What does the AD-E1 actually do?

neuroanatomist said:

I was using One Shot. Tried Servo, as you say no AF assist but still a proper flash exposure.

I should also note that it’s certainly possible to use settings where the flash cannot provide enough power. For example, setting 1/8000 s, f/11, ISO 100 resulted in a barely lit exposure. But 1/8000, f/11, ISO 6400 was properly exposed with flash.

Click to expand...

That is possible too @neuroanatomist Flash photography can't fix every lighting problem. My friend who owns the both the R6 Mark II & R5 tried the same tests as you did. She ended up with correctly exposed pictures with flash. But I let her borrow my 600EX II-RT and she used her own AD-E1 hot shoe adapter on the R6 Mark II. But she used the variable aperture RF 24-105mm F/4-7.1 IS STM lens for this test. On both cameras the speedlite fired the AF Assist Beam. On a whim we tried other Canon speedlites new and old. She used her own 550EX, 580EX II, 600EX-RT and EL-1. Then my own 600EX II & 470EX-AI without any problems. We also reset ALL of the speedlites back to factory default. To make sure that an incorrect setting isn't to blame. The 600EX, 600EX-RT & 600EX II-RT also have light distribution settings too. I double checked the manual for this too. I think the 550EX, 580EX, 580EX II & EL-1 offer these settings too. I don't think the 400 series ie 430EX, II, III, III-RT or 470EX-AI, 300 series ie 380EX & 320EX or 200 series ie 220EX, 270EX & 270EX II.

deebatman316 said:

That is possible too @neuroanatomist Flash photography can't fix every lighting problem.

Click to expand...

More power could solve that problem. A 1/8000 s f/11 exposure at a low ISO is too much for a Speedlite, but possible with an HSS-capable monolight.

deebatman316 said:

My friend who owns the both the R6 Mark II & R5 tried the same tests as you did. … On both cameras the speedlite fired the AF Assist Beam.

Click to expand...

Camera matters there, too. The low light AF sensitivity of the R3 is 1-stop better than the R6II and 1.5-stops better than the R5.

For one of my R3 test shots with the RF 100-400 at wide end (f/5.6 max) the camera used the onboard AF assist lamp, not the Speedlite. I think that was at ISO 6400 but I’m not certain (was handholding and pointing the camera at the same scene, so I can’t say for sure that selected ISO matters for AF assist method, but I could test that hypothesis, I suppose).

neuroanatomist said:

More power could solve that problem. A 1/8000 s f/11 exposure at a low ISO is too much for a Speedlite, but possible with an HSS-capable monolight.


Camera matters there, too. The low light AF sensitivity of the R3 is 1-stop better than the R6II and 1.5-stops better than the R5.

For one of my R3 test shots with the RF 100-400 at wide end (f/5.6 max) the camera used the onboard AF assist lamp, not the Speedlite. I think that was at ISO 6400 but I’m not certain (was handholding and pointing the camera at the same scene, so I can’t say for sure that selected ISO matters for AF assist method, but I could test that hypothesis, I suppose).

Click to expand...

The manual says AF Assist Beam emission method is dependent on the ambient lighting. When my friend was testing the speedlite with the RF 24-105mm STM lens. The camera tried emitting the body lamp first. When it couldn't lock focus the camera sent the AF Assist Beam signal to the speedlite instead. Cameras released from 2007 ownward support the speedlite control menu. These cameras also allow the use of Intermittent Flash Firing or an LED AF Assist Beam. Now I'm not sure if these cameras can vary the voltage to the speedlite to provide a brighter pre-fire/ pre-flash for the AF Assist Beam. In dimly lit situations the speedlite would emit less pre-flashing and it also looks dimmer. But once we went into a darkroom the speedlite would emit brighter pre-flashing and it was more frequent. Pre-2007 cameras only support the IR AF Assist Beam. If you try using a speedlite set to Intermittent Flash Firing on these cameras the speedlite WILL NOT emit an AF Assist Beam at all. Speedlites equipped with a personal function for both IR & Intermittent Flash Firing also add a special feature for an R series camera. If the speedlite is set to Intermittent Flash Firing and a color filter or a flash diffuser is attached to the speedlite. The camera will emit the AF Assist Beam instead of the speedlite. Since Intermittent Flash Firing is disabled with a color filter or a diffuser attached. Also when these speedlites are set to IR the AF Assist Beam will emitted by Intermittent Flash Firing. When used on an EOS R series camera. Intermittent Flash Firing is NOT compatible on EOS M series cameras. The 320EX is the ONLY speedlite that will provide and AF Assist Beam on an EOS M series camera via an LED lamp.

deebatman316 said:

The manual says AF Assist Beam emission method is dependent on the ambient lighting. When my friend was testing the speedlite with the RF 24-105mm STM lens. The camera tried emitting the body lamp first. When it couldn't lock focus the camera sent the AF Assist Beam signal to the speedlite instead.

Click to expand...

I would assume that sensor sensitivity also matters. The AF sensitivity spec is based on an f/1.2 lens (R3 -7.5 EV, R5 -6 EV, R6II -6.5 EV), but with a slower lens there is less light for the sensor. Thus the f/2 zoom pretty much always uses the camera lamp, whereas the f5.6-8 zoom may need the additional light from the flash, if available.

neuroanatomist said:

I would assume that sensor sensitivity also matters. The AF sensitivity spec is based on an f/1.2 lens (R3 -7.5 EV, R5 -6 EV, R6II -6.5 EV), but with a slower lens there is less light for the sensor. Thus the f/2 zoom pretty much always uses the camera lamp, whereas the f5.6-8 zoom may need the additional light from the flash, if available.

Click to expand...

I was surprised that the R6 MK II tried firing the body lamp first. When the camera decided that the body lamp was inadequate it sent the AF Assist Beam signal to the speedlite instead. I would've thought since it was dark in the room and the aperture at F/7.1 @ 105mm. That the speedlite would've fired the AF Assist Beam instead of using the body lamp first. Does your R3 try firing the body lamp first. Or does it go straight to the speedlite when its too dark.

deebatman316 said:

Does your R3 try firing the body lamp first. Or does it go straight to the speedlite when its too dark.

Click to expand...

I’ve never seen it try both. But I only rarely shoot in very dim light.

neuroanatomist said:

I’ve never seen it try both. But I only rarely shoot in very dim light.

Click to expand...

I asked my friend and she's never seen the body fire then it switch to the speedlite. She regularly shoots in low light for crime scene photography and she does part time wedding photography with her mom. My friend started out with the R6 and didn't like it. Then moved to the R5 & recently got the R6 II. She ended up giving the original R6 to her mom when the image sensor went out in her original 6D. Her mom has the original R6 and she's seen the camera switch between body lamp and speedlite. She has either donated or sold her old gear mainly lenses. Her mom ended up keeping her old 600EX-RT & 580EX Mark II and got an EL-1. Her daughter ended up with the 550EX. I ended up with her old EF 85mm F/1.8 USM, EF 50mm F/1.8 STM lens and the 470EX-AI speedlite. I already own the 600EX II-RT and that's enough for me. I mainly use on camera bounce flash no wireless off camera slave flashes. This all started as a hobby and still is for me.