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03-02-2010, 09:35 PM   #1
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Problems shooting with 540FGZ & K10D

OK ... first of all, I am sorry if I don't know enough about Flash photography because I hate reading the manual for 540.

I recently tried to shoot a fashion show and I was using K10D with the 540. It was a disaster and I was almost in tears when people walked up to me in the end asking for the photos. View: Amour Fashion Show

First of all, I need to understand the concepts in plain simple english. Here is my question:

I keep Flash at P-TTL mounted on camera, shoot in Av mode and move flash exposure up or down on the body (info -> flash -> thumbwheel). But the flash does not recycle fast even with new batteries. It was taking 7-10seconds while models passed me by. I don't know what is P-TTL or TTL.

That night, I played with the flash a bit more in a pitch dark room. I got the flash into A mode and then say that you could change ISO and aperture on the flash after hitting the S button. I believe I moved the ISO on flash upto 1600 and aperture to a setting where I could shoot a fair distance (as per the feet scale on the bottom). Then setting the camera to burst mode (shot-after-shot), I was able to shoot photos quickly. Also, pausing for a 1 minute after 10 consecutive shots the camera didn't resume quickly. In fact, I think it changed back to P-TTL by itself or maybe I touched something.

What is the logic here?

Am I supposed to match the ISO/Av on the body to that on the flash? What works best for fast shooting?

Thanks in advance,
sbw

03-02-2010, 11:03 PM   #2
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Not sure about the 540, I have it but I don't have much experience with it. So here something general

TTL means through the lens; with TTL and PTTL the camera will instruct the flash to interrupt the light at the moment that the camera has detected that there is enough light on the sensor/film for proper exposure.

In auto mode, the flash will measure the amount of light that is reflected from the subject and will cut-off the light at the moment that it thinks that there was enough light to expose the 'film' properly based on the ISO and aperture that you've set on the flash.

Regardless of the above modes:
If the distance to the subject is short, it will only take a short time before the subject is properly exposed and the flash light will be cut off after e.g. 1/10000sec. If the distance to the subject is longer, it takes longer before the subject is properly exposed (the intensity of the light decreases with the distance) and the flash light will be cut off (e.g. 1/2000s which is 5x longer compared to the earlier value).
If you choose a wider aperture or a higher ISO, the flash or camera will decide earlier (e.g. 1/20000sec) that there was enough light to expose the subject properly.

Shorter flash durations imply that the capacitor that powers the 'bulb' is not discharged as much compared to longer flash times. So you can keep on flashing continuously for a longer time when using a wider aperture or a higher ISO or when you subject is at a shorter distance.

Note that there is a minimum flash distance as well (read your camera manual). Also note that other 'rules' like required DOF and grain/noise still apply (so high ISO and/or wide apertures are not always desired).

And last advice: read up on flash photography; it's an art on it's own

Last edited by sterretje; 03-02-2010 at 11:08 PM.
03-02-2010, 11:05 PM   #3
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I recently shot a wedding with K10D which was held in a very dim Gymnasium. I found it easier to use shutter priority and PTL for fast shooting. 1/160 was used and let the camera set the aperture and set the ISO to 200 . This yielded some good results. As for recycle time that is a problem unless you have an external battery pack. Nickel Metal Hydride batteries allowing very fast recycle times but even they have to be given qiven few seconds to recover after hard use.
03-03-2010, 05:55 AM   #4
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If it's taking long to recycle, the flash is most likely firing at full power. If you raise the ISO a stop (or open up the aperture a stop), your flash would only need to use 1/2 power. If you raise the ISO AND open the aperture, you can get away with 1/4 power.

03-03-2010, 05:56 AM   #5
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Basically, with flash, the FLASH exposure is solely determined by flash power (actually duration, how long the bulb is actually firing for), aperture and ISO. Ambient exposure is determined by ISO, shutter speed, and aperture (just like without any flash), so the trick is balancing the two. If I'm indoors in a smallish room (such as in someone's house), I usually just forget about ambient since the flash is powerful enough to light up the entire room (hence the 1/180s below, if the flash didn't fire, I'd have a more or less black picture) Now although you're shooting MANUAL Mode, that's only for the ambient exposure (the exposure needle in the viewfinder will blink warning you about underexposure, but ignore that). The camera's P-TTL metering will determine the needed flash output for a proper exposure.

Here's something I wrote on another forum -
"Easy" recipe for great P-TTL flash shots -
1)Point flash at ceiling/wall (to the side or behind you, experimentation is the key!)
2)Put camera in MANUAL mode on the mode dial
3)Set FEC to +1 on the flash head

4)Shoot RAW (this allows you to recover some highlights that might get blown as a result of #3 above)

5)Set ISO to 200 (to start)
6)Set shutter speed to 1/180s
7)Set f-stop to whatever DOF you want


Now if the flash runs out of "power" because of high ceilings, you can raise the ISO or open up the f-stop to compensate. Or you can slow down the shutter to bring more ambient light into the exposure (in addition to adjusting ISO/f-stop) If the ceiling is REALLY high (like in a church), you may need a reflector to throw some of the light forward (I use the Joe Demb Flip-it).

Quick and dirty outdoor fill flash tutorial -
Basically, if your subject is in shade and the background is bright (ie under a tree) or majorly backlit, fill flash is your friend. Think of those times when you got a properly exposed background, but the subject was almost pitch black.

Put camera into Av mode, metering will set the shutter speed to expose the overall shot (which in the situations that call for fill-flash will generally be the background) based on your selected aperture/ISO.
Make sure flash is set to HSS (in case your shutter speed go faster than 1/180s) and P-TTL. Fire away! The shutter speed/f-stop/ISO will expose the background, and the flash should output enough power to light up the foreground.

