Question about flash...

controldcontrold Registered Users Posts: 146 Major grins
edited April 1, 2006 in Accessories
Hi All,

I am contemplating a flash unit as the next upgrade to my gear. I have a question I am trying to wrap my head around and I can't seem to find a clear answer online.

Is there a relationship between using a Speedlite flash (I have a 10D) and faster shutter speeds when compared to the builtin flash? The fastest glass I have is a Sigma 28-70 2.8 and it is obviously not fast enough even at 800 ISO to catch people in animated conversation in low light.

Does using an external flash allow you to increase your shutter speed with the light it throws or is it primarily the quality and "fill" of the light you are benefiting from?

I hope this question makes sense... thanks for any insight you can provide.

- Mike
http://mikeapted.smugmug.com/

Canon 30D | 10D
Canon 10-22 | 28-135 f3.5-5.6 | 70-200 f4L | 100-400 f4-5.6L
Canon Speedlight 580EX
Kenko Extension Tubes

Comments

  • wxwaxwxwax Registered Users Posts: 15,471 Major grins
    edited March 30, 2006
    Both.

    But that's about where my knowledge of flash ends. :D

    An off-camera flash is usually more powerful than your onboard flash, so it has the potential to throw more light over a greater distance. It generally provides a larger light source, which makes for less harsh shadows. And it's off-set from your lens, which also makes less harsh shadows.
    Sid.
    Catapultam habeo. Nisi pecuniam omnem mihi dabis, ad caput tuum saxum immane mittam
    http://www.mcneel.com/users/jb/foghorn/ill_shut_up.au
  • Shay StephensShay Stephens Registered Users Posts: 3,165 Major grins
    edited March 30, 2006
    controld wrote:
    Does using an external flash allow you to increase your shutter speed with the light it throws or is it primarily the quality and "fill" of the light you are benefiting from?
    You can only increase your shutter speed up to the sync speed, which is around 1/250 +/- on many cameras. The real benefit comes from the flash providing the equivalent of a fast shutter speed. The light only lasts a fraction of a second, and effectively stops the action regardless of the shutter speed you are using.

    What you do with the light regarding quality, modifying, etc is an artistic choice.
    Creator of Dgrin's "Last Photographer Standing" contest
    "Failure is feedback. And feedback is the breakfast of champions." - fortune cookie
  • Shay StephensShay Stephens Registered Users Posts: 3,165 Major grins
    edited March 30, 2006
    ban the word harsh
    wxwax wrote:
    ...which makes for less harsh shadows. And it's off-set from your lens, which also makes less harsh shadows.
    Ban the word harsh from your vocabulary, it is deceptive and damaging to understanding lighting.

    There are two kinds of shadows, hard and soft. Hard shadows, the kind you get from a small unmodified light source like a flash head, provide great contrast, are very dramatic, and add zip and sparkle to a photo.

    Soft shadows, the kind you get with a large diffused light source lower contrast and provide soothing beautiful photos that hide surface texture, imperfections, etc.

    What most people object to in direct, on-camera flash shots is not hard shadows, it's the flat lighting. "Flat lighting" (look it up) is generally boring, ubiquitous, and unflattering for many subjects.

    Moving the light up and/or to the side, be it hard or soft, changes the lighting to one that is more flattering (butterfly, loop, etc), shows dimensions, volume, and detail.

    Until one can learn the language of lighting, one will be stunted and held back in their growth. And I think *that* learning begins with banning the word harsh from their vocabulary :D
    Creator of Dgrin's "Last Photographer Standing" contest
    "Failure is feedback. And feedback is the breakfast of champions." - fortune cookie
  • DavidTODavidTO Registered Users, Retired Mod Posts: 19,160 Major grins
    edited March 30, 2006
    Until one can learn the language of lighting, one will be stunted and held back in their growth. And I think *that* learning begins with banning the word harsh from their vocabulary :D

    Whoa, Shay. That's harsh.



    mwink.gif
    Moderator Emeritus
    Dgrin FAQ | Me | Workshops
  • pathfinderpathfinder Super Moderators Posts: 14,708 moderator
    edited March 30, 2006
    Harsh indeed.:):

    But accurate as wellthumb.gif
    Pathfinder - www.pathfinder.smugmug.com

    Moderator of the Technique Forum and Finishing School on Dgrin
  • Antonio CorreiaAntonio Correia Registered Users Posts: 6,241 Major grins
    edited March 30, 2006
    Shay gives always good advices.:): thumb.gif
    All the best ! ... António Correia - Facebook
  • Shay StephensShay Stephens Registered Users Posts: 3,165 Major grins
    edited March 30, 2006
    Don't make me do it...
    jasper.gif

    Using the name "harsh" in vain? Oh, you better believe that's a paddlin'

    hahahaha rolleyes1.gif
    DavidTO wrote:
    Whoa, Shay. That's harsh.



    mwink.gif
    Creator of Dgrin's "Last Photographer Standing" contest
    "Failure is feedback. And feedback is the breakfast of champions." - fortune cookie
  • wxwaxwxwax Registered Users Posts: 15,471 Major grins
    edited March 30, 2006
    Ban the word harsh from your vocabulary, it is deceptive and damaging to understanding lighting.

