What on earth are you trying to freeze??

There will be some minor variation in flash duration, but I can't imagine we're talking about anything significant in anything I can think of! With a scene that has dark ambient conditions, the flash duration should be in the realm of 1/1000 to 1/20000s (mainly depending on power output).

The main question is how much light do you get for a given brief flash. More expensive gear can deliver larger amounts of light in a shorter time - but even the slooooowest flash is going to be shorter than 1/1000s.


It'd be helpful to see an example of what you're trying to achieve


Normal curtain: Shutter opens; Flash fires; shutter stays open for the selected duration; shutter closes.

Trailing curtain: Shutter opens; shutter stays open for the selected duration; flash fires; shutter closes.

So - no difference except for when the flash fires.

Matt

Huh?

If the flash is the primary source of light then the flash will always be faster than the shutter!!! A typical flash is something like 1/10000s. And yes, the lower the power the faster the flash.

(Shutter speed will have nothing to do with an image that is lit primarily and mainly by flash.)

If the ambient light is within 1 or 2 stops then the flash will have a limited "freezing" ability - which is why you have the "Trailing Curtain Sync" option

Best way to tell: set camera to "M"; set up the aperture and shutter speed for your flash; if the metering bar isn't all the way to the left then the ambient lighting will have an effect.

Does that make sense?
(And have you got my e-book on flash??)

Matt

I suppose it comes down to what you perceive as a "problem"

All flash systems have limits - and this is probably the biggest mistake a new user will make. Most of the issues arise when you're trying to get tons of light in a dark place out of a small flashgun with a low ISO and a small aperture!!
The biggest improvement in flash usage comes from fully understanding what the limits are; what you can do about changing things; and how to turn it to your advantage.

So, I suppose there will probably be an improvement in auto metering on the K7 - but you'll still have the limitations to respect, and the design and philosophy will no doubt be very similar to the previous bodies.

But, when they hit the streets, I'm more than happy to test it out fully if someone wants to loan me a K7D for a few months

Matt

Neil - no.
My e-book took ages to sort out! You'll notice that much of it isn't even in the manual, let alone the specification!

Still, if anyone wants me to add the K7D to the e-book, I'm happy to do that if they can loan me the K7 Any takers?

Matt

Quick answer: Z-Pro works just fine for the 12-24.
I have the Lee holder + Cokin Z-Pro ND grads. Very nice.

I can make the P size work with almost no vignetting by hacking a Cokin P holder - cutting it down to one slot and filing out the inside rim If I want to travel light that's what I use. You can also just get the polariser to work.

Matt

Nope. It's an 11 x 7 all-new matrix metering system. Check out the Pentax web sites Clarky
Matt

Erm, they look pretty fine exposure-wise to me
The only thing that I notice is the contrast in them - the difference between sky and foreground. Looks like the sky is absolutely correctly exposed (any brighter and you'd lose detail completely).

These contrasty scenes would benefit from a Shadows/Highlights adjust in Photoshop/Elements (Or "Fill Light" in Google Picasa)

Also, have you calibrated your monitor?? That can make a huge difference to how you perceive images on your PC

Matt

£175 from SRS Microsystems - with a 2 year Pro Guarantee
Here
Give Chris a ring
Matt

I'm pretty certain the trigger voltage of the 45CL series will be just fine. When using the "dumb" adapter you should set the camera to manual, or Av mode - set the aperture and ISO on both camera and flash and use a shutter speed slower than 1/180s.

NOTE: If you use Av mode, make sure the camera is in fixed ISO mode, not automatic!!

The SCA3702 may fit onto your SCA controller for the 45CL-4 (I'm not sure). I use the SCA3702 on the Metz 50MZ5 gun and it provides the correct tethering of ISO and Aperture - so Av mode on the camera is a breeze. Check out the Metz website for manuals and compatibility lists.


I also have an "e-book" PDF that you can purchase which gives some extra hints for setting up the K20D etc and using flash

Matt

Thanks for the tip Ade