Ask about manual Zoom.

I bought 430EXII, so I confused about auto zoom and manual zoom. For example: If I used lens kit 18-55, which is distance can I set for it?

You should select "auto zoom" and leave it there.

Auto Zoom on the 430EX II means the flash head will adjust so as to maximize the light for the Field Of View of the focal length you select on your lens.

Put the flash in "auto zoom" and move the lens zoom ring. You will see and hear the flash head moving back and forth in the flash.

Yep, I see. But the maximum zoom is 135mm. What happend when I use the zoom lens bigger 135mm? What happend if I set manual zoom 50mm when i use 18-55?

The max zoom available on the 430EX II is 105mm.

The only reason to use manual zoom (105mm) is if you want to be creative and only light the center part of the scene. At the other extreme (24mm), you will just waste flash power lighting up more than the lens can see.

If you set the flash to "manual 50mm", and your lens at 18mm, only the center of the scene will be illuminated properly. With your lens set to 55mm, you will have full coverage, but you will be wasting a little of the flash power.

In auto zoom, the 430 EX II will also take into account whether or not you have a crop camera.

If you use a longer lens, some of the flash power will be wasted. There is no way around this other than buying a flash modifier like a "Better Beamer" or some other device to narrow the flash beam.

philubonmat wrote in post #7411121
Yep, I see. But the maximum zoom is 135mm. What happend when I use the zoom lens bigger 135mm? What happend if I set manual zoom 50mm when i use 18-55?

LOL! Try it and tell us what happens.

One more thing.....

While in "Auto Zoom", if you angle the head up to use "bounce flash", the head will automatically default to 50mm for the best coverage.

Bounce flash is one other time when manual zoom might be handy, but 50mm seems to be a good compromise. By leaving it in auto, you lesson the chance of screwing up a straight ahead shot with the wrong flash head coverage.

40Dude6aedyk wrote in post #7411237
LOL! Try it and tell us what happens.

I mean, I confused between auto zoom and manual zoom. I don't know how to set distance in manual zoom mode. And I have given an example: If i set 50mm for manual zoom when i use 18-55 lens, what's happend with my picture? It's good or bad?

It will depend on what focal length you have your 18-55mm lens set to.

If you have it at 18mm, it will be bad. If you have it at 55mm it will be OK.

Your mean. If I use manual zoom, i must be set distance for flash for every position in my lens?

Phil,

The flash zoom setting simply changes the flash unit's coverage angle. It has nothing to do with distance (though it does affect the flash units maximum range). Zooming simply makes most efficient use of the light by covering an angle just large enough for your lens' field of view.

Here is what I suggest. Point your camera at a blank wall from 10 feet away. Zoom your lens to 18mm. Now manually zoom the flash to 105mm and see if you notice anything weird in the image.

Otherwise, just use autozoom as Mike suggested.

philubonmat wrote in post #7411598
I mean, I confused between auto zoom and manual zoom. I don't know how to set distance in manual zoom mode. And I have given an example: If i set 50mm for manual zoom when i use 18-55 lens, what's happend with my picture? It's good or bad?

Seriously, why can't you go try that yourself and tell us whether the picture is good or bad? Good or bad is so subjective and personal that you should be able to experiment and see what you like for yourself. I can understand that if you had to go to the dark room and develop film to see the results that it would be a pain, but with a digital camera it will take you less time to do the test shots than to read this message. And you will learn quite a lot by doing your own experiments ... I hope.

Also note that if you tilt your flash head upwards, that the zoom of the flash head will change if it is in auto-zoom mode.

Curtis N wrote in post #7411749
Phil,

The flash zoom setting simply changes the flash unit's coverage angle. It has nothing to do with distance (though it does affect the flash units maximum range). Zooming simply makes most efficient use of the light by covering an angle just large enough for your lens' field of view.

This is my purpose. Because I don't know the effect of unit "mm" in flash, i think it's the distance can use of flash to subject.
Thanks all! I approciated all answers!!!

The "mm" on your flash refers to the length of the lens you are using.

In the "Good Old Days" the flash head only had one position. Today it can "zoom" to try and match the viewing angle of the lens you are using.

You have a 18-55mm zoom lens. The flash has an adjustable flash head that will try to match the flash light coverage to the lens that you are using. So if you have the lens set to 18mm you should either use the flash's "auto zoom" function, or set the flash head manually to as close to 18mm as possible.

It has nothing to do with the distance of your camera/flash to the subject you are shooting.

Thanks so much msowsun!!! I got many lesson from this topic.

You are welcome. I hope you got it now.

And I hope you just use "auto zoom" like the rest of us...