    There are two kinds of shadows, hard and soft. Hard shadows, the kind you get from a small unmodified light source like a flash head, provide great contrast, are very dramatic, and add zip and sparkle to a photo.

    Soft shadows, the kind you get with a large diffused light source lower contrast and provide soothing beautiful photos that hide surface texture, imperfections, etc.

    What most people object to in direct, on-camera flash shots is not hard shadows, it's the flat lighting. "Flat lighting" (look it up) is generally boring, ubiquitous, and unflattering for many subjects.

    Moving the light up and/or to the side, be it hard or soft, changes the lighting to one that is more flattering (butterfly, loop, etc), shows dimensions, volume, and detail.

    Until one can learn the language of lighting, one will be stunted and held back in their growth. And I think *that* learning begins with banning the word harsh from their vocabulary :D

    Gee, what'd I do to you? headscratch.gif

    :beatwax
    Sid.
    Catapultam habeo. Nisi pecuniam omnem mihi dabis, ad caput tuum saxum immane mittam
    http://www.mcneel.com/users/jb/foghorn/ill_shut_up.au
  • Shay StephensShay Stephens Registered Users Posts: 3,165 Major grins
    edited March 30, 2006
    Your supposed to say, "thank you sir, may I have another"...sheesh! mwink.gif

    hehehe, no, actually, I was using your post as a topic springboard. I tried generisizing, generic-i-sizing, er, making it generic, but it looks like I failed rolleyes1.gif

    Sorry if you felt jumped on :):

    now drop and give me twenty!!!
    wxwax wrote:
    Gee, what'd I do to you? headscratch.gif

    :beatwax
    Creator of Dgrin's "Last Photographer Standing" contest
    "Failure is feedback. And feedback is the breakfast of champions." - fortune cookie
  • wxwaxwxwax Registered Users Posts: 15,471 Major grins
    edited March 30, 2006
    Revenge shall be mine.
    Sid.
    Catapultam habeo. Nisi pecuniam omnem mihi dabis, ad caput tuum saxum immane mittam
    http://www.mcneel.com/users/jb/foghorn/ill_shut_up.au
  • Bob BellBob Bell Registered Users Posts: 598 Major grins
    edited March 30, 2006
    I'll bow down to the wedding photographer on hard and soft shadows since harse lighting is usually used in relation to a high sun and high contrast conditions.

    I am not sure about the 20D and it limits flash guns and what its xsync is.

    Flash guns can be used for a lot of things, bouncing creating a soft light for portraits. Using a Better Beamer(fresnel lens) to focus the flash increasing its intensity. And with a 550ex and I assume the 580ex you can use HSS to push the flash duration to a point to stop almost any action.

    The thing about flash is its very simple to use, but difficult to master for advanced techniques.

    I was testing a 550ex the other day with a 20D and was getting 1/8000 sync in HSS mode. That will stop motion a bullet.
    Bob
    Phoenix, AZ
    Canon Bodies
    Canon and Zeiss Lenses
  • ziggy53ziggy53 Super Moderators Posts: 24,127 moderator
    edited March 30, 2006
    Bob Bell wrote:
    ... I was testing a 550ex the other day with a 20D and was getting 1/8000 sync in HSS mode. That will stop motion a bullet.

    Bob,

    Unfortunately, FP mode (Focal Plane), sometimes called, High-Speed Sync (HSS), does not have the stop motion capabilities that many folks think. It is best explained here, http://photonotes.org/articles/eos-flash/#fp, but briefly, in FP mode the motion stopping capability is the same as the shutter-sync. It's just that the slit is much smaller moving across the image plane at 1/8000 sec, but it still completes the motion in the time of shutter x-sync, which varies by camera body, and the e-flash is strobing the entire time. As a result, much of the flash energy is wasted and the resulting equivalent power output is diminished according to the width of the shutter slit.

    FP mode is mostly useful in controlling ambient light with subjects that are not moving faster than the x-sync shutter speed can stop.

