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Old Oct 22, 2006, 8:58 AM   #1
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I am attempting to learn to use the 5600HS (D)flash with my Minolta Maxxum5D. When I use it in A priority, the shutter speed does not change as I change the A except at extremes, or if I change focal distance on zoom lens. The same is true in S priority: the aperture does not change asI change the shutter speed. This means that some photos are properly exposed and some are not. What is wrong?

Thanks! Anita
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Old Oct 22, 2006, 4:38 PM   #2
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Most cameras use a fixed shutter speed with flash, since the flash provides most of the lighting, and shuttter speeds too slow would cause motion blur indoors with most lenses unless using very high ISO speeds (i.e, 1600 or 3200) and/or brighter lenses. So, regardless of aperture, the shutter speed is probably going to stay the same in most indoor lighting with flash.

With shutter priority, your shutter speeds are probably set too fast for it to use anything except for wide open apertures, too. Light is much dimmer to a camera's lens compared to the human eye. At lower ISO speed settings, you may need exposures of 1/8 second or slower with most lenses indoors without a flash, even at wide open apertures. So, in order for the camera to use a smaller aperture (higher f/stop number) indoors with shutter priority mode, you'd need pretty darn good light (or very high ISO speeds) using anything but the slowest shutter speeds.

So, exposure is controlled via the flash burst length, with shutter speed kept to a reasonable value. Basically, the camera uses a short pre-flash and measures the amount of reflected light seen from your subject (heavily weighted for your focus point with KM DSLR models). Then, it adjusts the length of the main flash burst for proper exposure at the ISO speed and aperture you're using.

Shutter speed has no impact on the amount of strobe produced light seen by the camera in most conditions (because the flash burst is usually 1/1000 second or faster). So, the camera sees the exact same amount of light from the flash at 1/100 second as it sees at 1/10 second. ;-) What changes with shutter speed is the amount of ambient (non flash) light seen by the camera, and in most indoor conditions, the flash will be providing most of the light.

If you have a genuine need to control the shutter speed to let in more or less ambient light, use manual exposure instead.

In non-Manual modes, your 5D can also meter for ambient light using a flash if you press and hold the AEL button (meter, then keep it held down to lock the metered exposure while taking the photo).

This AEL button can also be setup as a toggle in the menus (press once and it meters and locks exposure for ambient light, press again and it releases the lock). Basically, it meters for ambient light instead of flash, and uses the appropriate shutter speed for ambient light instead, using only a small amount of fill flash. But, this means that shutter speeds are going to be much slower indoors, and you'd risk motion blur that way unless using a brighter lens at higher ISO speeds and wider apertures (smaller f/stop numbers)


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Old Oct 22, 2006, 9:22 PM   #3
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Jim: I appreciate your reply. I need to read it again tomorrow and take some photos based on what you write to fully understand it. I want to thank you now, though. I think this is the answer I need. I feel reassured. Many thanks!!

Anita
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Old Oct 22, 2006, 10:11 PM   #4
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Unless you have a very specific need to control shutter speeds, your best bet is probably to use Av (Aperture Priority) mode for Depth of Field control. Then, let the camera handle the rest.

If you need more ambient light, use a bit higher ISO speed with wider apertures (smaller f/stop numbers) so that ambient light contributes more to the exposure at the camera's default shutter speed for flash.

As for exposure accuracy, the KM models heavily weight your focus point for exposure, even when using Matrix metering. So, keep that in mind when using one.

I keep my 5D setup so that I select a focus point, and try to be careful what I focus on for metering purposes, too (trying to focus on a relatively neutral area versus a portion that's too dark or too bright compared to the rest of the scene), because the KM models place more emphasis on the focus point compared to the matrix metering in most systems.

Experiment with the AEL button if you want to meter more for ambient light. Just keep shutter speed in mind (you can get a bit of motion blur if you let the camera meter for ambient light using the AEL button with flash if you're not using a wider aperture and higher ISO speed in most indoor conditions, since shutter speeds can get relatively slow that way).

If you want even more control, use Manual Exposure instead. I use a KM 5D, too. But, I went with a cheap flash system for mine. I use a Sunpak 333 Auto ($25 in like new condition from B&H) via an adapter (equivalent to the Minolta FS-1100) to give the 5D an ISO standard hotshoe. So, I have to use manual exposure with my strobe, since the camera isn't even aware that it's there. :-) But, I usually keep shutter speed set to around 1/100 second in most indoor lighting using it anyway.

