A2e autofocus obstruction

greenspun.com : LUSENET : Canon EOS FAQ forum : One Thread

The 70-200L blocks the AF beam. My 28-105 doesn't block it. I've heard that the A2e can't use external flash AF assist beams because of its AF horizontal sensitivity pattern. Before you go, "Now now silly boy, if you read the Helsinki archives then you would see that the camera disables ALL external AF assist beams" I would like to know if there is some hokey solution. I can't really experiment here but here goes... 430EZ with CF7 disabling AF 540EZ with CF7 disabling AF any of the above with center focus point used and CF7 I saw one thread where someone got it to work but he failed to explain how. Even though 2.8 is lightning quick, on low contrast it stinks pretty badly. I have even tried laser pointers and Maglite IR flashlite solutions. They are OK, but I look pretty stupid shining laser pointers at people. AND NO I DON'T TRY AF ON BLANK WALLS.

-- J Viray (manganous@aol.com), June 10, 1999

Answers

At the risk of sounding like I'm under estimating your problem, are you saying that when you use the 70-200L lens, that the flash in some way finds this as an obstruction. I can appreciate that an internal flash would, but not a 430EZ or a 540EZ. Could you expand or simplify your problem.....Regards

-- Garnet Cook (garnet_cook@one.net.au), September 26, 1999.

The problem is not that it is blocking the flash, but that it is blocking the AF assist beam. Because A2e was the first(?) EOS with five point focusing and the 430EZ did not support multi-point focusing, the AF assist on the camera was designed to override that of the flash. As far as I know there is no remedy to this problem.

-- Jim Simon (jsimon724@aol.com), October 03, 1999.

Jim (and others), I have searched EOS5/2A/E User Guides (both Hove and Magic Lantern) and cannot find any info regarding the above "over- ride" - Have I got it right? My suggestion to J Viray was going to be - Add a hot-shoe adaptor to lift the flash emitter a few centimeters and solve the problem physically. However, this would be useless if the flash emitter is disabled. QUESTIONS>>>...... Is this permanent over-ride on the EOS 5 as well?......Does this over-ride condition remain, when Eye Control AF is "off"?......Does this over-ride condition remain when Eye contol is "off" and focus is utilising (locked) centre position. ---- Regards.

-- Garnet Cook (garnet_cook@one.net.au), October 07, 1999.

As far as I know, on all versions (A2e,A2,5) the AF assist on the body disables that on the flash. You would have to go with a 1n in order for the AF assist on your 540EZ to work. Kinda sucks doesn't it?

-- Jim Simon (jsimon724@aol.com), October 07, 1999.

Eureka! I taped a miniature periscope to the emitter and then angled the mirror slightly down. It works fine, cant say the wide a-rea lines cover the points ALL the time, but when it counts, it does. I've ordered fiber optic cable to see what that would do.

Thanks for all your responses!

-- J. Viray (manganous@aol.com), October 08, 1999.



Moderation questions? read the FAQ