Canon 50D shutter issue.

[Smokedaddy]

Hopefully, there are a few 50D users out there. I know Krebs used one. Not sure if Charles is still on the forum. I've never had this problem before with my 50D. I had my flash setup ready to go on my Nikon MM-11 setup. When I set the shutter to 400, 800, 1000, 1500, etc., and I half-press the remote button, it jumps to 250th of a second instead of what I had dialed in. Any clues?

-JW:

[rjlittlefield]

This sounds like proper behavior, unless you are attempting to use HSS (high speed sync) mode with a compatible flash.

With an ordinary non-HSS flash, the shutter speed has to be at least 1/250 second in order to expose the whole sensor at the same time.

--Rik

[Smokedaddy]

Thanks, Rik. It just shows how much I still don't know but have been doing fine for quite a few years now. I haven't used flash that much, so that's probably the problem. I was under the impression that when I over-exposed an image while using a flash setup, that I could increase the shutter speed until I arrived at the proper exposure. Not valid with a flash setup.

[rjlittlefield]

I was under the impression that when I over-exposed an image while using a flash setup, that I could increase the shutter speed until I arrived at the proper exposure. Not valid with a flash setup.

Valid, but only with an HSS flash setup.

To explain... Non-HSS flashes put out a single short pulse of light, during which time the entire sensor must be exposed at once. But HSS flashes can also put out a relatively long pulse of light, lasting more than 1/250 second with uniform brightness. Within the long pulse of the HSS flash, the sensor can be exposed incrementally via a gap between two shutter curtains, same as happens with short shutter speeds using continuous illumination.

--Rik

[JW]

I have been using Canon 50D's exclusively, glad to see there are more of us out there. I believe that the maximum flash sync-speed for this model is 1/250, so regardless if the shutter is set to a faster speed, the default will be 1/250. Not sure if MagicLatern can override this setting, worth a try and while a bit fiddly, will not damage your camera or built-in software.

[Smokedaddy]

I have been using Canon 50D's exclusively, glad to see there are more of us out there. I believe that the maximum flash sync-speed for this model is 1/250, so regardless if the shutter is set to a faster speed, the default will be 1/250. Not sure if MagicLatern can override this setting, worth a try and while a bit fiddly, will not damage your camera or built-in software.

Thanks for the input. All of my microscope and stereoscopes (Wild/Leica M400 and M420) setups use 50D's. I acquired several 50D's with less than 500 shutter clicks on them over the past few years as spares for nearly nothing. Believe it or not, I have never used MagicLatern.

-JW:

[Pau]

I have been using Canon 50D's exclusively, glad to see there are more of us out there. I believe that the maximum flash sync-speed for this model is 1/250, so regardless if the shutter is set to a faster speed, the default will be 1/250. Not sure if MagicLatern can override this setting, worth a try and while a bit fiddly, will not damage your camera or built-in software.

If the maximum flash sync-speed for a given camera is 1/250 it means that at faster speeds you only have a band of the sensor illuminated between the first and second curtain. This will produce partially illuminated images, pretty useless.

At this excellent high speed video you can easily visualize how a focal plane shutter works
https://www.youtube.com/watch?v=CmjeCchGRQo

[JW]

Smokedaddy - I too am always on the prowl for used 50D's, I recently snagged one that had less than 100 clicks! I probably have a lifetime supply of these camera bodies, but may end up giving them to the resident monsters (teenagers) for use in school projects.

Pau - since the camera body communicates with the flash unit, this is not an issue, flash always syncs at 1/250 shutter speed, since the flash duration is much shorter than 1/250. I also use second curtain sync, although really doesn't matter at 1/250 shutter exposure times.

[Pau]

Pau - since the camera body communicates with the flash unit, this is not an issue, flash always syncs at 1/250 shutter speed, since the flash duration is much shorter than 1/250. I also use second curtain sync, although really doesn't matter at 1/250 shutter exposure times.

Sure, this isn't an issue, I stated is as explanation of the camera behavior (like Rik did)

[RobertOToole]

I have been using Canon 50D's exclusively, glad to see there are more of us out there. I believe that the maximum flash sync-speed for this model is 1/250, so regardless if the shutter is set to a faster speed, the default will be 1/250. Not sure if MagicLatern can override this setting, worth a try and while a bit fiddly, will not damage your camera or built-in software.

Hi JW,

You can get around the 1/250th s. limit using an aftermarket trigger and flash, but the downside is the entire frame wont be lit evenly. There will be a dark, underexposed area (forgot if its top of bottom). Sometimes if you are cropping a lot, or underexposing ambient in daylight and the subject is in the center it wont matter but in practice it usually doesn't look very good.

Best,

Robert