ISO and a cheap flash gun

ecphotomanecphotoman Registered Users Posts: 109 Major grins
edited March 27, 2012 in Technique
Okay so I just purchased a 550D with a grip and had almost no money left over. I purchased a Bower SFD728C flash, cause it was 50 bucks. Here's where ISO comes in, if I set it too about 800 the recycle times go from a few seconds to about half a second. I got the idea from a video of Gary Fong on youtube, he suggested doing that when shooting weddings because it uses less juice and at ISO 800 there is virtually no noise.

My question to you all is, will I really see virtually no noise at ISO 800 or what kind of ISO's do you use in such indoor situations?

Comments

  • ziggy53ziggy53 Super Moderators Posts: 23,764 moderator
    edited March 25, 2012
    For formal images I use low ISOs and a lot of light. For candids and snaps ISO 400-ISO 800.
    ziggy53
    Moderator of the Cameras and Accessories forums
  • ecphotomanecphotoman Registered Users Posts: 109 Major grins
    edited March 26, 2012
    ziggy53 wrote: »
    For formal images I use low ISOs and a lot of light. For candids and snaps ISO 400-ISO 800.

    So would you say it would be wise to keep it to ISO 200-400?
  • johngjohng Registered Users Posts: 1,658 Major grins
    edited March 26, 2012
    It's a balancing act. It depends on your shooting situation. Doesn't matter if ISO 400 is cleaner if your shooting situation is dynamic and you are missing shots waiting on the flash to recycle. So, a shot with some noise is better than NO shot at all. With proper noise reduction software there should be no issue with ISO 800 flashed shots from your camera if the shot is properly exposed. You also have to be aware that changing ISO without changing aperture or shutter speed changes the balance of how much ambient light comes into play in the photo. The reason the flash recharges faster at ISO 800 is the camera is using more ambient light in rendering the photo.

    The more you let ambient light play a role the more you can run into different color casts (which may or may not be OK to you).
  • rsquaredrsquared Registered Users Posts: 306 Major grins
    edited March 26, 2012
    johng wrote: »
    The reason the flash recharges faster at ISO 800 is the camera is using more ambient light in rendering the photo.

    Not quite... If you change from ISO 400 to 800, you need half as much light to expose the shot. This means that with no other changes to shutter speed or aperture you only need half as much light from the flash, which is why it can recycle faster. Ambient will also double, but that may or may not come into play depending on how much of it there is. e.g. in a nearly dark room where flash was providing 95% of the light, you still won't really see any contribution from the ambient. If the ambient is contributing to the shot, you can increase the shutter speed at the same time as increasing the ISO to keep it consistent (assuming you aren't at your camera's max sync speed yet)
    Rob Rogers -- R Squared Photography (Nikon D90)
  • pathfinderpathfinder Super Moderators Posts: 14,694 moderator
    edited March 26, 2012
    The key to noise in digital images is to shoot RAW, and not under expose. Modern RAW engines do a great job if the files are not under exposed, so Expose to the right.

    Properly exposed ISO 1600 images can be quite good in prints no larger than 10 x 15 inches. ISO 800 is even better. Your effective flash guide number is much higher ( 8x) at ISO 800 than ISO 100, that is why your flash recycles so much faster.

    This image was shot as a candid, with a 40D with off camera flash, at ISO 1600. Is the noise a serious concern in this image?

    Bear in mind, I agree with Ziggy, that a lower ISO, properly shot and rendered, will give a superior image file. So, shoot the lowest ISO you reasonably can. But do not fear higher ISOs, just do not under expose them, and render them in a modern Raw converter. Use NoiseWare or a similar noise reduction software if really needed, but for most images not destined for very large prints, LR3 or LR4 should be more than adequate.
    Pathfinder - www.pathfinder.smugmug.com

    Moderator of the Technique Forum and Finishing School on Dgrin
  • ecphotomanecphotoman Registered Users Posts: 109 Major grins
    edited March 26, 2012
    pathfinder wrote: »
    The key to noise in digital images is to shoot RAW, and not under expose. Modern RAW engines do a great job if the files are not under exposed, so Expose to the right.

