New User ST-E3-RT with 430EXIII-RT Display Setting Differences

[giles45shop]

I just purchased an ST-3-RT to use with my 430EXiii RT so I can do some off-camera flash work in the field for my herpetology hobby with my R5.  I am using only one flash and I am typically shooting in manual mode.  I was able to get the two synced up wirelessly on channel 1 with the ST3 as the master and the 430 as the slave.  I am able to adjust the flash power on the ST-3, and trigger the 430 remotely, but when I look at the display on the 430, the power displayed is not the same as what is shown on the ST-3 display.  Does the power setting on the ST-3 over ride what is shown on the 430 display? 

I already figured out that the ST-3 can't adjust the zoom setting on the 430 and that this has to be done on the flash itself, so that was confusing me  a little as to which display was showing the correct power setting?

[giles45shop]

I think I just figured out my own question.  When I initially set the power level on the ST-3, the 430 still displays the power level it was at prior to the latest ST-3 adjustment.  As soon as I pushed the test button on the ST3, it triggers the 430 flash and the 430 display now matches the same power displayed on the ST-3.

I guess a follow-up question is whether I need to push the test flash before I take an actual photo or whether just depressing the shutter button w/o first pushing the test button will send the right power to the 430?

Apologize if these are basic questions, but I am a relatively new photographer and still learning all the settings on my new toys 🙂

[p4pictures]

You are not asking basic questions at all... so keep tapping into the knowledge of the community members.

Canon sends the desired power level from a transmitter to the receiving flash;

1. Test button is pressed
2. The shutter is pressed to take the photo

The reason for this, is that if multiple cameras / photographers are used to control the same lights, then it needs to be the camera actually taking the photo that sets the power. 

Do you know if you have the ST-E3-RT version 2, or version 3 transmitter? The reason for asking is that these allow you to manually set lower power levels in manual mode. The original ST-E3-RT could only set the power level down the 1/128 in manual mode, but with the v2 and v3 units you can set down to 1/8192 power. Interestingly while your Speedlite 430EX III-RT cannot display less than 1/128 power, it will actually respond correctly to lower power settings from the v2/V3 ST-E3-RT transmitter - I know I tested it with a flash meter. This can sometimes be handy for macro work with more open apertures. 

Additional info; I've used the Canon radio flash system since its introduction in 2012, and have several transmitters and Speedlites. I would advise you to change the default ID of your transmitter and unit away from the 0000 that they are factory set with. You only need to do this once, but it will avoid conflicts with any other photographers who just happen to have a Canon transmitter and it's set to channel 1 and ID 0000. I've run many flash workshops over the years and almost everyone who turns up has their gear set on those defaults.