Studio flash colour consistancy, power & syncing.

[peter_macejka]

<p>Hi, can you help with 3 questions I haven't found answers to?<br>

I am planning to get some cheaper studio monolights (possibly Interfit Stellar X or XD). I have read that cheaper lights don't have that great colour consistency, is this less of an issue if your shooting B&W film or are converting digital files to B&W?<br>

If you are using more studio flashes on a shoot (more than 3), do you have to use either weaker flashes (150ws or 300ws) or stronger flashes turned down (600ws or 1000ws) so you don't wash out the image?<br>

Lastly, I've read that monolight flash durations are as 1/900th sec to 1/2900th sec, but how do these work with flash sync on a camera? Say 1/250th or 1/500th?<br>

Thanks for putting up with the newbie questions.<br>

Peter</p>

[dbcooper]

<p>a) I'd think it'd be less of an issue with B&W than color. If the lights lack color consistency, it seems to me that there could be a B&W tone shift similar to using very mild CC gels/filters, which should be quite subtle if it's visible at all (or how picky are you?). I would think a bigger problem would be if any significant shot-to-shot inconsistency occured with the total flash output where exposure would be affected.<br /> b) To me it'd be better to have too much power and turn it down rather than not have enough power and need it. YMMV. Washing out an image is something that's not entirely dependent on the strobes, but considers distances, flash modifiers, ambient light/daylight, your intent, effect, etc.<br /> c) The idea behind flash sync is to time the flash duration so that it's somewhere within the time the shutter is open, like: shutter opens/flash occurs/shutter closes. Basically, as long as the flash duration is shorter than the duration the shutter is open, it's good. Problems happen if the shutter <em>isn't</em> open (or is only partially open) somewhere during the meaningful part of the flash duration, either because the timing is off or the flash duration exceeds the time the shutter is open. You want the flash to be shorter than the shutter speed is, and timed to fire while the shutter is open. That's the basics. When you get comfortable, you can figure out first curtain firing, second curtain firing, etc. for even more control and effect. Good luck!</p>

[ellis_vener_photography]

<blockquote>

<p>is this less of an issue if your shooting B&W film or are converting digital files to B&W?</p>

</blockquote>

<p>Yes</p>

<blockquote>

<p>If you are using more studio flashes on a shoot (more than 3), do you have to use either weaker flashes (150ws or 300ws) or stronger flashes turned down (600ws or 1000ws) so you don't wash out the image?</p>

</blockquote>

<p>Mostly the latter, but often a mix of both.</p>

<blockquote>

<p>Lastly, I've read that monolight flash durations are as 1/900th sec to 1/2900th sec, but how do these work with flash sync on a camera? Say 1/250th or 1/500th?</p>

</blockquote>

<p>Flash duration and a camera's shortest X-Sync speed setting are two different things, don't give yourself a headache by confusing the two, at your level of what you are doing I would not worry about it further. The only time to really start worrying about flash duration and studying up on the subject is when the flashes you have are not freezing motion to the degree you desire. </p>

<p> </p>

[hjoseph7]

<p>I definately agree with Ellis, there has been tons of online post written about color concistency and flash duration issues that are not only confusing, but that I don't think will really affect the type of work you are doing.<br>

<br />The only time you need to worry about flash duration is when you are trying to freeze moving subjects, such as sports, models jumping up and down infront of a white background, dropletts of water, bullets flying through apples, special effects etc. Most flash units are adequate enough to freeze moderate motion, but some units like the ones I have, are simply designed for sit-down cheezy portraits, or stills. Something to think about if you ever want to move up to more complicated lighting situations in the future. Basically, as long as the flash duration on the flash unit is shorter than the sync speed on your camera, you should be OK.<br>

<br />As far as color concistency you can avoid the entire problem(and pulling your hair out) by setting your lights at equal power settings and then using distance to vary the flash output between flash units. If that is not possible, you can perform a custom white balance if your camera allows it, or use a grey card.</p>

[peter_macejka]

<p>Thank you all for your responses, they have been very helpful. :)<br>

Peter</p>

<p> </p>