An open letter to Canon regarding the Canon RT system

[RLPhoto]

I'm planning to replace my 580 EXII's with 600RT's because the 580's optical system didn't do 2nd curtain anyway. If I'm in serious need for 2nd curtain for a off-camera flash shoot, I'd just take my strobes.

[AvTvM]

I expect the reason first curtain sync is the default is to avoid the issues of second curtain sync when photographing (still) people.  If ambient light is low (as it often is when needing flash), shutter speeds are longer, and there's a noticeable lag between the E-TTL preflash and the second-curtain flash - that often results in people blinking during the flash exposure, and a few people with closed eyes in a group photo.

yes, valid point. 

[Marsu42]

that often results in people blinking during the flash exposure, and a few people with closed eyes in a group photo.

Excellent point, can you specify from your experience (or anyone else) what the slowest shutter time is that is still very likely to prevent people from blinking before the exposure is done? Maybe 1/60s? Or even slower?

[Lawliet]

That depends on the camera - estimate about 1/10s for the blink reflex, that time has to accomodate the release lag and the exposure time. I.E. the extremly fast 1Dx with a wide open lens allows for longer second curtain exposures then its cousins with more muted mirror slaps and an aperture that takes its time to close. For me 1/15 works most of the time with the 1D/7D series. YMMV.

[Marsu42]

That depends on the camera - estimate about 1/10s for the blink reflex, that time has to accomodate the release lag and the exposure time. I.E. the extremly fast 1Dx with a wide open lens allows for longer second curtain exposures then its cousins with more muted mirror slaps and an aperture that takes its time to close. For me 1/15 works most of the time with the 1D/7D series. YMMV.

Thanks, but that raises some more questions (I really didn't think about this whole issue yet):

* Wouldn't a large open aperture mean a longer release lag than a small aperture that already is at the setting the shot will be taken with ... you're writing it the other way around?

* Is the aperture shutting much of a lag at all in comparison to the camera mirror lag?

* If the mirror speed has such an influence, why is the shutter lag on both the 5d3 and 6d 60ms? Or is this information (from http://www.the-digital-picture.com/Reviews/Canon-EOS-6D-Digital-SLR-Camera-Review.aspx) wrong?

[Lawliet]

I meant wide open as in set to its largest aperture - That 24-70IS set to f/4 or f/5.6 should be faster then the 50/1.2 set to 3.5. (assuming similar mechanics)

For the other points: the 1Dx has that CF that switches between constant shutter delay and fastest release. Which suggests there some kind of artificial regulation in effect; and the max difference indicates about 10-12ms(IIRC) for aperture actuation. About a quarter of that cameras overall release time.

[unfocused]

A good point for a pressing open letter would be to ask Canon how they can consider the 600rt flashes a *system* with just two parts available...no receivers for legacy speedlites or studio flashes...

I've been beat up by some on this forum for raising this in the past, but I still feel strongly about it. Canon released only half a product with its radio transmitter. Who releases a transmitter with no receiver? By doing so, Canon undercut it's loyal customers and sent them to competitors. I would have (reluctantly) paid a premium for a Canon-branded receiver to use with 580EXII and the ST-E3-RT along with the 600-RT.

Instead, they've driven me to the Yongnuo 622C (which is very good) and to the used market for future purchases of 580EXIIs. It was a shortsighted strategy on Canon's part.

[Marsu42]

It was a shortsighted strategy on Canon's part.

It's a well known problem long-term strategic benefits don't show in quarterly profit reports, and many shareholders are only interested in short-term stock profits.

But I agree what Canon is currently doing isn't very clever, they're risking even their recent "Canon is expensive, but best" image by releasing half-baked products like the 600rt flash "system" or the 6d camera. But the recent interview with their exec suggests they know by now they have to do innovate a bit more than just adding radio tech to the 580ex or re-releasing the 5d2 as the 6d...

[Area256]

I am very happy with both my 600-EX-RTs and the ST-E3-RT ... they deliver every single time without fail. I think Canon did a very good job ... Canon did not make any false claims about this product ... it delivers what Canon said it would.

As much as I don't like the lack of 2nd curtain sync, etc.  I think Canon did a reasonable job with the system.  They are, as far as I know, the only company to incorporate a radio transceiver into a flash. Which is saying something.  I'm kind of surprised no 3rd party manufacture, and no other camera manufacture has copied the system.  Not having to deal with separate radio transmitters would be awesome for quick setups (and to avoid having to charge extra sets of batteries).   

I don't really expect them to make the system comparable with older flashes or other brands, after all they want to sell as many 600EX-RTs as possible.  And I also fully expect them to hold out on the 440EX-RT as long as they can; after all they have no real competitor for this kind of integrated system yet  - and the market rules.

I'm currently on the edge between using the RT system for convenience, or going with Phottix to get second curtain sync and studio strobe compatibility...   I am disappointed they didn't put 2nd curtain sync in, since then I would have been sold on day one - but for most people I suspect it's a great product.

Having said that, I'm all for writing Canon to ask them to add these features.  It may do nothing, but at least it'll make them aware of the demand, and maybe the next generation of flashes will address those issues.

[brad goda]

Yes 2nd curtain and remote zoom control would be nice to have...
more so a battery level indicator would be very practical... or when ETTL flash was fired what power output from flash was used... longer operational range or the ability for add on antenna ... or RGB flash tubes that can be set for AWB or manual Kelvin and HUE...
and 200,400 or 800 w/s output... on and on..
I gotta say Canon moves forward to improve its products and they did a great job with the new EX system.  If you dont see what you need from the EX system now... wait a bit... they might add features...
personally the EX system is great... radio telemetry all built in. no need for radios dangling about.

ONE pet peeve I DID have was the controller COULD have had a tilting feature... while on the top of my ladder and the camera set high up I cant see the top of the controller.... so i used off camera cable to view.... DUH!!! I could have just used the cameras view finder on "off camera flash" setting... oh well... live,, make mistakes... and learn...