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Old Jul 23, 2007, 7:54 AM   #11
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I'd probably wait for others to try them after they finally hit the shelves (and I don't know when that will be), before I'd risk buying one, judging on the issues I've seen reported by some users of the existing models.

Here's the new one with HSS support (only the Super models have that feature):

http://www.sigmaphoto.com/news/news.asp?nID=3349

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Old Jul 23, 2007, 8:37 AM   #12
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What is the lazy eye problem everyone is talking about? Knock on wood...but i've been lucky not to have this issue with either the external flash (bounce) or pop-up flash.

I don't use the red-eye reduction (pre-flash).
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Old Jul 23, 2007, 9:45 AM   #13
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cgl88 wrote:
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What is the lazy eye problem everyone is talking about?
Some people react to a preflash, and so you end up with eyes half closed or closed from the blink it can cause. Many animals tend to be sensitive to one also.

Most modern digital cameras (including Konica Minolta and Sony models) use a metering preflash to help judge the length of the main flash needed. Most Digital Cameras are designed that way because of the reflectivity of the CCD. They don't use Off the Film Metering the way you could with film (or off the sensor metering in the case of a CCD or CMOS sensor).

This preflash (and it's actually more than one according to some people that have looked at it closely using test equipment) occurs approximately 100ms before the main flash burst, and it doesn't make any difference if redeye reduction is on or off.

Ditto for your flash mode (ADI versus preflash TTL). The metering preflash is always used. It's just so short that most people don't realize it's there. That's why you can see the flash through your viewfinder (you're seeing the preflash that's occuring just before the mirror swings out of the way, since you wouldn't be able to see the flash that occurs for the actual image through your viewfinder).

You still have the metering preflash, regardless of flash mode, unless you use a 7D with manual power settings (the 5D and Alpha don't support manual power settings for flash).

I haven't run into many people that are impacted by one. I've got a niece that it tends to an issue with in darker conditions (I've got a few images of her with partially closed eyes). But, I don't use the built in flash much either and I don't have one of the Sony or KM flashes (which also use a preflash).

One way around it is to use a flash that has it's own sensor built in to measure reflected light during an exposure. That's where a model like a Metz 54MZ3 comes in. It's got a separate Auto mode that doesn't use a preflash. Instead, it's sensor measures reflected light during the exposure and terminates the flash output when it sees enough light for the aperture and ISO speed being used. Note that this Auto mode does have some limitations (i.e.., it won't work with HSS).

You can also use an non-dedicated Auto Thryistor type flash to get around it (Sunpak 383 Super, Vivitar 285HV, etc.). For example, I use two Sunpaks (222 Auto and 333 Auto) with my 5D via an FS-1100 equivalent adapter. I just use manual exposure and set the camera and flash to match for Aperture and ISO speed and let the flash control it (terminating it's own output when it sees enough reflected light for the aperture and ISO speed).

The advantage of some of the Metz models using a newer SCA3302 foot is that they are aware of the camera settings in their Auto mode. So, you don't have to use manual exposure with them to get the same thing.

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Old Jul 23, 2007, 10:35 PM   #14
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FrankD wrote:
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Hello Hawaii Built,

Forgive me if you have already seen this but if you haven't it may be relevant to your research:

http://forums.dpreview.com/forums/re...hread=24090000

I have seensome negative comments concerning the build quality of Sigma flash units but no doubt your research will uncover that.

--Frank
Mahalo for the link.

I did see that thread, and it is indeed interesting. Even before reading it, I do have concerns regarding the sigma flash. I'm pretty sure that if I do decide to go 3rd party as an upgrade alternative, it'll be Metz.