Also, keep in mind that the flash sync speed on your camera is limited to 1/125 second with AS on, or 1/160 second with AS off. So, even if you use manual exposure, you'd probably want to keep shutter speed around the sync speed or slower in most indoor conditions. Otherwise, you'll be using the HSS (High Speed Sync) feature of your 5600. That means that the strobe has to "pulse" the light as the shutter curtain moves across the frame, which significantly reduces your flash range at anything above the default flash sync speed (1/125 second with AS on, 1/160 second with AS off).

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Old Oct 23, 2006, 8:52 PM   #5
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Jim:

I understand what you write about using Av for depth of field control. I experimented with it last evening and was pleased with the results.

"As for exposure accuracy, the KM models heavily weight your focus point for exposure, even when using Matrix metering. So, keep that in mind when using one."

This was very helpful information. It explains the results I got on some of my shots, even when I switched from spot focus to multi-segment.

"Experiment with the AEL button if you want to meter more for ambient light.... shutter speeds can get relatively slow that way)."
"If you want even more control, use Manual Exposure instead."

OK. Haven't tried these suggestions yet. Will probably get to it on Wednesday.

" keep in mind that the flash sync speed on your camera is limited to 1/125 second with AS on, or 1/160 second with AS off."

What is AS?

"...HSS (High Speed Sync) feature ... means that the strobe has to "pulse" the light as the shutter curtain moves across the frame, which significantly reduces your flash range at anything above the default flash sync speed (1/125 second with AS on, 1/160 second with AS off)."

So, does this mean that I will usually use the flash with HSS Off? When would I want to use HSS?

Many thanks. You are giving me a tutorial on using my flash!!!!

Anita
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Old Oct 23, 2006, 11:27 PM   #6
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homequaker wrote:
Quote:
What is AS?
Anti-shake

You have a switch on the camera to turn it on or off.

Quote:
So, does this mean that I will usually use the flash with HSS Off? When would I want to use HSS?
Yes, unless you are using shutter speeds faster than the camera's flash sync speed (1/125 second with AS on, or 1/160 second with AS off), HSS (high speed sync) is not needed.

So, in most indoor conditions, it would not ever be needed (you wouldn't need faster shutter speeds compared to the sync speed for most purposes).

Where HSS comes into play is when you need faster shutter speeds than the camera's flash sync speed allows (for example, when you want to use fill flash outside in brighter light at wider apertures). In those condtions, the flash can still work, even if you use shutter speeds faster than 1/125 second with AS on or 1/160 second with AS off. But, you lose a lot of flash range because the camera must pulse the light as the shutter moves across the image plane.

Otherwise, part of the frame would be dark (because the entire frame is never completely exposed to a single burst of light from a strobe at shutter speeds faster than the sync speed).

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Old Oct 24, 2006, 3:27 PM   #7
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Quote:
the camera's flash sync speed (1/125 second with AS on, or 1/160 second with AS off), HSS (high speed sync) is not needed.
It seems to me that this information ought to be in the manual that came with the flash, but, I haven't come across it. Ooops. I just found the sync speed listed af 1/125, but no reference to a different sync speed with AS off.

As to AS, I just didn't connect it with anti shake, which I understand.

Again. Many THANKS!!

Anita
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Old Oct 24, 2006, 3:34 PM   #8
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Quote:
In non-Manual modes, your 5D can also meter for ambient light using a flash if you press and hold the AEL button (meter, then keep it held down to lock the metered exposure while taking the photo).

This AEL button can also be setup as a toggle in the menus (press once and it meters and locks exposure for ambient light, press again and it releases the lock). Basically, it meters for ambient light instead of flash, and uses the appropriate shutter speed for ambient light instead, using only a small amount of fill flash. But, this means that shutter speeds are going to be much slower indoors, and you'd risk motion blur that way unless using a brighter lens at higher ISO speeds and wider apertures (smaller f/stop numbers)

I intend to try this. I use the AEL button in certain situations when not using flash, so I know how it basically works.

Flash just feels so confusing. I assume that as I practice more with it, it will make more sense. :?
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