Help with using Speedflash

[alessign]

Hi,

I am bit confused about using attached flash in photography. I have read one article about Speedflash somewhere, didn't save the web page and can not find it anymore. There wasn't informations about bouncing flash, fill flash but about understanding the light and how to do proper setting on your flash unit. How the flash basically works and affect the ambient light and what settings require what is waste or does not affect at all. I am shooting with nikon D300 + SB600 and still confused with the settings. If I am indoor doing shots from different angle and positions in the room - auto setting fail (over exposed, under exposed...no flash bracketing mode) Depth of field is not in control..madness. It's bit disturbing to take always 2-3 correcting pictures using manual mode - opportunity lost if you know what I mean.

Can someone help me (us) understanding flash guns, strength and density of flash light, ISO, ambient light, speed, sync atc ? I am asking because I haven't find any forum about it. Maybe I wasn't looking for it enough? Thank you for your time!

Best Regards

[kencaleno]

Originally Posted by alessign

Hi,

I am bit confused about using attached flash in photography. I have read one article about Speedflash somewhere, didn't save the web page and can not find it anymore. There wasn't informations about bouncing flash, fill flash but about understanding the light and how to do proper setting on your flash unit. How the flash basically works and affect the ambient light and what settings require what is waste or does not affect at all. I am shooting with nikon D300 + SB600 and still confused with the settings. If I am indoor doing shots from different angle and positions in the room - auto setting fail (over exposed, under exposed...no flash bracketing mode) Depth of field is not in control..madness. It's bit disturbing to take always 2-3 correcting pictures using manual mode - opportunity lost if you know what I mean.

Can someone help me (us) understanding flash guns, strength and density of flash light, ISO, ambient light, speed, sync atc ? I am asking because I haven't find any forum about it. Maybe I wasn't looking for it enough? Thank you for your time!

Best Regards

Here's my piece on using flash:

Flash basics

On-camera flash, (forget the built-in flash) using a hot-shoe-mounted flashgun, directed straight at the subject is very flat lighting, possibly the very worst of all. There are ways that we can modify the on-camera flash to control our lighting. We can diffuse the flash by means of clip-on plastic domes, (think non-coloured Tupperware-type pots that will fit over flash head),or we can bounce our flash from ceilings, walls, off of reflectors, etc.,.
Balancing the light between existing light and flash is quite simple- Just remember that Shutter-speed controls existing light and Aperture controls the flash effect. You set your camera’s mode to Av (aperture priority) selecting aperture to desired depth of field. (ie: for weddings F8 does the job) Get a reading from subject. Take note of these settings. Now select M (manual) mode and use the settings you got from Av mode. Fit your flash to hot shoe, use manual flash. Try first maximum sync speed (usually 1/250 sec or 1/500 sec), then come down from here just adjusting shutter speed, and checking on monitor, until ambient light looks right. As for power setting, I like to start at ¼ power, then I can go down two stops to 1/8 and 1/16 power, and up to ½ and full power. (My flashguns only span from full to 1/16 power) For interior shots use the same method: If ambient light reads 1/125 @ F4, you will need to set aperture to F4, and set shutter speed at 1/500(if this is your camera’s maximum sync speed, or 1/250 @ F5.6 if that is your maximum sync speed, and bounce off ceiling.

Adjust power of flash until it looks right in the monitor. This gives a ratio of 3:1 as a basic starting point. A big advantage, especially when photographing people, is to have the flash off-camera, so wherever you wander to get different angles, your lighting with remain constant. If flash is on camera, you would need to make adjustments each time you move out of the pre-set range of focus. Your flash can be triggered by radio transceivers (Pocket-wizards) or by means of pc cables. For wraparound, or cross- lighting, you could place your subject between the sun and your off -camera flash, using the sun as fill and your flash as the main, or key, light

Ideally, indoor images should not show that flash was used, so for this to take place, modification is required. I use a black computer mouse-mat, which forms a half snoot and is rubber banded to the underside of my flashgun when bouncing off of ceilings etc., this ensures no direct light lands on the subject. You can choose of course, to use automatic mode for flash-or TTL, (Through The Lens) I just prefer the manual mode.

