hoppinghippo said:
Thanx clive, that's a very good point about flash lighting up foreground subjects only. So in a way all I should do is meter the background, estimate how much the foreground subjects are underexposed if I shoot at the background exposure and adjust my flash accordingly? but exactly how do you translate this difference in exposure to the flash compensation? eg. if my background is such that my foreground subject is 1 stop under the background metering and I wish to bump up the foreground subject, I need to provide enuff flash of +1 stop. so how do I adjust my flash? set it as full power then adjust -ve stops compensation? (if so by how much?) or set the flash as auto fill in (on camera body) and assuming flash will overexpose the foreground, dial in -ve stops on flash (if so how much?)?
Hi Hippo,
I'm using the same camera as u and I still have yet to get a consistent hang of it. But I'll try to help with the little I know. There is a very long thread on this in the Minolta forum and I'm just rehashing what was discussed there as succinctly as I can. FYI, the starter of that thread was ME!
But first I must make clear that I'm using a Minolta 5600 Program Flash with the useful LCD panel which tells me flash coverage distance. If u du have this it might be a bit hard to see the effects I mention. THe 5400 also has the same data panel.
Anyway from what I know, the camera behaves differently (based on its auto exposure modes -P, A and S) when u shoot under different lighting conditions.
If u shoot under bright light with flash, both flash and exposure compensation behaves normally as u would expect it to. For example, if u shoot on A mode and u get 1/250 at f/5.6 on ISO100. If u dial in exposure compensation, then the shutter speed will alter according to the number of stops u dial in. So if u dial in +1 stop exposure compensation, the shutter speed will drop to 1/125 to expose the background by 1 stop. And when u dial in flash compensation, the flash pulse will fire for a longer or shorter duration depending on how much compensation u dial in. So if u dial in +1 stop flash compensation, the flash will overexpose the subject by 1 stop. So as far as I know, under bright shooting condition, the exposure compensation dial compensates for the background (it does not affect the subject exposure cos u have a TTL flash which will fire to expose the subject properly within the limits of the flash range and power). And on the other hand, the flash compensation affects the subject exposure almost exclusively. Well, this is the easy part.
However, if u are shooting under low light conditions, again if on A mode, u get 1/60 at f/5.6 on ISO400. Now the camera limits the shutter speed to 1/60 regardless of how much exposure or flash compensation u dial in.
So let's say u are on TTL flash mode and A mode on the camera and u meter a scene and get 1/60 at f/5.6. On the 5600 flash, u get a flash coverage range of 1.5m to 10.0 m. If u dial in +1 exposure compensation, by right, one would expect the shutter speed to drop. But on the Dynax & (and I think all Minolta SLRs), it does not. What the exposure compensation does is to shorten the flash range. I'll find that your flash coverage range drops to 1.5 to 7.0m. The same occurs if u try the same with flash exposure compensation. Dialling in +1 EV for the flash also drops the flash coverage range to 1.5 to 7.0m. The reason is that the camera is programmed (according to what I learnt from other Minolta users here) to keep the minimum shutter speed to 1/60 to prevent camera shake.
Okay, that settles the way flash and exposure compensation works on the Dynax 7.
For the part about overexposed (white-out) faces in a low light shot, I also get that problem in the beginning. It's begin to go away now but still can be a problem when I forget some of the pointers from the bros in this forum.
The flashes we use (Minolta program flashes) are all TTL, so they should expose properly the faces. The TTL system works by metering the scene and determining which is the subject and deciding how long to fire the flash to properly expose the subject. This is read from the reflected flash pulse off the subject's face. Sometimes this system cocks up due to a variety of reasons but on the whole it works pretty well for me so far bearing in mind some pointers.
1) The flash pulse has a certain minimum timing. If u are too close to the subject (as when u use wideangle and move in close), the distance between the subject and lens is too short for the flash to cut off the flash pulse in time so u get an overexposed subject.
2) Make sure your subject is inside the flash coverage range. It seems that being somewhere in the middle of that range reduces the white-out look significantly. This prevents underexposure of the subject as well cos if u are outside the flash range, the subject will not be lit up properly.
3) Try to make sure that the subject fills up at least 1/3 of the frame. Cos if that is not the case, the camera will think that the dark background is the subject and then fire the flash at full power and try to expose the dark background properly and in the process severely overexpose the subject which is much brighter (and more reflective) than the background. I usually ensure that one of the focus sensors are placed on the subject's face as the TTL metering system seems to be tied in with the focus sensors. (Apparently this helps the camera to decide where the subject is in the frame).
4) U can use a bounce card, or bounce the flash off a ceiling or wall to reduce the hotspots on your subject's face. It diffuses the light so that it creates a softer, more natural look. Bouncing is tricky and I prefer a bounce card. But these two methods eat up a lot of battery juice cos the flash will probably be firing at full power all the time to expose the subject properly.
5) Shoot on M mode. From the old birds here - set aperture to what u want (shallow preferably f/5.6) and then set shutter speed at 1/30. Set the flash to TTL mode. Make sure u hold the camera steady and fire away. The 1/30 shutter setting will take care of the background details (most of it anyway) while the TTL flash will take care of the subject's exposure. Anything slower, u need a tripod.
6) If all else fails, use the P mode. Full auto or semi-auto P. It works wonderfully.
To Hippo, if u've seen all these before, sorry for the crap but if not, I hope this helps.
To the rest, please feel free to correct any misconceptions in my post. I still got a heck lot to learn about flash photography. :embrass: Thanks and cheers!