Now to control the background exposure, you use exposure compensation on the camera body (which would adjust the shutter speed), to adjust how much fill for the flash exposure, you use Flash exposure compensation. The trick is balancing the two (as it is with indoor work), and that comes with experience/experimentation.
03-03-2010, 09:25 AM   #6
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QuoteOriginally posted by shadowbecomeswhite Quote
OK ... first of all, I am sorry if I don't know enough about Flash photography because I hate reading the manual for 540.
This is then the reason for your tears…


QuoteOriginally posted by shadowbecomeswhite Quote
First of all, I need to understand the concepts in plain simple english. Here is my question:

I keep Flash at P-TTL mounted on camera, shoot in Av mode and move flash exposure up or down on the body (info -> flash -> thumbwheel). But the flash does not recycle fast even with new batteries. It was taking 7-10seconds while models passed me by. I don't know what is P-TTL or TTL.
  1. there is not TTL-mode on the K10, ONLY P-TTL
  2. recycling time depends on two factors: output and battery type and condition. If the flash fires full power, it needs longer to recycle. Alkaline batteries are slower to recycle the flash. So, use at least NiMH batteries. And then you simply should avoid to use the flash at full power (see below)
  3. if you are seriously going into that kind of event photography you should buy an external powerpack for the flash. This brings recycling times down to 2-3 secs, even for full power output

QuoteOriginally posted by shadowbecomeswhite Quote
That night, I played with the flash a bit more in a pitch dark room. I got the flash into A mode and then say that you could change ISO and aperture on the flash after hitting the S button. I believe I moved the ISO on flash upto 1600 and aperture to a setting where I could shoot a fair distance (as per the feet scale on the bottom). Then setting the camera to burst mode (shot-after-shot), I was able to shoot photos quickly. Also, pausing for a 1 minute after 10 consecutive shots the camera didn't resume quickly. In fact, I think it changed back to P-TTL by itself or maybe I touched something.

What is the logic here?

Am I supposed to match the ISO/Av on the body to that on the flash? What works best for fast shooting?
Ofcourse you need to have the same ISO setting in camera and on the flash. If you just dial in a high ISO on the flash and use it in Auto-mode, you will get heavily underexposed images. Also ofcourse the flash duration (aka oputput) will be much shorter than at full power, if you set high ISO on the flash, but you do not gain anything, leaving the camera on a low ISO setting.

The very same is true for the aperture setting, this also needs to be the same on camera and on flash.

Ben
03-03-2010, 06:53 PM   #7
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Flash Problems

I don't know about the 540 and P-TTL. I have a K10D and a Nikon SB-26 and a Vivitar 285HV. So, obviously, I can't use TTL. In fact, everything I do is fully manual.

Unless I missed it, you didn't say what distance your camera was away from your subjects.

Fully manual, this is what I would do. If the distance was around 10 feet, I would set the aperture somewhere in the middle (4, 5.6, 8) and then adjust the shutter speed to give you the amount of ambient light you want in the background. A fast shutter speed will leave the background dark and a slower shutter speed will give the background more light.

An easy way to set the shutter speed is to pick your f-stop, then take a test shot without the flash. Your not concerned with anything being in focus; you are just setting the background light.

So if the background is too bright, go a little faster with the shutter speed. Conversely, if the background is too dark, slow down the shutter speed.

OK, get that, then put your flash on and simply adjust the power on the flash. If you're only ten to fifteen feet away, you probably won't need a full power setting. This is good, because if you only have to set your flash to 1/16th or 1/32nd power, your recycle times will be MUCH faster.

Anyway, set your camera for a background shot, and then adjust the flash to properly expose the subject. This works very well when your subject(s) are at a pretty consistent distance from you. If this distance varies, then you must adjust with it, or figure out the P-TTL.

I hope I didn't confuse you here.
03-03-2010, 11:10 PM   #8
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There is a lot to learn about flash photography, let alone P-TTL modes.
Fashion parades are fast enough to warrant fast shutter speeds. In that regard, I'd opt to stick with the X mode to maximise shutter speed without having to rely on extra flash power in HSS mode.

You haven't quite gotten a handle of how best to use flash looking at your catwalk results, which is a different beast altogether from the more static seated/staged/posed shot. Pentax in itself has a hard time tracking moving subjects, but the K10D more so than the K-7 or K-x. So that is one limitation.

But more importantly is the concept of how to freeze action once focus has been acquired. Brisk shutter releases straight after locking focus is necessary to avoid the subject moving away from the intended point of focus between the time focus is locked and shutter is opened. Then there's getting the right balance and quality of lighting, which the flash can only do so much of on the hotshoe. So trying to include some of the ambient lighting in your images will need a significant boost in ISO as well as a widening of the aperture. Hence the value of fast zoom lenses in this application like a 70-200/2.8

There's a lot of advice here already - it's all a matter of taking on board what works for you and running with it.
All the best with that.

03-04-2010, 04:42 AM   #9
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whenever I shoot flash, I take the camera out of any auto modes.

All auto modes generally try to shoot to satisfy the exposure without flash first, therefore in Av mode if you are stopped down, the camera will set a very slow shutter and then add flash.

if you have auto ISO on it will raise the ISO first then add flash.

when using flash it is best to shoot in manual mode.

think about your settings, specifically ISO, and Aperture because each impacts the amount of flash that you use.

Set the camera to the maximum sybc speed or close to it,, i.e. between 1/150 and 1/180.

Use a flash calculator or the scales on the flash and your working distance to determine what ISO and aperture you want so that you are using less than maximum power on each shot, therefore allowing much faster recycle times.

Also unless you are taking a machine gun approach, models at a fashion show move fairly slowly and there should not be a need to take more than 3 shots for each one as they walk down the runway and stop and pose at the end.
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