Topic: Canon screws with flash speeds (Read 12412 times)

janisr · « **on:** May 11, 2009, 01:48:23 pm »

Has anyone noticed, that Canon never reaches its specified flash speed?
I have had this problem with any canon i have had - 20d, 5d, 1ds MkII, and now with the 1 Ds Mk III !
The maximum usable sync speed when shooting with flash is 1/125, not the 1/250 as stated in camera specs!!!
See the sample below - shot outside with flash and maximum allowed sync. speed of 1/250 - notice the darkening on the lower part of the frame?

Have you ever had problems like this? is it my shutter, or Canon?

DarkPenguin · « **Reply #1 on:** May 11, 2009, 02:03:20 pm »

I haven't had any issue. But then I don't do a ton of flash.

I would suggest asking the strobist group on flickr. They're mostly off camera small strobes but there should be someone there who can answer.

http://www.flickr.com/groups/strobist/

JonRoemer · « **Reply #2 on:** May 11, 2009, 02:16:46 pm »

Quote from: janisr

Has anyone noticed, that Canon never reaches its specified flash speed?
I have had this problem with any canon i have had - 20d, 5d, 1ds MkII, and now with the 1 Ds Mk III !
The maximum usable sync speed when shooting with flash is 1/125, not the 1/250 as stated in camera specs!!!
See the sample below - shot outside with flash and maximum allowed sync. speed of 1/250 - notice the darkening on the lower part of the frame?

Have you ever had problems like this? is it my shutter, or Canon?

I've never seen that unless you are really in someone's face with a wide angle lens and the flash can't cover the area of the frame.

Was that shot with a Canon speedlite or something else? Canon doesn't guarantee the top sync speed when using studio strobes. Check the manual. It's in there.

julius0377 · « **Reply #3 on:** May 11, 2009, 02:30:05 pm »

I have noticed exactly the same with all my canons... but only when using studio strobes.

Quote from: janisr

Has anyone noticed, that Canon never reaches its specified flash speed?
I have had this problem with any canon i have had - 20d, 5d, 1ds MkII, and now with the 1 Ds Mk III !
The maximum usable sync speed when shooting with flash is 1/125, not the 1/250 as stated in camera specs!!!
See the sample below - shot outside with flash and maximum allowed sync. speed of 1/250 - notice the darkening on the lower part of the frame?

Have you ever had problems like this? is it my shutter, or Canon?

dwdallam · « **Reply #4 on:** May 11, 2009, 09:36:37 pm »

I'll bet you're shooting wireless, right? If so, the problem is that the wireless unit you're using can't synch faster. This is why I never wanted to go with the older pocket wizards--they only syched at 1/160th.

I had that problem with a cheapo wireless. It wouldn't sych any faster than 1/200 on a 20D I had. In the beginning it would, but for some reason, with use, it got slower.

I can confirm that both my 5D and 1DSMKIII do synch at their specified speeds using the new Alien Bees wireless flash units.

If wireless is your problem, try using a PC cord to confirm that, since the cord will have not have problems that a wireless might have.

Jonathan Wienke · « **Reply #5 on:** May 12, 2009, 10:13:49 am »

Quote from: janisr

Have you ever had problems like this? is it my shutter, or Canon?

Canon only guarantees the 1/250sync speed with their own Speedlites. According to the 1Ds and 1D-II manuals, the fastest guaranteed sync speed for strobes is 1/160, not 1/250, and if you are using cheap wireless flash triggers, maximum sync speed is reduced even further.

Ben Rubinstein · « **Reply #6 on:** May 12, 2009, 10:40:43 am »

Oh I don't know, my cheap chinese triggers will give me a comfortable 1/160 on my 5D's but the Elinchrom Skyport is said to only hit 1/125 on the same camera.

DarkPenguin · « **Reply #7 on:** May 12, 2009, 10:47:08 am »

Quote from: pom

Oh I don't know, my cheap chinese triggers will give me a comfortable 1/160 on my 5D's but the Elinchrom Skyport is said to only hit 1/125 on the same camera.

My cheap Chinese triggers are (mis)triggered by my flashes after about 5 minutes of use. Can I assume you are not using small canon strobes with them?

Ben Rubinstein · « **Reply #8 on:** May 12, 2009, 10:54:48 am »

There's probably a huge range of different cheap chinese radio sets! I have mine plugged into strobes. Never tried them with my 580's to date.

