Flash coverage on a D60

[john20]

I have a Canon D60 and a 420EX. Ever since I started using the

flash, I have always wondered why the camera sets the flash coverage

at the focal length of the lens. This is actually diminishing the

power available to me from the flash. Here is an example: I mount a

20mm lens which is efectively a 32mm on my camera. Yet the flash

stays at the widest setting (24mm). Even if it would move to 28mm

would be of some help. The same goes for my 28mm(which is equivelent

to 44mm). The flash should move up to 35mm to be more effective. Is

it just me thinking of this, or is this something that Canon has just

overlooked? And is it something that Canon can fix with Firmware?

 

John

[steve_dunn2]

<p>If that's the way it works (I don't have a D60 so I can't say from personal experience), then your thoughts are correct. The camera should be designed to tell the flash to zoom to the focal length that, on a 35mm camera, would provide the same coverage, in order to give you the full benefit of a zooming flash head. APS SLRs should follow a similar procedure - if anyone has one and a zooming flash, can you tell us how this combo behaves?</p>

 

<p>This would be controlled by the camera's firmware, so if Canon decided it was worth fixing, a firmware upgrade would be the way to do it.</p>

[anov]

My EOS IX-E behaves the same way with both my previous 380EX and current 420EX. That IX is released in 1996 so they have overlooked this shortcoming for a while, so some power of the flash got wasted. It would be nice if they can fix this, but the APS conversion factor of approx. 1.3x it's not that big a deal for me.

[geoff_doane]

The IX APS camera and 380EX flash work the same way. It appears that there's a bug in the program which someone overlooked. It's no great loss with APS (not too many cameras out there), but with all the D30s, D60s, and more less-than-full-frame DSLRs yet to come, it would be nice for Canon to address the problem.

 

It seems that the lens will communicate its focal length to the camera, but whether that information is passed directly to the flash, or massaged by the camera software first, I don't know.

[john20]

Here is a question to tag on. Is it possible that the underexposure problems that I, and many other D60 owners have been experiencing, is a result of this? If someone out there with a D60 and a 550EX could try taking a couple of samples, one with the camera settings, and one with the flash manually zoomed, we may be able to get an answer on that.

 

John

[steve_dunn2]

<p>It won't cause underexposure unless you're exceeding the range of the flash unit at whatever zoom position it's set to. Remember that E-TTL metering is done by firing a preflash. The preflash is also affected by the zoom position, and since the zoom position for the preflash is the same as the zoom position for the main flash, the metering is consistent.</p>

 

<p>All this little oversight does is reduce the flash range.</p>

[yakim_peled1]

I think that the answer is much simpler. The camera knows that there is a 20mm lens mounted and sends these signals to the flash. The flash has no 20mm setting so the best it can do is 24mm.

 

It seems to me that the camera simply does not take into account the different sensor size, just the focal length of the lens.

 

To overcome this you should buy the 550EX. Only then you can set the focal length of the flash manually.

[gil_batzri]

It seems to me. Judging from what my camera (D30) reports as far as the extended data and other "impressions" that the camera firmware is not "aware" of the Focal Multiplier. It thinks it is shooting a 300mm shot when using a 300mm lens. The firmware is not that well designed unfortunately. I may give the manual/auto with my 550EX a try, but I wouldn't hold my breath on my doing it. I think if they built in compensation for it, the numbers reported would be modified and secondly, I think Canon would crow about it in their documentation.

 

Gil