Problems occur when using flash under fluorescent illumination, where you will get a severe green cast over your images-Solution is to use a gel (Window green) over the flash window, and a magenta filter( FL-D) over the lens. These filters will lose you one stop of light, but the lens filter alone will do the trick, if you aren’t using flash. Why this works is green over the flash window equalizes foreground and background color temperature, and the magenta on the lens absorbs the green from both sources to neutralize the image.

Most cameras will let you select front or rear curtain flash set-ups, (Front curtain flash fires as soon as the shutter opens, while Rear (or second) curtain flash fires just before shutter closes) and for most types of photography Front curtain will do the job, If the subject is on the move however, Rear, (Second) curtain flash is the way to go, the reason being that if you were to use front curtain flash on a moving subject, the movement defining blur, especially against a black, or at least a dark background, would appear in front, and not behind the subject, giving the impression that the subject is going backwards. On the other hand, if you were to use rear-(second) curtain flash for say a portrait, and you are trying to capture a certain mannerism, you would not want the flash to fire too late and miss the emotion.

If you shoot at a party or wedding reception, indoors at night using the auto or programme flash setting, which is usually either 1/250 or 1/500 second, you will end up with ultra black backgrounds, and not the scene you saw. That is because the flash fired too fast to record background detail. Solution: set camera to shutter priority or manual mode, and adjust speed to between 1/30 and 1/8 second-these are normal settings for fairly dark conditions, because of the actual flash speed,. blur won’t be a problem. This is Known as “Dragging the shutter”.

When using Dragging method keep flash set to auto or ttl, as, unless you are comfortable with doing this , you could complicate matters. If you only have a point and shoot camera, use the night setting-the camera will automatically set shutter speed to allow background detail to be captured, BUT, you will need a tripod/monopod etc, as for night mode shutter speeds are likely to be a lot slower than 1/8 second

Flash doesn’t reach as far as you like? Up the ISO! -“Twice the distance, four times the speed”. For instance: If your flash has a Guide number (GN) of 25(metres (80 ft), the best you can expect is a realistic distance reach of 20 metres (60 feet) at Iso 100,so at Iso 400 you will get a realistic reach of 120 feet (40 metres),and at 1600 Iso, a reach of 240 feet (theoretically),but noise will play its part at high Iso’s.

If you are using an automatic flashgun, that does not give you fill-in values, just double the iso you are using. Meter the scene, select an f-stop for the DOF you want,set auto flashgun aperture to same f-stop, and take your shot,this will give a 2:1 ratio-your fill will be 1 stop darker that the main subject.

Regards, Ken

[Revald]

Visit www.strobist.com. That blog has so much information about shooting with flash, that you have the next few weeks ruined

[MinnesotaGuy]

Wow, thanks for the tips. This is really good stuff for us new guys.

[Chip]

Flash does complicate things, doesn't it? I was in exactly the same boat as you about 6 months ago, and found this planet neil site very useful, expecially the 15 flash photography technique items listed on the right hand side of his home page.

Hope this helps, good luck and have fun!

[wiwtb]

GREAT tips on using the flash! Learned a lot there..thanks!

[alessign]

Great suggestions from all of you guys, thank you so much! Getting better now ;-) Thanks again!!!

[kirbinster]

Should make this a sticky so it is easy for lots of people to find.

[PnwGuy]

Kencaleno...just wanted to say thank you for the detailed post you did. I am doing my first paid wedding tomorrow and although I thought I understood flash etc, I felt totally lost and inadequate while taking practice shots at the rehearsal today.

The good news is that I went to scout the location and took a few shots, which made me realize my challenge, and the other good news is that I found your post. The church has very low lighting and there are a lot of people in the wedding party and I wasn't getting much distance from my flash. Backgrounds were dark. I guess I didn't realize that upping the ISO also increased the distance for the flash. Been so long since I first read about it, then haven't had to use my flash much other than for fill.

I'm still going to show up early and test again. Thanks so much!

[Got2BeTrue]

Im still learning my camera but I know I can sit still and watch the numbers changes if in a semi-manual mode. So how is it that you can stay on one setting at a wedding as you move around and take pictures. I would think you would have to adjust, test, check with every shot taken. What am i missing about manual mode. not sure how you can keep the setting set as you move around and the lighting changes on you subject and the scene.

thanks in advance for any advise/insight.