Gordon Buck · « **Reply #9 on:** May 12, 2009, 11:28:50 am »

My own Canon 20D, Cactus V2s cheap wireless triggers, Nikon SB-24 -->> 1/160 limit
My own Canon G9, Cactus V2s cheap wireless triggers, Nikon SB-24 --> 1/640 limit

Hoang · « **Reply #10 on:** May 12, 2009, 03:06:08 pm »

Quote from: gordonsbuck

My own Canon 20D, Cactus V2s cheap wireless triggers, Nikon SB-24 -->> 1/160 limit
My own Canon G9, Cactus V2s cheap wireless triggers, Nikon SB-24 --> 1/640 limit

My Canon 20D, Cactus V4 cheap wireless triggers, Alien Bees B800 ->> 1/250 limit
My Canon 20D, pc sync cable, Alien Bees B800 ->> 1/320 limit

sojournerphoto · « **Reply #11 on:** May 12, 2009, 06:11:58 pm »

My cheap triggers work at full sync on my 5D or 1Ds3 when they are feeling in a good mood - i.e. the 580 or 430 ex batteries are fresh (this is the most critical item). When the strobe batteries start to flatten they can't sync above about 1/125 or even 1/60. The strobes are always fine at max speed if mounted on camera or using the canon ir system.

There is an issue with the 430ex getting false triggers on some chinese sets. There are loads of alleged fixes, but I found that changing channels reduceed it to a very low (and acceotable given the cost) level

Mike

CaptainHook · « **Reply #12 on:** May 13, 2009, 03:31:32 am »

On my 5D with pocket wizards i got 1/200 with White lightnings fine.

Just got my Mark II today so am yet to test.

Jonathan Wienke · « **Reply #13 on:** May 13, 2009, 09:37:36 am »

Using Pocket Wizards and Alien Bees I can get 1/250 with my 1Ds and 1D-II.

Frodo · « **Reply #14 on:** May 13, 2009, 02:55:08 pm »

Quote from: janisr

Has anyone noticed, that Canon never reaches its specified flash speed?
I have had this problem with any canon i have had - 20d, 5d, 1ds MkII, and now with the 1 Ds Mk III !
The maximum usable sync speed when shooting with flash is 1/125, not the 1/250 as stated in camera specs!!!
See the sample below - shot outside with flash and maximum allowed sync. speed of 1/250 - notice the darkening on the lower part of the frame?

Have you ever had problems like this? is it my shutter, or Canon?

With respect, this looks more like flash falloff, rather than a synch problem. Synch problems are normally evidenced by a much sharper cutoff at the bottom of the frame as in the attachment. This was with a non-Canon flash on my 20D at 1/500. My 380EX synchs fine up to 1/250 with no falloff.

I think that your flash falloff is due to the flash not being aimed at the subject. It looks like an off-camera flash. Do a test by shooting at a wall, like I did.

Cheers

janisr · « **Reply #15 on:** May 14, 2009, 04:15:09 am »

This is no flash falloff,
here is a test shot with a broncolor ringflash - no falloff here - if I do a test shot, it looks even worse:
shot at 1/250 - which is supposed to be the top sync speed, the first usable with studio strobes is 1/125
with canon speedlites there are no problems - works fine with the high speed sync mode enabled.

janisr · « **Reply #16 on:** May 14, 2009, 04:20:26 am »

tried the cable - now I can use 1/160 or in some cases 1/200
thanks

Snook · « **Reply #17 on:** May 14, 2009, 09:16:40 am »

Quote from: janisr

tried the cable - now I can use 1/160 or in some cases 1/200
thanks

Watch out as it has been know that the shooting with the cable can fry your sensor.. Not sure if they changed that on the 5DII or 1DsMIII but I have heard stories.
You need the pocket Wizards MultiMaxes....
Snook

Jonathan Wienke · « **Reply #18 on:** May 14, 2009, 11:04:32 am »

Not the sensor, but the switch inside the camera that triggers the flash. Some cameras have a 6-volt limit before things go bad.

janisr · « **Reply #19 on:** May 14, 2009, 01:49:50 pm »

Quote from: Snook

Watch out as it has been know that the shooting with the cable can fry your sensor.. Not sure if they changed that on the 5DII or 1DsMIII but I have heard stories.
You need the pocket Wizards MultiMaxes....
Snook

I use the original transmitter, that came with the system -Broncolor RFS
but I still feel screwed - because outdoors there really is difference when shooting with 1/125 or 1/250
Any Nikons have the same issue?

Author Topic: Canon screws with flash speeds (Read 12412 times)

DarkPenguin

DarkPenguin

Snook