About the lazy-eye... Jim is right; there appears to be some people who are a bit more sensitive to this phenomena. I'm bouncing 95% of my flash shots and have recently added a do-it-yo-self flash difuser as it seems this seems to help w/lazy eye (and makes for better shots in general). I am still struggling with either grossly under exposing or over exposing my shots though. I realize that a new flash isn't a magical cure-all and it does (more than likely) have something to do with the mechanics of my shooting (i.e. setting the right exposure, choosing the right metering mode/WB and such). HOWEVER, itseemsthat a number of people struggle with the same thing using the same equipment. I will continue to practice and experiment and hope for the best.

aloha

I hope that these thoughts make sense - I am trying hard not to ramble :?.
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Old Jul 24, 2007, 10:31 PM   #15
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Jim, thanks for the reponse.

Hawaii Built, what kind of flash exposure issues are you having? I might be able to help. For the kit lens, I have found so far that shots on ISO100 are very bad...no matter what exposure. ISO400 - ISO800 are very good, and a shutter of less than 1/60 (with SSS on ) works very well.

Bounce flash/diffusers work quite well and i have had beginners luck with not getting over exposure.

I generally like M or P and a slower shutter. That tends to work well.

Also use multi-segment, NOT spot meter. It will lead to over-exposure!
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Old Jul 25, 2007, 1:38 AM   #16
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cgl88 wrote:
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Jim, thanks for the reponse.

Hawaii Built, what kind of flash exposure issues are you having? I might be able to help. For the kit lens, I have found so far that shots on ISO100 are very bad...no matter what exposure. ISO400 - ISO800 are very good, and a shutter of less than 1/60 (with SSS on ) works very well.

Bounce flash/diffusers work quite well and i have had beginners luck with not getting over exposure.

I generally like M or P and a slower shutter. That tends to work well.

Also use multi-segment, NOT spot meter. It will lead to over-exposure!
Mahalo for the pointers on using this flash.

Your suggestions are spot on, as I have found most messed up shots were with the camera set to spot or center weighted. My ISO 100 shots are messed up, but it improves as I move up to 200 and above.

I have taken the advice offered on a thread I read here in the past and am shooting in a mode and keeping the aperature at f8. I really don't know why but as the poster in the thread I had read had stated, a mode in f8 offers a very high percentage of shots that are correctly exposed.

I am pretty excited as I think you may have hit the nail on the head... I'll try a bunch of shots with the camera set on multi-segment and see how they turn up.

~aloha~
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Old Jul 25, 2007, 6:45 AM   #17
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cgl88 wrote:
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Hawaii Built, what kind of flash exposure issues are you having? I might be able to help. For the kit lens, I have found so far that shots on ISO100 are very bad...no matter what exposure. ISO400 - ISO800 are very good, and a shutter of less than 1/60 (with SSS on ) works very well.!
If you use a higher ISO speed and wider aperture setting (i.e., smaller f/stop number), you're letting ambient light contribute more to the exposure for a given shutter speed.

So, the flash burst can be shorter and it often lets a bit more light from the background into a shot, which can be more pleasing to the eyes in many cases.

At higher ISO Speeds and/or wider apertures (smaller f/stop numbers), ambient light will contribute more, and if it's enough light to expose the subject without a flash, then motion blur and blur from subject movement can enter the equation.

If you're using a lower ISO speed and/or a smaller aperture setting (higher f/stop number), ambient light will contribute less and the flash will contribute more to the exposure for a given shutter speed. This can often result in a darker background (especially for a closer subject).

But, this technique can also be used to help your subjects stand out from distracting backgrounds (deliberately making the background darker).

The shutter speed has no impact on the amount of light the camera see from the flash (since it's burst is very fast, usually from 1/1000 to 1/20000 second). So, aperture and iso speed are your variables for how much light the camera sees from that flash burst, with the length of the flash burst changing as needed for proper exposure.

So, at lower ISO speeds and smaller apertures in many indoor conditions, you can go with a very slow shutter speed without worrying about blur (either from subject movement or camera shake).

That's because the subject is only exposed properly during the very short flash burst, and it has the impact of freezing the action. The flash is providing most of the light in that case since the subject would be dark without it.


