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Old Jul 16, 2009, 10:44 AM   #41
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For this photo I retained the increased light output of the flash unit. Next I increased the ISO setting to 1000 to get an increased shutter speed during the photo capture.
How have you increased the output of the flash and what sort of settings and mode are you suggesting are used, these are key elements that haven't yet been covered?
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Old Jul 16, 2009, 10:46 AM   #42
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Hi Feroz-

I agree that the obvious solution naturally would be to restrain the ISO level to reduce the noise. I demonstrated it as there will always be situations where you have to get the photo, no mater what.

That leaves you the option of using a software based noise reduction program like Neat Image, Noiseware, or Noise Ninja. For sake of learning and demonstration how noise can creep into a photo, in our example photo, no noise reduction software was applied.

Sarah Joyce

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Old Jul 16, 2009, 10:50 AM   #43
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Hi Feroz-

I agree that the obvious solution naturally would be to restrain the ISO level to reduce the noise. I demonstrated it as there will always be situations where you have to get the photo, no mater what.

That leaves you the option of using a software based noise reduction program like Neat Image, or Noise Ninja. For sake of learning in our example photo, no noise reduction software was applied.

Sarah Joyce
I'm a Noisware user and this level of noise would be able to be removed well, it would only cause me an issue if I was wanting to print at over A4 sizes but still it is usable so I don't think it is that major.
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Old Jul 16, 2009, 10:55 AM   #44
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Hi Mark-

As I mentioned in my reply to JohnG, because we have no idea as to the technical skill of the audience of this thread, I have been really attempting to keep the flash techniques demonstrated very simple and easy. And for that reason I have consistently maintained using P for program on the Mode Selector.

In addition we are only up to Photo Sample #6, so we will work our way into this gradually. In one photo, Flash Compensation was used to increase the flash lighting in the photo and in another we tweaked the flash unit to produce more light. The result in the photos was just about the same. However, for some readers, the use of Flash Compensation might indeed be the much easier strategy to employ.

Thanks as well for you comments about the noise. I did not think that the noise was intrusive in a major way, and as I mentioned to Feroz, noise reduction software could easily handle the noise in that photo. The point I desired to demonstrate is simply as you increase the ISO setting, the result will be an increase in noise in the photo.

Sarah Joyce

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Old Jul 16, 2009, 10:56 AM   #45
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Sarah - I'll leave it at this: The last couple photos of your husband were not good. IMO, you can choose to get the photos 'correct' before posting them and then educate your audience on how you did that (best approach) or you can continue to make excuses when other photographers point out issues with your photos. Teaching someone how to bounce a flash and adjust ISO doesn't help them if the result is a poor photo. You have a great oportunity to address this very real-life issue. But if everyone in this thread left producing photos like those last two of your husband I would say the tutorial was not very effective.
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Old Jul 16, 2009, 11:11 AM   #46
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Hi Readers of this thread-

We have had some excellent input posts and questions thus far, and I have answered each one. Hopefully, that will increase the learning potential of this thread. So be assured that any and all questions and input are warmly welcomed in this thread.

I have attempted to keep this thread both helpful, and as simple as possible so that the widest/greatest number of readers will be able to see, learn, and employ these flash techniques.

So thanks to all that have participated, and hopefully, we will see even more participation. That will move the learning effect forward nicely.

One final issue, the time I can put into this thread is somewhat time limited, as we have to depart home once more on 25 or 26 July to be in position for our next teaching contract. That means that I, personally will have to close out this thread on 26 July, so Bradley and I can go to work overseas. However, I cordially invite everyone to keep the thread going after my departure.

Sarah Joyce
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Old Jul 16, 2009, 11:19 AM   #47
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Next I increased the ISO setting to 1000 to get an increased shutter speed during the photo capture.
Sarah, if you look at the EXIF info for the photos you've posted, all except for one were using a 1/60 second shutter speed.

When you shoot in Auto, that's what you can expect in most indoor (lower) lighting. The camera sees that you're using a flash, and presets the shutter speed that way. So, what you're accomplishing by increasing the ISO speed is reducing the amount of light required for proper exposure.

