Sync Speed Indoors/Outdoors - Flash?

lifeinfocus

I am trying to get a handle on sync speed settings with one onboard flash. How to determine the sync speed depending on location (indoors/outdoors) and type and amount of light.

I do fully understand exposure triangle, so that is not an issue.

What I am trying to understand is why would I use a lower or higher sync speed outdoors or indoors. For indoors I suppose it is to reduce degree of other artificial light and for outdoors to include more natural light?

Given that, here are two examples where I could use your expertise and ideas:

1. Outoors - using one flash on camera, say 1/8 th power on flash, manual mode, ISO 400, f2.8 to add just a little light for portrait (fill light). Would the sync speed be at its highest level, which is 250 on my camera, or somethings less and why? I am sure there are other setting considerations, but this is intended to just get a rough idea.

2. Indoors - working on event in the evening where no outside light and indoor light is perhaps overhead fluorescent. using one flash on camera, say 1/8th power on flash, manual mode, lowest ISO possible, f2.8 to f5.6 for individual to small group photos. For instance, at a wedding after the dinner and people are dancing. Flash could be directly at subjects or bounced say off a rogue flash bender. Would the synce speed at its highest level, say 250, or less and is so why? I am sure there are other setting considerations, but this is intended to just get a rough idea.

And a side question, if you a diffuser like Rogue Flash Bender would the zoom setting on Nikon flash be set to wide, narrow, or middle?

Thanks for your consideration,

Phil

ziggy53

It's important to understand your goals for the image and how you intend to use the light available to you, namely the ambient/available light plus the incident/flash light. To some extent, indoors and outdoors don't matter as much as your intent for the shot.

If your ambient light is principal to the shot, and the flash is only intended to supply fill, that's a much different situation from the ambient light not mattering so much, and the flash supplying the primary light for the scene. Once you measure the ambient light, and you decide how you will use it, you use the shutter speed to help control the ratio between ambient and incident. (Up to the sync speed, only the ambient light is affected by shutter speed.)

In other words, without knowing your intent for the shot and without knowing the ambient light levels, it's not really practical to try to advise you on your two scenarios.

What I highly recommend is just dive in and do some serious testing in different situations, recording the settings for each situation and each result. You'll rapidly understand the relationships involved and the results you can predict.

I stress that measuring the ambient, along with designing the goals for the image, is rather the key to success in this technique.

lifeinfocus

ziggy53 wrote: »

In other words, without knowing your intent for the shot and without knowing the ambient light levels, it's not really practical to try to advise you on your two scenarios.

.

Perhaps a better way would be to ask photogs to just suggest what would be common high or low sync speed based on their experience.

For instance lets say:

1. Scenario one would be an outdoor early morning portrait on sunny day in full shade and need some fill light. Based on photogs' experience would it be a high or low sync speed - exact number not needed.

2. At an event, wedding for instance, and the light is fairly low fluorescent and subjects are slow dancing. Would the sync speed be high or low?

Thanks
Phil

novicesnapper

Thanks for the thread, I have been studying up on HSS just today. In particular, for the above low light scenarios #2.

Qarik

outdoors during the day, if the intent is on camera fill light..easy... just stick your flash on -3.0EV TTL, choose whatever sync speed you desire as long as you have the HSS turned on. Just expose as you would normally expose and forget the flash is on the camera. It really is that easy. If you are using ff camera fill througha diffuser (like an umbrella) this is where you will need to play wit the power to fit your taste..but typically in the shade during a sunny day it will be towards the fast end of the sync.

for low light events, "fill light" on camera (flash pointed directly at subjects) will kill your shot and I do not recommend it. (shadows and flat harsh light). Best bet is to bounce or using some kind of diffuser.

Photogbiker

All good answers so far, but maybe I see something else in your question.

The answer to sync speed is a bit apples and oranges to your question (i.e. "indoor" or "outdoor"). Indoor (low light) or outdoor (average daylight or in shade) doesn't directly dictate what you set for sync speed. As stated by Ziggy, it depends on what you intend for final look. The shutter can trip at a 60th or a 250th and the "flash exposure" won't change. The shutter exposes the ambient, the aperture exposes the flash.

If you are outdoors and you want a nice balance, then pick a shutter speed that works for the ambient light with the aperture dictated by your flash. If you want the background darker, then shorten shutter speed. Nice look sometimes. Also depends on subject. If there is fast movement you'll want to up the shutter speed to help freeze action since there will be some ambient exposure on your subject.