    Most Canon digital SLR cameras sync at 1/200th or 1/250th sec, as does the Nikon D2X. The 1D syncs at 1/500th as do many of the Nikon digital SLRs. (Nikon D100 is 1/180th sec.)

    Interestingly ...

    Many digicams have no mechanical shutter, and they can legitimately sync at ridiculous speeds. I have regularly synced both a Sony F828 and a KM A2 at very high shutter speeds with full x-sync, and neither has an FP mode.

    Also see: http://www.kenrockwell.com/tech/syncspeed.htm#fp and http://www.canon.co.jp/Imaging/flashwork/ettl2/high/index.html for some additional information on FP mode.

    ziggy53
    ziggy53
    Moderator of the Cameras and Accessories forums
  • Shay StephensShay Stephens Registered Users Posts: 3,165 Major grins
    edited March 30, 2006
    ziggy53 wrote:
    Many digicams have no mechanical shutter, and they can legitimately sync at ridiculous speeds.

    Good post!

    Cameras with leaf shutters can sync at very high speeds too. There are a number of digicams that fall under that category.
    Creator of Dgrin's "Last Photographer Standing" contest
    "Failure is feedback. And feedback is the breakfast of champions." - fortune cookie
  • Bob BellBob Bell Registered Users Posts: 598 Major grins
    edited March 30, 2006
    ziggy53 wrote:
    Bob,

    Unfortunately, FP mode (Focal Plane), sometimes called, High-Speed Sync (HSS), does not have the stop motion capabilities that many folks think. It is best explained here, http://photonotes.org/articles/eos-flash/#fp, but briefly, in FP mode the motion stopping capability is the same as the shutter-sync. It's just that the slit is much smaller moving across the image plane at 1/8000 sec, but it still completes the motion in the time of shutter x-sync, which varies by camera body, and the e-flash is strobing the entire time. As a result, much of the flash energy is wasted and the resulting equivalent power output is diminished according to the width of the shutter slit.

    FP mode is mostly useful in controlling ambient light with subjects that are not moving faster than the x-sync shutter speed can stop.

    Most Canon digital SLR cameras sync at 1/200th or 1/250th sec, as does the Nikon D2X. The 1D syncs at 1/500th as do many of the Nikon digital SLRs. (Nikon D100 is 1/180th sec.)

    Interestingly ...

    Many digicams have no mechanical shutter, and they can legitimately sync at ridiculous speeds. I have regularly synced both a Sony F828 and a KM A2 at very high shutter speeds with full x-sync, and neither has an FP mode.

    Also see: http://www.kenrockwell.com/tech/syncspeed.htm#fp and http://www.canon.co.jp/Imaging/flashwork/ettl2/high/index.html for some additional information on FP mode.

    ziggy53

    Ziggy, That is interesting. When I put the camera in M(Im always in M or AV) and the flash in M I don't see any strobing. I wonder if the flash can strobe faster in HSS than it can in multi. I always thought FP was only in TTL.
    Bob
    Phoenix, AZ
    Canon Bodies
    Canon and Zeiss Lenses
  • ziggy53ziggy53 Super Moderators Posts: 24,127 moderator
    edited March 31, 2006
    Bob Bell wrote:
    Ziggy, That is interesting. When I put the camera in M(Im always in M or AV) and the flash in M I don't see any strobing. I wonder if the flash can strobe faster in HSS than it can in multi. I always thought FP was only in TTL.

    Bob,

    I'm not sure if I understand your question, but the shortest duration for any modern electronic flash unit is in an "auto" mode, flashing across an extremely short distance. I believe this includes E-TTL (Canon) and I-TTL (Nikon) when they are not pre-flashing.

    Manual mode can also be extremely fast at extremely small output, i.e. the Sigma 500 Super at 1/128 is probably down around 1/10,000 sec or better. (The full output duration is around 1/700 sec.)

    FP/HSS mode causes the flash duration to increase to cover the entire time the shutter curtain is moving, whatever the x-sync is for the given camera. During this time, the flash is strobing at around 50,000 Hz.

    If I understand the technology, no guarantees here, the FP mode flashes are triggered by the first curtain signal, and the flash starts strobing at 50,000 cycles-per-second. Either the flash simply times out at 1/150th sec or so, or simply sumps it's entire capacitor, or the second curtain signal shuts down the burst. It's not known which of these technologies are employed, because the manufacturers are strangely not revealing how the technology of their individual flashes work. I only found vague references to any of these methods, so I consider them all to be somewhat suspicious and rumor.

    ziggy53
    ziggy53
    Moderator of the Cameras and Accessories forums
  • Bob BellBob Bell Registered Users Posts: 598 Major grins
    edited March 31, 2006
    ziggy53 wrote:
    Bob,

    I'm not sure if I understand your question, but the shortest duration for any modern electronic flash unit is in an "auto" mode, flashing across an extremely short distance. I believe this includes E-TTL (Canon) and I-TTL (Nikon) when they are not pre-flashing.

