second curtain flash sync on k5

For anyone who doesn't understand what second curtain flash sync is this is a good demo.....


Flash photography special tutorial - second curtain flash sync - cool exercise for nice effects

https://www.youtube.com/watch?v=le4ylJmJGJ0

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Now automatic 2nd Curtain Sync with an autofocus lens and a P-TTL flash is looking increasingly attractive, and well worth the money!

There's some great contributions here .... Who needs to go out taking photos when there's all these calculations to do instead?

I'm thinking about it more .... It seems to me that one logical way to think about it is to convert the fraction to a percentage, then just add a zero to get milliseconds ..... Does that sound like it works? All I need now is a surefire way to convert fractions to percentages ......

1/30th anyone? .....1/90th? .......1/200th ?

It's shown in my example, but this forum makes a mess of text formatting..

1/30 equals 0.033333 Just move the decimal point by 3 places to give
33.333 miliseconds

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Thanks again, the maths tutorials have been much appreciated! I will do some decimal point shifting for homework each night.

The next thing to consider when setting up Manual 2nd Curtain Sync with a delay in milliseconds is the exact position within the exposure period to place it. I imagine that around 2/3rds to 3/4 through the exposure is about right, but I wonder if the actual length of the flash output itself has to he considered here? (higher power outputs lasting longer than lower power ones). I can imagine that it might be possible to misjudge this and place higher power outputs too close to the end point of the exposure, and so risk losing some of the flash light against a closed shutter ......?

It doesn't take too much time to do some trial and draft a table for the shutter speed you're more likely to use. Once that's done, you're set for life.

Shutter closing too soon and leaving a black band at the bottom happens with a lot of remote triggers such as the Yongnuo RF-602. You have to use about 1/100th sec. to avoid it. It's possible that is 2nd Curtain Sync anyway

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