any other FEC setting. Quite often, one sees a flash through the viewfinder (which is the pre-flash) and mistakes it for the main flash, which is not visible through the viewfinder, as the mirror is already up.

If one's using fill outside, there is probably so much light about anyway that the pre-flash is not visible to the photographer anyway.

Yeah, I believe you - I just mean I don't see the pre-flash, even indoors under normal daylight conditions. I do see it through the lens as you describe, but I don't see it if I just take a picture looking at the camera/ flash.

From photonotes.org
First, the E-TTL preflash occurs immediately before the shutter opens and not when the shutter release is pressed halfway. Unlike the A-TTL preflash, therefore, the E-TTL preflash is actually used to determine flash exposure and isnâ��t fired during the ambient (existing) metering stage. Some users may be surprised to learn that E-TTL actually fires a prefire flash before the main flash at all. Using regular settings the process happens so quickly that the preflash is difficult to notice, though you might catch glimpse of it before the mirror blackout - an exception being second-curtain sync.

01/09/2008 10:01:19 AM · #48

Originally posted by hopper:

//photonotes.org/articles/eos-flash/index3.html

So I guess it's doing what it's designed to do. Complete mystery to me why it would do that.

Well - you are in aperture priority mode. You've said 'I'm doing the flash power control myself' by putting the flash in manual mode. That tends to imply that all the lighting is going to be flash lighting. At that point, the shutter speed is irrelevant.

If you are wanting to mix flash and ambient and you want to set the flash power yourself, you'd probably need to set the ambient exposure yourself too - i.e., in Manual exposure mode.

01/09/2008 10:07:45 AM · #49

When I started this threat, I didn't think I was trying to do something that had never been done before :)

Av mode so the camera will auto expose for ambient

tiny bit of flash, no preflash, ability to fire off a few shots before the flash needs to recycle

seems like a commonly done thing. The flash on the paparazzi cameras go off like machine guns .. they must be in manual exposure mode (and of course aren't using the 430ex)

Originally posted by Gordon:

Originally posted by hopper:

//photonotes.org/articles/eos-flash/index3.html

So I guess it's doing what it's designed to do. Complete mystery to me why it would do that.

Well - you are in aperture priority mode. You've said 'I'm doing the flash power control myself' by putting the flash in manual mode. That tends to imply that all the lighting is going to be flash lighting. At that point, the shutter speed is irrelevant.

If you are wanting to mix flash and ambient and you want to set the flash power yourself, you'd probably need to set the ambient exposure yourself too - i.e., in Manual exposure mode.