Couple of basic Minolta flash questions

[dave_yuhas]

If the camera (Maxxum 7) is set to f/8 in A-mode, does setting the

flash (5600 HS) compensation dial to +1 change the flash output to

f/5.6 or f/11? (My guess is the former). Flash is in TTL-mode.

 

Why does the flash range (as shown on the flash's display panel)

decrease when setting flash compensation to +1? If the flash is

putting out more light, shouldn't the range increase rather than

decrease? To put it another way, if the flash output is changed to

f/5.6, dividing the GN by 5.6 results in a bigger number (distance)

than does dividing by 8.

 

Thanks for any help in advance.

 

Dave

[tom_montemarano]

I'll try answering your second question.

 

The flash range on the flash LCD shows the maximum distance that the flash will give proper exposure. When you set the exp comp to +1, you are telling the camera that you want the flash to expose 1 stop more. Since the flash can't increase its power more than its maximum, it can only give more exposure with the same power at a shorter range.

 

Tom

[matt hedgecoe]

If you're trying to compare a flash in TTL mode with a fully manual flash, then setting +1 on the flash compensation dial would be equivalent to setting f11 on a manual flash - not f5.6 as you think. If you were to tell the flash that your aperture setting was wider than it actually was, the flash would put out less light (under-expose).

 

Regarding the flash range readout, we know that light levels fall off the further from the flash you get. If the amount of light required for a correct exposure is, for example, 5 metres from the flash, then the distance that there will be sufficient light to over-expose must be nearer the flash, not further away. Hence the reason for the reduction in effective range when you dial in + flash compensation.

[dave_yuhas]

>>If you're trying to compare a flash in TTL mode with a fully manual flash, then setting +1 on the flash compensation dial would be equivalent to setting f11 on a manual flash - not f5.6 as you think.<<

 

When I bounce the flash or use a diffuser, I routinely open the lens by one or two stops. Isn't doing that equivalent to a flash compensation of +1 or +2? In other words, can't I use + flash compensation instead of opening the lens, thereby gaining DOF?

 

Dave

[matt hedgecoe]

>When I bounce the flash or use a diffuser, I routinely open the lens by one or two stops. Isn't doing that equivalent to a flash compensation of +1 or +2? In other words, can't I use + flash compensation instead of opening the lens, thereby gaining DOF?

 

As you open the lens, the flash will lower its output level accordingly and the TTL metering will control the final flash level to ensure the exposure is spot on - In other words, no compensation effect. It is best to use the flash exposure dial to ensure the results you want.

 

The other way would be to turn TTL off, put the flash in Manual mode and then in conjunction with a flash meter, alter the power settings of the flash until you get the desired result. Obviously a more complicated route to take and it does rather defeat the object of buying a flash like the HS5600 in the first place!

[wyverndude]

You're using an automatic dedicated flash unit on a camera that reads TTL exposure. When you open the lens by one or two stops, the camera compensates for your adjustment and continues to give the correct exposure, by adjusting the flash output.

<P>It will do the same thing if you were to close down one or two stops too -within the range of the flash.

<P>The biggest question is: Why, with TTL exposure and a dedicated flash unit, are you opening the lens one or two stops?

<P>The system (your camera and flash) are designed to compensate for bounce flash, diffusers, filters on the lens, and any f:stop setting you might choose. Yes, bounce flash requires either more output from the flash, or a larger aperture; but in auto flash mode, the camera is doing that for you (by giving you more flash output) negating any need to adjust the aperture. If you set +1 flash compensation, you are overexposing. Probably not enough to cause a problem with print film, but you are definitely overexposing.

 

<P>The reason for flash compensation is if you are shooting a subject which is NOT, on the average, 18% gray. If you have a predominantly white subject, the camera will tend to underexpose it -THIS is the case in which you would want to use flash compensation.

<P>But note that if you are using a Maxxum (D) lens, the lens reports distance information to the camera, which allows the camera to regulate the flash exposure based on distance to the subject, rather than simply reading subject brightness.

<P>I don't know how well this actually works in practise, but it's safe to assume it works quite well; which almost eliminates any situation when you might need flash compensation.

[matt hedgecoe]

>>I don't know how well this actually works in practise, but it's safe to assume it works quite well; which almost eliminates any situation when you might need flash compensation.<<

 

Using the flash compensation to turn the output down a stop or two is very useful for creating a natural looking fill flash. I can't think of many situations in which you'd routinely want to up the flash output though.

[wyverndude]

The Maxxum 7 does fill flash automatically too. If you depress the AEL button in flash mode, it fires the flash as fill.

<P>

THAT one I've tried, and it works nicely! :)

[sonicstep]

Here is a similar discussion: <a href="http://www.dyxum.com/dforum/forum_posts.asp?TID=16206&PID=153611">5600 HS Anomaly</a>

[sonicstep]

Matt H: "Using the flash compensation to turn the output down a stop or two is very useful for creating a natural looking fill flash. I can't think of many situations in which you'd routinely want to up the flash output though." <p>

 

I have found +2 flash exposure compensation necessary to adequately illuminate subjects. I have particularly noticed this for interior locations where a subject is 5m or so away during the evening when the ambient light is provided by 60W incandescent filament lighting. If +2 compensation is not used the result is a subject that appears much underexposed.<p>

 

I have found that the 7D's inbuilt pop-up flash provides more accurate subject illumination than the 5600 HS (D) flash gun, since compensation is not necessary for the same situation. So for me the ADI feature doesn't work.