    Properly exposed ISO 1600 images can be quite good in prints no larger than 10 x 15 inches. ISO 800 is even better. Your effective flash guide number is much higher ( 8x) at ISO 800 than ISO 100, that is why your flash recycles so much faster.

    This image was shot as a candid, with a 40D with off camera flash, at ISO 1600. Is the noise a serious concern in this image?

    Bear in mind, I agree with Ziggy, that a lower ISO, properly shot and rendered, will give a superior image file. So, shoot the lowest ISO you reasonably can. But do not fear higher ISOs, just do not under expose them, and render them in a modern Raw converter. Use NoiseWare or a similar noise reduction software if really needed, but for most images not destined for very large prints, LR3 or LR4 should be more than adequate.

    If I'm shooting in the 600-1000 range would it be a good idea to use exposure compensation to ensure its exposed well.

    That picture looks great, is that with a prime?
  • pathfinderpathfinder Super Moderators Posts: 14,694 moderator
    edited March 26, 2012
    Thanks, that was shot 5 years ago, and edited with CS3 probably. Not too much grain??

    I used one of the best lenses Canon makes - the 135 f2.0 L - sharp, with great bokeh, and relatively inexpensive for the quality it delivers... That frame was shot at a family Christmas party at f2.2.

    Exposure compensation hmm - how do you plan to do that with a manual flash? I would suggest getting your exposure right from the get go. Use the guide number and distance method, or use a flash meter like the Sekonic 358.

    The beauty of manual flash, is that as long as the flash to subject distance does not change, your exposure does not change either, and you evan just bang away in manual mode. If you need to adjust exposure, you can move your flash for and aft to alter its brightness on your subject, or you can vary your aperture, or ISO.

    The flash in my shot was bounced out of a corner with a diffuser.
    Pathfinder - www.pathfinder.smugmug.com

    Moderator of the Technique Forum and Finishing School on Dgrin
  • ecphotomanecphotoman Registered Users Posts: 109 Major grins
    edited March 26, 2012
    pathfinder wrote: »
    Thanks, that was shot 5 years ago, and edited with CS3 probably. Not too much grain??

    I used one of the best lenses Canon makes - the 135 f2.0 L - sharp, with great bokeh, and relatively inexpensive for the quality it delivers... That frame was shot at a family Christmas party at f2.2.

    Exposure compensation hmm - how do you plan to do that with a manual flash? I would suggest getting your exposure right from the get go. Use the guide number and distance method, or use a flash meter like the Sekonic 358.

    The beauty of manual flash, is that as long as the flash to subject distance does not change, your exposure does not change either, and you evan just bang away in manual mode. If you need to adjust exposure, you can move your flash for and aft to alter its brightness on your subject, or you can vary your aperture, or ISO.

    The flash in my shot was bounced out of a corner with a diffuser.

    Well I'm still figuring out this camera. I upgraded from a Sony @330 less than a week ago.

    So far ttl2 performance with this flash isn't so good using Av. It keeps giving me very slow shutters and I keep getting the drag effect...every time lol.

    So i tried the same composition with the manual mode set to 1/60 and 3.5f and the flash to auto and ISO800, I was about two stops underexposed. It filled everything in just fine.

    You think I'm having that issue with Av mode because its a cheap ettl2 flash rather than one by Canon?
  • ziggy53ziggy53 Super Moderators Posts: 23,764 moderator
    edited March 27, 2012
    ecphotoman wrote: »
    ... So i tried the same composition with the manual mode set to 1/60 and 3.5f and the flash to auto and ISO800, I was about two stops underexposed. It filled everything in just fine.

    You think I'm having that issue with Av mode because its a cheap ettl2 flash rather than one by Canon?

    If manual mode was ISO 800, f3.5 and 1/60th, and still 2 - stops underexposed, that's not very much light and means that you should be using ISO 3200 to correctly use Av mode in that situation. (Av mode assumes that you will use ambient light as your primary source and key light, with flash as fill light.) You can "force" Av mode to use the flash more as a primary light source by selecting more positive FEC.

    Manual mode allows you to more accurately choose the ratio of ambient to flash. If you want the flash to be your primary source of light, I suggest shooting in Manual mode.

    As Pathfinder and others have said, properly expose your subject(s) as the first priority, and if that means a high ISO setting, so be it.

