D300 + SB800, first steps.

Relentless

Hi there,

I'm making my first steps on inherited gear and I'm having some troubles with using the flash for my purposes.

My problem can be summarised by an example:

When being in a dark room, the correct matrix exposure settings (M mode) say 2" at f. 8 , when I take the photo (lamp set to TTL mode) it turns out ok. However when I decrease the time to 1/125, for example, it still is fine and I don't have to worry about shaky hands or my target moving.

The question is therefore: in case of shooting moving objects, how do I determine the correct exposure settings, or do I just have to accept the fact that the meter will always warn me about huge underexposure ?

Zerodog

It all depends on what other settings you are using. What mode are you in? What is your ISO? Exposure is a balance of shutter speed, aperture size, and ISO.

Relentless

The settings are: TTL BL mode, ISO 400 and focal length 105 ( setting on the lamp conforms to actual lens setting). Camera in Manual mode, rear synchro.

Zerodog

In TTL mode your flash is pretty much in AUTO mode. It will try to compensate and give you a proper exposure no matter what the settings on the camera are.

I hope this helps.

Relentless

I will try to explain it more clearly. When I am in a dark room, the correct parameters at ISO 100 are for example 1" at f 5.6. I put my camera to manual mode and select 1/125 to shoot moving object. Then the meter at the camera indicates large underexposure.

The question is: do I just have to ignore the camera warning me of the darkness and take the pictures and adjust from there (more background light or more direct coming from amp)?

ziggy53

I moved this to the Technique forum, where you'll find similar threads about ambient and flash exposure settings.

ziggy53

A few pertinent posts:

http://www.dgrin.com/showthread.php?t=116359
http://www.dgrin.com/showthread.php?t=214984
http://www.dgrin.com/showthread.php?t=214162
http://www.dgrin.com/showthread.php?t=212755

Qarik

okay so if you increase your shutter speed to capture a moving object and a darker room, since your flash is on TTL, it will *try* to compensate for the adjusted shutter speed..you don't have to do a thing. What I mean by *try* is the flash will output as much as it can but there may be limitations..if the room is very large or your are bouncing the flash or if you set your shutter speed way too fast then the flash may not be powerful enough to overcome these situations and may result in an underexposed image.

spinero

Flash exposure is not affected by the shutterspeed under 1/200 or 1/250 depending on your camera. So your flash output is the same all things being equal. If you camera is in shutterspeed priority mode, then it will open up the aperture to make the ambient brighter. Then your flash works less. Manual is the way to go on the camera if you are using flash. It is just much easier. Get your camera settings for the scene in automatic if you have to, then move those settings to manual and ride the flash compensation setting for the flash. If your background is too dark, you can slow down the shutterspeed quite a bit. The flash will stop motion.

Sam

Relentless

Thanks guys, I now moved to Manual setting on the camera and my starting point is 1/250 at f 5.6 (provided I require small depth of focus) and ISO 100 to 400 in darker situations. And ignore the EV indicator on the screen/viewer.

When I shoot moving objects with variable focal length I use the automatic TTL to get it right.
When I shoot stationary objects (repetitive shots possible) I use Manual setting on the lamp, start from 1/4th of power usually and adjust from there. Both the camera and lamp are in M modes.

EDIT: forgot to mention, when I want more background visible i go down to 1/60 or longer and use rear synchro to "freeze" the subject.

Does this approach seem reasonable?

ziggy53

Relentless wrote: »

Thanks guys, I now moved to Manual setting on the camera and my starting point is 1/250 at f 5.6 (provided I require small depth of focus) and ISO 100 to 400 in darker situations. And ignore the EV indicator on the screen/viewer.

When I shoot moving objects with variable focal length I use the automatic TTL to get it right.
When I shoot stationary objects (repetitive shots possible) I use Manual setting on the lamp, start from 1/4th of power usually and adjust from there. Both the camera and lamp are in M modes.

EDIT: forgot to mention, when I want more background visible i go down to 1/60 or longer and use rear synchro to "freeze" the subject.

Does this approach seem reasonable?

While these settings may not be optimal for "everything", I am impressed with your rapid grasp of the concepts. I encourage you to experiment more. Do remember that higher ISO often helps to "reveal" the background "and" it can reduce flash cycle times and/or increase flash range.

Experience will help guide you towards choosing the best combination of ambient and flash exposure settings for the given situation and subject, but you are well on your way.

Relentless

Thank you for your help Ziggy. now i have a bit bigger challenge coming up. It will be a rehearsal performance in a local concert hall, my friends will be on stage and i will be doing some shots. It is a dark room (obviously) with direct light shed on stage. I am planning to use the following:
SB800 with diffusion dome attached, working in remote at a side or behind me, directed upwards to bounce of walls and ceiling.
D300 with built in lamp switched on at manual + some kind of a contraption to diffuse the light going forwards
2 basic lenses ( no money for anything better I'm afraid) 28-100 + 55-200 VR will be used at all times.

The room is approx 15m across with the stage 5m deep, the audience part is 10m deep.

Any advice on lamp placement, diffusor use, bounce cards and stuff like that? I will probably run full power for SB800 and diffused TTL from the camera to get some light coming from the front line. I have never done this before, please excuse the long post.

ziggy53

Relentless wrote: »

Thank you for your help Ziggy. now i have a bit bigger challenge coming up. It will be a rehearsal performance in a local concert hall, my friends will be on stage and i will be doing some shots. It is a dark room (obviously) with direct light shed on stage. ...

If it's typical theatrical lighting you may need to filter the flash in order to match the white balance of the stage lights (probably best matched at tungsten.)

I suggest using your external flash as fill light, unless you need to stop action. If you do need to use the flash as the key light, and if you need to work at a distance, a flash modifier (diffuser) may reduce the output too much to be useful. Other than a filter to try to white balance the flash to the stage lighting, you may need to use direct flash.

If you do use the flash as key light, try to keep the stage lighting as a fairly strong fill light. A high ISO setting is generally indicated and necessary.