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Also use multi-segment, NOT spot meter. It will lead to over-exposure
Or, it can lead to underexposure if you meter on something brighter. If you use spot metering, the camera only cares about exposing that exact spot. But, it's going to try and expose it to mid level brightness (i.e.., middle gray).

So, if you use spot metering and meter on a dark area (black tux, etc.), it's going to result in an overexposed image (it may try to brighten that black tux to a mid gray). If you use spot metering and meter on something brighter (i.e., a white dress), it may result in underexposure (it's going to try and make it darker). So, you have to be very careful of what you meter on using spot metering.

Note that the matrix (a.k.a., multi-segment) metering systems with most models will heavily weight your focus point, even though this metering mode still looks at the image as a whole (versus just a small spot the way spot metering would). The flash exposure algorithms may also take focus distance into consideration for the length of the flash burst needed. So, be careful where your focus point is with any metering mode.

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Old Jul 25, 2007, 10:56 AM   #18
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Jim~

This is starting to be a bit more clear to me. In a previou post, you mentioned that when you shoot with your sunpaks, you shoot most of your shots in manual mode with your shutter speed at 1/100 - generally leaving it there and adjusting ISO and aperature for correct exposure. This makes good sense for the reasons you had posted above.

I have also read that even though the camera is in multi-segment metering, it will tend to meter more heavily on the center. There was some talk in the past if this "weight" is given to whatever the focusing point is i.e. if the focusing point is switched from the center to one of the 9 other zones. I have not found an answer tthis yet, and will do some tinkering around with it.

Thanks again for all this info!

~aloha~
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Old Jul 26, 2007, 12:13 PM   #19
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Jim,

Thanks for the detailed and well thought out response. I will certainly try slower shutters at lower ISOs to see if I have any blur problems.

Let's say 1/5sec to 1/15sec + flash captures the scene.

I have yet to try this, but:

- ISO100 would render very little of the surroundings

- ISO200 would be better

- ISO400 would let in almost all of the surroundings

- ISO800 would fully let in the light of the surroundings.

In all cases the subject would be captured, but the background can be controlled by the ISO setting. Mind you, this is with a KIT lens. The results would be much more sensitive on a better lens (of f/2.8 or wider).
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Old Jul 26, 2007, 1:07 PM   #20
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You have to look at those things on a "case by case" basis (when you may want to "drag the shutter" using a flash for more ambient light in the image, and lighting varies a lot.

If you were in pitch dark surroundings, you could go that slow, depending on your aperture setting.

But, in surroundings where you may have enough light to properly expose a subject, it's a good idea to keep a couple of stops difference between ambient and flash for moving subjects if your shutter speeds are slow, especially at higher ISO speeds or wider apertures.

Experiment with it. ;-)

You'll start to see what I'm talking about. Heck, I've been known to keep my shutter speed set to around 1/15 to 1/30 second in some indoor environments when using lower ISO speeds, even at wider apertures. But, if you've got a lot of ambient light (daylight coming in through window shades, etc.), that may be too slow.

There is no set way you do these things (i.e., always use a certain shutter speed, etc.), and you've got multiple variables involved (aperture setting, ISO speed, amount of ambient light). If you don't have enough separation betweeen ambient and flash (i.e., your settings expose the subject without the flash contributing), you'll get motion blur if your shutter speed is too slow.

That's one reason I usually suggest using something like 1/100 second to users going to a non-dedicated flash system. That's fast enough that it would handle slow movement, while blocking out most ambient light indoors at lower ISO speeds and commonly used apertures.

It's all a matter of balance for the conditions you are shooting in.

I'm just pointing out how you can let in more ambient light when desired (slowing the shutter speed and/or using wider aperture and/or using a higher ISO speed) so that that flash is contributing less to the exposure with ambient light contributing more. But, if it contributes too much, and your shutter speed is slow enough to expose the subject, you're going to get some motion blur if you're not careful.

Changing the balance between ambient and flash will also impact your White Balance. So, you have to take those changes into consideration when letting in more ambient light, too.



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