Indoors is trickier. Set your flash and aperture to work with your subject distance, then again adjust shutter speed to match ambient. Often in a dark venue you might end up at 1/30th, which will likely add blur so better to stay up at 1/60th and let background go dark.

So hopefully I am catching the core of your question, basically there is no rule on sync speed regarding indoor/outdoor. Shutter is more on what you want the background (ambient) to look like, and aperture is what you want the subject (flash exposure) to look like. Quarik simplified it for outdoor fill flash: -3 EV will give a nice fill to the shadows, but shutter will stay in a range that makes overall exposure look right (on auto). Will look natural. I usually go -1 to -1.5, but that is my taste and not any rule. Experiment.

Now, try rear curtain sync with a slower shutter indoors with uncle Harry dancing away. Really fun.....

lifeinfocus

Thanks all for your comments. i will experiment some. This weekend I am doing a special event at a local church to remember people in service - military, police and firemen.

Phil

lifeinfocus

Qarik wrote: »

outdoors during the day, if the intent is on camera fill light..easy... just stick your flash on -3.0EV TTL, choose whatever sync speed you desire as long as you have the HSS turned on. Just expose as you would normally expose and forget the flash is on the camera. It really is that easy. If you are using ff camera fill througha diffuser (like an umbrella) this is where you will need to play wit the power to fit your taste..but typically in the shade during a sunny day it will be towards the fast end of the sync.

for low light events, "fill light" on camera (flash pointed directly at subjects) will kill your shot and I do not recommend it. (shadows and flat harsh light). Best bet is to bounce or using some kind of diffuser.

Thanks.

I haven't used TTL much since I often use off camera flash and manual mode. Let me ask regarding your outdoor TTL fill settings. When you say " just stick your flash on -3.0EV TTL" are you saying to adjust EV settings on flash or camera? I am supposing flash.

Phil

Understand using bounce - I use Rogue Flashbender.

arodney

What I am trying to understand is why would I use a lower or higher sync speed outdoors or indoors. For indoors I suppose it is to reduce degree of other artificial light and for outdoors to include more natural light?

Phil. The trick here is to understand that when using flash and of course ambient light, you're making TWO exposures (at the same time)! Set the stobe for the exposure you desire from it onto what ever you're lighting. The Ambient light (the 2nd exposure) plays virtually no role here. To see this, setup the strobe for ideal exposure. Then play with the shutter which controls the 2nd part of the exposure, what the Ambient light affects. You'll see that by adjusting both (the strobe far less), you can control both light sources. Foreground is prefect but bkgnd (past where flash can affect exposure), is too light. Make the shutter higher, the stobe isn't affected (assuming you stay within it's sync limits), less ambient light and thus darker background. Lots of control. Set flash as you wish, then play with shutter to affect the non flash part of the image (within limitations, if you set the shutter to 1 second outside, you'd blow out the image affected by the flash too).

2. At an event, wedding for instance, and the light is fairly low fluorescent and subjects are slow dancing. Would the sync speed be high or low?

Do you want green bkgnd? Cause if you use a long shutter, you'll get exposure from that light source and since it's 'greener' then the flash, that's what you'll see. Better then a black hole behind the subject being lit by the flash but not ideal. But how about this. You place a 40M filter on the lens. That cleans up the green from the Fluorescent. You then put a 40G on the flash. That puts out green light to match the Fluorescent. You get a perfectly color balanced image AND you control how much the Fluorescent light affects exposure solely but how you control the shutter speed.

In theory you could just put the green filter on the flash, shoot raw, white balance all the green (no real need for the 40magenta as we had to use for film). Flash should freeze people in foreground but stuff exposed by the shutter could move...

Qarik

lifeinfocus wrote: »

Thanks.

I haven't used TTL much since I often use off camera flash and manual mode. Let me ask regarding your outdoor TTL fill settings. When you say " just stick your flash on -3.0EV TTL" are you saying to adjust EV settings on flash or camera? I am supposing flash.

Phil

Understand using bounce - I use Rogue Flashbender.

on the flash

lifeinfocus

Thanks to all for your valuable comments. The info. is this posting and the most recent one on PW and Nikon TTL http://www.dgrin.com/showthread.php?p=1836038#post1836038 have really helped.

Phil