    If the venue has too little ambient, and if you need the background to be illuminated at a lower ISO, use an additional flash (or a few additional flashes.) More than likely that will improve color balance as well.

    I have no experience with the Bower SFD728C, but if it continues to be unsatisfactory I can recommend the Sigma EF DG Super series of flashes in Canon mount. I have 4 of those flashes and they are very satisfying. They are not cheap, but they are very competent flashes and cost less than the equivalent Canon flashes, with nearly the same functionality. (The user interface is a lot different, but not bad, and the build quality is not up to Canon standards, but also not bad.)
    ziggy53
    Moderator of the Cameras and Accessories forums
  • pathfinderpathfinder Super Moderators Posts: 14,694 moderator
    edited March 27, 2012
    ecphotoman wrote: »
    Well I'm still figuring out this camera. I upgraded from a Sony @330 less than a week ago.

    So far ttl2 performance with this flash isn't so good using Av. It keeps giving me very slow shutters and I keep getting the drag effect...every time lol.

    So i tried the same composition with the manual mode set to 1/60 and 3.5f and the flash to auto and ISO800, I was about two stops underexposed. It filled everything in just fine.

    You think I'm having that issue with Av mode because its a cheap ettl2 flash rather than one by Canon?

    When you shoot in Av mode with ettl flash, the assumption Canon is designed about, is that you want to expose your subject with the flash AND capture the background via the ambient ( non-flash ) light, AND your camera may need a very long shutter speed for the ambient portion of the exposure. In other words, you need to have your camera on a tripod frequently when shooting ettl and Av. You will find Manual mode in the camera body and the flash in ettl works much better, if your non-OEM flash truly supports ettl.
    One Can shoot ettl with Av, but you must watch your shutter speed and be ready to use a tripod or switch to manual if the ambient begins to get dark. Ettl plus Av works better out of doors in brighter light.
    Pathfinder - www.pathfinder.smugmug.com

    Moderator of the Technique Forum and Finishing School on Dgrin
  • ecphotomanecphotoman Registered Users Posts: 109 Major grins
    edited March 27, 2012
    pathfinder wrote: »
    When you shoot in Av mode with ettl flash, the assumption Canon is designed about, is that you want to expose your subject with the flash AND capture the background via the ambient ( non-flash ) light, AND your camera may need a very long shutter speed for the ambient portion of the exposure. In other words, you need to have your camera on a tripod frequently when shooting ettl and Av. You will find Manual mode in the camera body and the flash in ettl works much better, if your non-OEM flash truly supports ettl.
    One Can shoot ettl with Av, but you must watch your shutter speed and be ready to use a tripod or switch to manual if the ambient begins to get dark. Ettl plus Av works better out of doors in brighter light.


    its all starting to make sense now. Ill save it for outside or when I don't have the time to make the manual adjusting my self.



    ziggy53 wrote: »
    If manual mode was ISO 800, f3.5 and 1/60th, and still 2 - stops underexposed, that's not very much light and means that you should be using ISO 3200 to correctly use Av mode in that situation. (Av mode assumes that you will use ambient light as your primary source and key light, with flash as fill light.) You can "force" Av mode to use the flash more as a primary light source by selecting more positive FEC.

    Manual mode allows you to more accurately choose the ratio of ambient to flash. If you want the flash to be your primary source of light, I suggest shooting in Manual mode.

    As Pathfinder and others have said, properly expose your subject(s) as the first priority, and if that means a high ISO setting, so be it.

    If the venue has too little ambient, and if you need the background to be illuminated at a lower ISO, use an additional flash (or a few additional flashes.) More than likely that will improve color balance as well.

    I have no experience with the Bower SFD728C, but if it continues to be unsatisfactory I can recommend the Sigma EF DG Super series of flashes in Canon mount. I have 4 of those flashes and they are very satisfying. They are not cheap, but they are very competent flashes and cost less than the equivalent Canon flashes, with nearly the same functionality. (The user interface is a lot different, but not bad, and the build quality is not up to Canon standards, but also not bad.)

    Thanks Ziggy, it makes sense now. I've never used Av much so I wasn't sure what to expect.
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