manual controls

[ichuan]

Ok after my last question about whether to use ETTL or manual I have been well advised to learn the manual settings on my 580ex and 430ex flash units.

The problem I now have is that ive been reading tips on how to set the power of the flash but they are talking about F stops. Excuse me for being thick but my camera has F stops and the flash has ratio settings.

What are they talking about the lens or the flash?

[scottbergerphoto]

You seem to be getting mixed up with the advice you are recieving. When you put your Canon flash in Manual Mode, you are not selecting f stops. You should be seeing 1, 1/2, 1/4, 1/8 and such. You will also see a distance scale on the back LCD, which will show you the distance range of the flash for the f stop set on the camera. Remember there is a relationship between flash power, distance and f stop(camera lens).
At ISO 100, Max. Distance= Guide Number of Flash / f stop of lens.

[Curtis N]

Back when flash units had only one manual power setting, the only way to adjust exposure was by changing the aperture (f/ stop) according to distance using the formula Scott provided. You still have that option, and the flash unit will do the math for you. If you put the flash in manual mode you should see the distance scale change as you change the aperture.

But with the 580EX and many other modern flash units, you also have the option to adjust the flash power. This allows you to set your aperture where you want for the desired depth-of-field, then set your flash power as needed.

[ichuan]

Thanks, where I was getting confused was an example from a book I have where the author is explaining 45 degree lighting where he states " I always set my key light to F8". I now understand that he means he sets his camera to F8 and then adjusts the light accordingly!

[ichuan]

Thanks Curtis, does that still apply while using the ST-E2?

I understand that if I want to tone down the flash units power to lower the ratio but what does the zoom do?

[scottbergerphoto]

Originally Posted by ichuan

Thanks, where I was getting confused was an example from a book I have where the author is explaining 45 degree lighting where he states " I always set my key light to F8". I now understand that he means he sets his camera to F8 and then adjusts the light accordingly!

What that means is that he is adjusting the power of his flash such that the taking aperture to set on the camera is f/8.

[scottbergerphoto]

Originally Posted by ichuan

Thanks Curtis, does that still apply while using the ST-E2?

I understand that if I want to tone down the flash units power to lower the ratio but what does the zoom do?

You are mixing up apples and oranges here.
The power of a single flash has nothing to do with ratios. That is a completely different situation. Ratios are used in ETTL-camera controlled flash, when you are using two or more flashes, such that you control how the amount of flash selected by the camera, is divided up between the two or three flash groups.

The zoom uses a fresnel lens to try to focus the light where you need it based on how far or near the lens is focused in or out. If you intentionally zoom out your flash to a distance less then what your lens is set at, the light will be more diffuse by the time it reaches your subject and therefore less intense. ETTL will try to compensate for that so the results will be unpredictable.

[ichuan]

Ok my head is hurting now!

Say for example I have set my speedlight to manual settings and is being triggerd with a ST-E2 how do I set the power that I want?

[scottbergerphoto]

Originally Posted by ichuan

Ok my head is hurting now!

Say for example I have set my speedlight to manual settings and is being triggerd with a ST-E2 how do I set the power that I want?

I don't own an STE2. I use a 580EX as Master. With a 580EX you set the power of a slave unit set to Wireless Manual Mode via the Ratios Menu, but you aren't really setting a ratio. You are setting the Manual Power via the Master. It can get really confusing. You are using the Ratios Menu on the Master, but because the slaves are set to Wireless Manual Mode, you are not setting ratios, you are setting Manual Power. Look in the STE2 Manual under "Wireless Manual"

[PacAce]

Originally Posted by ichuan

Ok my head is hurting now!

Say for example I have set my speedlight to manual settings and is being triggerd with a ST-E2 how do I set the power that I want?

What you need to do is either get a light meter or use your camera LCD and histogram to check the flash results but this is how you would go about setting the flash power output:

The easy method:

1. Set the flash to manual mode. Set the camera to manual mode and the shutter speed to max sync speed or lower. The aperture will be determined below.

2. If you have a light meter, set it to auto-reset mode and position it where the subject is or would be. Make sure your ISO and shutter speed are set the same as your camera.

3. FIre the flash, either by taking a picture or by pressing the Test button (only if you're using a meter) on the flash.

4. If you are using a meter, see what aperture the meter displays and set that on your camera. Go to Step 6.

5. If you are not using a meter, check the LCD and histogram to see how the image came out. If it's too bright or blown out, stop down the aperture some more. If it's too dark or black, open up the aperture some more. Go to Step 3 and try again.

6. You are now ready to take some pictures. You may need to tweak the aperture setting to fine tune the flash exposure.

The better method.

1. Set the flash to manual mode. Set the camera to manual mode, the shutter speed to max sync speed or lower, and set the aperture as is appropriate for your use.

2. If you have a light meter, set it to auto-reset mode and position it where the subject is or would be. Make sure your ISO and shutter speed are set the same as your camera.

3. FIre the flash, either by taking a picture or by pressing the Test button (only if you're using a meter) on the flash.

4. If you are using a meter, see what aperture the meter displays. If the number displayed is birger than the aperture number set on the camera, decrease the power of the flash. If it's already at 1/1, move the flash closer to the subject/meter. Go to Step 3.

If it's smaller, reduce the power output of the flash. For example, if the flash is set to 1/1, adjust it to 1/2 or 1/4. Then go to Step 3 and try again.

If the aperture displayed on the meter matches what's on your camera, you're all set. Take a picture or two to make sure by checking the LCD or the histogram. Go to Step 6.

5. If you are not using a meter, check the LCD and histogram to see how the image came out. If it's too bright or blown out, adjust the flash output to a lower power.

If it's too dark or black, increase the flash output power. If it's already at 1/1, move the flash closer to the subject. Go to Step 3 and try again.

6. You're flash is now set to give the proper exposure.

[PacAce]

Originally Posted by ichuan

Ok my head is hurting now!

Say for example I have set my speedlight to manual settings and is being triggerd with a ST-E2 how do I set the power that I want?

BTW, if you are using the ST-E2, you have to set the power level on the flash itself. You can't do it via the ST-E2 because it doesn't have manual control capability like a 580EX used as a master does.

[scottbergerphoto]

Originally Posted by PacAce

BTW, if you are using the ST-E2, you have to set the power level on the flash itself. You can't do it via the ST-E2 because it doesn't have manual control capability like a 580EX used as a master does.

Good to know. Thanks Leo.

[ichuan]

Ok thanks thats a big help, however im still a little confused as to the zoom aspect. Should it always be set to the focal lenth of the lens?

[PacAce]

Originally Posted by ichuan

Ok thanks thats a big help, however im still a little confused as to the zoom aspect. Should it always be set to the focal lenth of the lens?

The only time it would really be useful (to a degree since having it wider doesn't really hurt anything except to use up a tad bit more battery power than necessary) is if it's mounted on the camera and pointed directly ahead. But if it's set for bounce or used remotely, then you probably want the flash set for a wider zoom position to make sure that the flash covers the whole area covered by the lens. The default setting for the flash is to go wide when it is not mounted on the camera unless you override the zoom manually.

[ichuan]

Thanks again, you have all cleared up a lot of confusion that I had. I think now its a case of play around and trial and error to have a full understanding of what has been explained.