funk1196 wrote in post #5953649
I just got my 580 ex ii, and i thought i'd take it to the park to see what kind of fill flash i could get... only... i couldnt use the max aperture on my lens of 1.8 because the shutter speed could only be 1/200, they were way overexposed.
Does anyone have any tips for using the flash in daylight, but still achieving small depth of field (if possible).
The only way i could really get a proper exposure was to put it in P and let it do it's thing.
Also, will mounting a flash off camera have the same exact limitations? (1/200)... or might i need an even slower shutter speed?
And... last thing, when you're shooting with a speedlite, do you always try to set for iso 100, or is auto just fine?
Assuming you wanted to use a small aperture for maximizing DOF, your first issue is what is correct shutter speed. On a sunny day, the Sunny 16 rule might say f/16 1/100 with ISO 100 is the correct exposure. (Convenient that 1/100 is < max X sync speed.) OK so far, now onward to the next issue.
Second issue is FLASH POWER....For example, with a relatively weak flash (GN40) at f/16 it could only reach out to 2.5' and any farther it would have decreasingly effective ability to contribute to the photo! If you splurged on a 580EX, it has a guide number at (APS-C frame) 30mm coverage of about GN150, at f/16 it could only reach out to 9.4' and any farther it would have decreasingly effective ability to contribute to the photo.
If you upped the ISO to 400...
Assuming you wanted to use a small aperture for maximizing DOF, your first issue is what is correct shutter speed. On a sunny day, the Sunny 16 rule might say f/16 1/400 with ISO 400 is the correct exposure. (Convenient that 1/100 is < max X sync speed.) If you dropped the shutter speed to 1/200 you need to set f/22 instead
The second issue, flash power....For example, with a relatively weak flash (GN40) the ISO GN is 80, and at f/22 it could only reach out to 3.6' and any farther it would have decreasingly effective ability to contribute to the photo! If you had splurged on a 580EX, it has a guide number at (APS-C frame) 30mm coverage of about GN300, at f/22 it could only reach out to 13.6' and any farther it would have decreasingly effective ability to contribute to the photo.
To the later question of ND filter...that only serves to reduce the total light entering the lens, and does nothing to alter the relative intensity of ambient:flash at all.