That means the camera can use a shorter flash burst duration for a given aperture and subject distance since the sensor is more sensitive to light at a higher ISO speed. Shutter speed has no bearing on the amount of light the camera sees from the flash unless you exceed the x-sync speed. It only impacts the amount of ambient light seen.

Increasing ISO speed also allows more ambient light into the image for the shutter speed selected by the camera's Auto mode (if the exposure settings and lighting levels are such that ambient light is contributing to the exposure).

If you want more control over it (so you're varying the ISO speed, aperture and shutter speed during a flash exposure, allowing you to use faster or slower shutter speeds for the desired effect), your best bet is to use Manual Exposure versus Auto modes.

For example, you may want to use a 1/100 second shutter speed at ISO 200 and f/8 to let the flash provide almost all of the light (making sure your subject is within the flash range, which should be the case in a smaller room). That kind of approach can be useful if you want to help a closer subject stand out from distracting backgrounds (since you'd have very little ambient light contributing).

Or, you may decide to increase your ISO speed to ISO 800, open up your Aperture to f/5.6 and slow down your shutter speed so you've got more ambient light in the image (keeping ghosting and blur from subject movement in mind if ambient light is providing too much of the exposure).

But, if you stick with Auto modes, your control over the exposure is going to be more limited because the camera is making most of the decisions (like the 1/60 second shutter speed seen in most of your samples).
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Old Jul 16, 2009, 11:30 AM   #48
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That is excellent input, JimC-

I have been using Programed Auto on the Mode Selector to keep the thread as simple as possible. However, I am in total agreement that Manual on the Mode Selector may indeed be the better way to gain more direct control over the photo environment.

Sarah Joyce
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Old Jul 16, 2009, 11:37 AM   #49
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Programmed Auto mode can work OK in many indoor conditions, and still give you some level of control via ISO speed, as long as you're aware of what the camera is doing (which you can see by the settings in the viewfinder). Many users may be fine shooting at wide open apertures with the shutter speed selected by the camera indoors, and just using ISO speed as the main variable.

I just wanted to point out that the camera isn't actually changing shutter speeds with ISO speed in most cases when using a flash in most indoor conditions. It's just varying the flash burst length to insure your subject is properly exposed (with a shorter flash burst needed as ISO speeds are increased for a given subject distance and aperture, which also has the effect of allowing more ambient light into the image in most cases).
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Old Jul 16, 2009, 12:33 PM   #50
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You will not have to set the flash up manually by referring to the camera to subject distance, and then setting the correct aperture. Because the camera and flash unit communicate with each other, the camera "tells" the flash unit the the distance when it achieves focus, based on that distance, the flash unit decides what fraction of its flash power to utilize for the photo, and then instantly, when the flash unit fires, the camera analyzes the light in the photo environment and adjusts the ISO speed as required to get the proper exposure.
Even when using a camera that makes use of focus distance information, which will depend on the camera brand/model and lens used, as soon as you use anything other than a direct flash (i.e., you're bouncing a flash), subject distance is no longer a variable that can be accurately used.

That's because the camera has no idea how far the light from the flash is traveling, or the reflective characteristics of the ceiling or other surface you're reflecting the light from.

With modern film cameras, OTF (Off the Film) flash metering was a common practice, with the camera terminating the flash burst when it saw enough light during the exposure. However, because of the reflective characteristics of a digital camera's sensor, digital camera flash systems were designed to use a short metering preflash instead of metering the flash during the exposure. I think some of the earlier Pentax models tried to do off the sensor metering during the exposure. But, they also changed their systems to use a metering preflash instead for better accuracy.

Based on how much reflected light is seen from the metering preflash (which occurs just before the mirror flips up to take the photo with the main flash burst), the camera decides the flash burst length needed to insure proper exposure of your subject. Depending on camera model and lens used, reflected light at your focus point from the metering preflash (but not distance if bouncing) is taken into consideration. The amount of reflected light seen from a metering preflash is the primary variable used to judge the length of the flash burst needed with the vast majority of digital cameras when using a dedicated flash sytem.
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