I have K-5, 16-50, and YN560ex flash light.

I'm studying about control the light at outside. Since my camera can not be use when the SS is over 1/160 or 1/180, I can't use my flash light. Also Even I use it, the back ground become too dark...

Should I buy TTL supported Flash?

[DVaughan007]

Hey mate,
Try using a nd filter to reduce light otherwise stop down. The results will depend on how powerful your flash is.
Cheers
Dan

[adwb]

Buy a flash meter and learn to trust it or learn that at (for example ) f8 and the flash at 1/2 power it needs to be 3 meters from the subject to give you a decent exposure, the shutter speed controls the ambient as I'm sure you know so the f -stop controls the amount of flash recorded, once you have a working formula it works every time and you can adjust from there with minor tweaks.

Pttl is not all it cracked up to be it gets fooled by high contrasting scenes and large expanses of dark or white areas , not surprising as that also can fool the meter in non flash modes and the meter is used to set the flash output in pttl.

[Canada_Rockies]

adwb has the right idea. I do use a flash meter, but you can use the meter between your ears if you don't have one. The flash has a guide number for each f/stop you use and each power level on the flash. If you are using the flash to provide shadow fill, close down two stops or so from the guide number for the distance, and set the camera to give proper exposure at the new f/stop.

Example: Flash guide number = 80. Distance from you to subject, 10. Aperture is 80/10 = 8. Stop down to f/16 and adjust shutter to match for the scene. You will have perfect fill flash. If you want to brighten more, open the camera to f/11. If you want to exactly match the exposures, f/8.

[sterretje]

Example: Flash guide number = 80. Distance from you to subject, 10. Aperture is 80/10 = 8. Stop down to f/16 and adjust shutter to match for the scene. You will have perfect fill flash. If you want to brighten more, open the camera to f/11. If you want to exactly match the exposures, f/8.

I think that that is exactly the problem that OP has. With those settings, the camera might tell him / her to use 1/2000s shutter speed. So how do we work around that?

[Canada_Rockies]

Two options come to mind immediately.

- Lower the ISO. At ISO 100, f/16 @ 1/100 is bright sunlight exposure. If you are using a camera with minimum ISO of 200, that's f/16 at X sync. You can take care of 1/3 stop overexposure even on JPEG.

- Use a filter (CPL = 2 stops)