    Manual mode can also be extremely fast at extremely small output, i.e. the Sigma 500 Super at 1/128 is probably down around 1/10,000 sec or better. (The full output duration is around 1/700 sec.)

    FP/HSS mode causes the flash duration to increase to cover the entire time the shutter curtain is moving, whatever the x-sync is for the given camera. During this time, the flash is strobing at around 50,000 Hz.

    If I understand the technology, no guarantees here, the FP mode flashes are triggered by the first curtain signal, and the flash starts strobing at 50,000 cycles-per-second. Either the flash simply times out at 1/150th sec or so, or simply sumps it's entire capacitor, or the second curtain signal shuts down the burst. It's not known which of these technologies are employed, because the manufacturers are strangely not revealing how the technology of their individual flashes work. I only found vague references to any of these methods, so I consider them all to be somewhat suspicious and rumor.

    ziggy53

    Its not a question its an observation that I don't see the flash strobe. If a 550ex is capable of 50,000 cycles a second I would be surprised. I understand how FP works in TTL I just cant find anything about shooting in manually or using only the center pin on the flash to do a straight trigger and not communicate to the flash.

    I can't think of a single use that I would every use this for, for me that is, but it is a pretty interesting topic.
    Bob
    Phoenix, AZ
    Canon Bodies
    Canon and Zeiss Lenses
  • ziggy53ziggy53 Super Moderators Posts: 24,127 moderator
    edited April 1, 2006
    Bob Bell wrote:
    Its not a question its an observation that I don't see the flash strobe. ...

    Bob,

    Humans can't distinguish the 30 frames-per-second of television. If you said you could see the strobing action, I would worry about you. :):
    Bob Bell wrote:
    ... If a 550ex is capable of 50,000 cycles a second I would be surprised. ...

    One of the links I included in the previous post is from Canon itself: http://www.canon.co.jp/Imaging/flashwork/ettl2/high/index.html

    On that page Canon explains, "... the FP high-speed sync flash setting fires repeatedly at roughly 50kHz intervals during the exposure to achieve flash synchronization at all shutter speeds." So I guess we can call you "surprised". :):
    Bob Bell wrote:
    ... I can't think of a single use that I would every use this for, for me that is, but it is a pretty interesting topic.

    You use FP/HSS mode to control ambient light against the light coming from the flash. You can increase the shutter speed beyond normal x-sync speeds, allowing the use of larger apertures. Daylight fill is a classic application. That's a major benefit. Outdoor event photography, as long as you don't exceed the reduced effective distance (reduced effective GN), would benefit greatly, for instance.

    It's just not appropriate to use FP mode for, "... stop motion a bullet.", which, by the way, I also mistakedly believed before I researched the technology. (Although, if you "tossed" a bullet into the air, and photographed it at it's apogee, FP mode would be appropriate to control ambient light. ylsuper.gif )

    Thanks,

    ziggy53
    ziggy53
    Moderator of the Cameras and Accessories forums
  • Bob BellBob Bell Registered Users Posts: 598 Major grins
    edited April 1, 2006
    ziggy53 wrote:
    Bob,

    Humans can't distinguish the 30 frames-per-second of television. If you said you could see the strobing action, I would worry about you. :):



    One of the links I included in the previous post is from Canon itself: http://www.canon.co.jp/Imaging/flashwork/ettl2/high/index.html

    On that page Canon explains, "... the FP high-speed sync flash setting fires repeatedly at roughly 50kHz intervals during the exposure to achieve flash synchronization at all shutter speeds." So I guess we can call you "surprised". :):



    You use FP/HSS mode to control ambient light against the light coming from the flash. You can increase the shutter speed beyond normal x-sync speeds, allowing the use of larger apertures. Daylight fill is a classic application. That's a major benefit. Outdoor event photography, as long as you don't exceed the reduced effective distance (reduced effective GN), would benefit greatly, for instance.

    It's just not appropriate to use FP mode for, "... stop motion a bullet.", which, by the way, I also mistakedly believed before I researched the technology. (Although, if you "tossed" a bullet into the air, and photographed it at it's apogee, FP mode would be appropriate to control ambient light. ylsuper.gif )

    Thanks,

    ziggy53

    Thx again for your explanation
    Bob
    Phoenix, AZ
    Canon Bodies
    Canon and Zeiss Lenses
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