Shutter Speed in the Studio
vdotmatrix
Registered Users Posts: 343 Major grins
After having done this (photography) for an eternity and having a very close and intimate relationship with my light meter, photovision target, setting custom WB, shooting in raw and loving my MarkIIN, my freind did something that sent me for a loop.
We were testing some setups and I was taking a reading from a double bank of (8 total) T8-4ft long flouscent lights that came with our studio that happen to be about 5ft in front of the BG. To me, that was a lot of light I would have to account for in the exposure sooner or later. I took a reading.
Then I took an intial measurement of the light from a 3x4ft photogenic softbox from a StudiomaxIII and rattled off the expsure. He said the shutter speed did not matter only the fstop. so we adjusted the light to about f8. he had set his d700 to 1/250th and we fired away. acceptable images.
Okay...we are shooting in raw. WB doesn;t matter you can fiddle with it in post. He said that the strobe fires off for such a short burst that the SS is irrelevent.
WOW.....I just came from a Scott Kelby Seminar ( which has turned my photography upside down in a fantastic life changing way BTW) and he basically sets the camera to 125th and f11 at naitive ISO and then adjusts in LR. BAMMMMM! This works well.... but I want to think interms of shutter speed in the studio and arbritrarily setting SS to within the limit of the sync. You wouldn't change the SS once you had the correct exposure anyway....but am I missing some cardinal counter-intutive exposure principle in my old age?
Given SS constant you (I) adjust exposure with f-stop of course. But if you did move the SS, your exposure would change as well: Of course RIGHT?
Let's Talk!!!:scratch
We were testing some setups and I was taking a reading from a double bank of (8 total) T8-4ft long flouscent lights that came with our studio that happen to be about 5ft in front of the BG. To me, that was a lot of light I would have to account for in the exposure sooner or later. I took a reading.
Then I took an intial measurement of the light from a 3x4ft photogenic softbox from a StudiomaxIII and rattled off the expsure. He said the shutter speed did not matter only the fstop. so we adjusted the light to about f8. he had set his d700 to 1/250th and we fired away. acceptable images.
Okay...we are shooting in raw. WB doesn;t matter you can fiddle with it in post. He said that the strobe fires off for such a short burst that the SS is irrelevent.
WOW.....I just came from a Scott Kelby Seminar ( which has turned my photography upside down in a fantastic life changing way BTW) and he basically sets the camera to 125th and f11 at naitive ISO and then adjusts in LR. BAMMMMM! This works well.... but I want to think interms of shutter speed in the studio and arbritrarily setting SS to within the limit of the sync. You wouldn't change the SS once you had the correct exposure anyway....but am I missing some cardinal counter-intutive exposure principle in my old age?
Given SS constant you (I) adjust exposure with f-stop of course. But if you did move the SS, your exposure would change as well: Of course RIGHT?
Let's Talk!!!:scratch
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Oh, you know! You know when you want to cut light the easiest way is to decrease the hole that light is coming thru...You know this. Shutter speed, especially in flash doesn't do much, not much at all. I do like your Buddy does and set mine to the highest Sync speed of the system, just to have more camera-shake latitude.
In practical terms I would agree that if the ambient is around -6 EV, compared to "your" intended primary lighting, then the ambient will do little to affect the results.
Also, I would never consider a single f-stop/shutter-speed combination to be a total solution. Use f-stops to control DOF and use shutter speed to control subject blur in the scene. Use ISOs to moderate between all of your exposure options, unless you use ISO as an effect (or if a high-ISO allows a shot unattainable with a lower ISO, for any reason).
Common Fluorescent lights are especially nasty for color photography in that they are neither continuous spectrum nor continuous burn.
Typical daylight, incandescent and fluorescent spectrum:
http://www.phys.ufl.edu/~avery/course/3400/light/blackbody_color.gif
Very old fluorescent lights that require a "starter" and electrical ballast, for instance, will "beat" at line current frequency, i.e. 60 cycles. Newer electronic ballasts are much better, but you should still be aware that light output "can" vary with faster shutter speeds, potentially affecting exposure.
Another thing to keep in mind is that most studio strobes have a longer flash duration than compact flash. There may be a visible difference in exposure between 1/250th and 1/125th, even if ambient is perfectly controlled. Test your equipment and examine the results.
Ultimately you will adopt some "shooting standards" in your studio. Use what works to your photographic goals and photographic quality standards.
Moderator of the Cameras and Accessories forums
I just wasn't completely sold on ignoring the ambient light coming from flourescent poison raining down from the evil light fixtures above. I have spent hundreds if not thousands of dollars to control the quality of light in the studio only to worry about ambient poison light! In the olden days it was a greenish-yellow telltale that you shot inside White Castle for a burger....
I have to measure EV directly under the light banks but there has to be some effect shooting a subject directly underneath (8) four foot long flourescent lights. I am afriad of ambient light in the studio
GRANTED: the softbox is roughly 5 feet away from the subject and the hairlight is diagonal to this , you would think there has to be some cumulative light effect....Anyway..... I have to educate myself because I don't know everything and the older I get the more I forget . Hopefully some stuff doesn't change. Thanks for the informative graphs, it paints a better picture.
Unless I was using florescent to light my subject, I wouldn't allow those lights to be on. I'd consider draggin in a small desktop lamp just to give you some work light, but I wouldn't let those florescent's contribute, and YES they will contribute via the Shutter Speed!
I could imagine allowing florescents to contribute, but they'd have be just lighting the BG.
Unless you have a specific need for these fluorescent lights, I would turn them off.
Likie Ziggy said, once the ambient light is ~six stops dimmer than than your correct flash exposure, it will not really be an issue, but why worry about it. Hit that wall switch, and turn the green rascals off. Also, at shutter speeds higher than ~ 1/60 - 1/125, some fluorescent lights banks color spectrum alternates from reddish to greenish, and can cause bizarre results at higher shutter speeds.
I use 1/160th to 1/200th for my studio lights - fast enough to dial back ambient, and slo enough to synch nicely with studio strobes which have a longer flash duration than most speedlites.
At shutter speeds lower than sych speed, shutter speed does not effect flash exposure, only ambient. Aperture affects both flash exposure and ambient exposure, of course.
This is what allows one to use high speed synch with flash speedlite units to overdrive sunlight out of doors - they use a wide aperture with a very high shutter speed to kill the ambient sunlight, and allow the flash exposure to shine through.
If you are just using a color balanced fluorescent bank to give you a white high key background, then a longer shutter speed just drives your background whiter, and once your background pixels reach 255,255,255 the background is totally fried, blown, without any detail.
Moderator of the Technique Forum and Finishing School on Dgrin
I am not one for simple and clear explainations but I couldn't agree with you more! Thanks....
Works for me. While I don't do a lot of shooting in the office it seems to match the temp of my speed lights and strobes.
As for SS versus exposure, just give it a try on your next setup. After your done with getting what you want at say 1/250, reduce the SS to 1/125, then 1/60, then 1/30, then 1/15. The only difference with a speed light would be the amount of ambient not the exposure of the main subject lit with the speed light.
This may change a little with studio strobes because , as the man Ziggy said, the duration of studio strobes is longer than speed lights.
Sam
Changing the aperture however will change the exposure.
Sam