Fast primes, 580EX II, and ND filters?

Sorry if this is the wrong section to post this question but I didn't know where else to post it.

For those of you that use the 50L or 85L (or any fast prime) wide open with external lighting for outdoor portraits; what (if any) ND filters do you use? I plan on using both of these lenses wide open outdoors with a 580EX II.

If I were shooting at iso 50/100, 1.2, and an external speedlite how many stop ND filter would I need to purchase so I don't over expose the scene/subject? .3, .6, 1.8...?

Any input is greatly appreciated. Samples with exif would be great too. Thanks in advance!

-tyler

The usual outdoor setting is about 1/500 f/11 ISO 200, so if you want to use f/1.2 the settings will be:

1/200 (because the maximum flash sync)
f/1.2
ISO 50
+ 6 stops ND Grad

Just get a variable ND filter...

http://www.bhphotovide​o.com …4&N=4256189595+​4242329424

I rarely use flash, you don't need to sync @1/200, you can shoot till 1/800 and still get same speed as 580EX/430EX (it's the real flash speed).
I just tried, you can even shoot @1/8000 and still get flash working perfectly.
Why would you need a ND filter with flash , anyway it will freeze action so you can use any speed you want ?

high speed sync will help your shutter speed.

Thanks for all the input folks. I guess I'll just need to go out and experiment.

-tyler

Why grab a fast prime and then use flash? Guess I never thought of trying that combo. Can't one put your flash into a manual mode and then cover it with something to cut down the output?

I want to keep the DOF of 1.2 - 2.0, but I may want to use fill flash in harsh lighting conditions. I understand where you are coming from about purchasing a fast prime only to use flash, but I intend to use the lens wide open with some fill flash. Thanks for taking the time to read and reply to my post.

-tyler

Tyler unless you shooting groups where you need to stop down, you can rely on HSS mode of your flash when shooting with fast primes. I do it all the time with my cheapy 30mm f1.4.

At f1.4 and 1/800

Bobby, thank you very much for the examples! That's exactly the type of examples I was looking for. Looks like I can save myself some money and pass on the ND filter.

-tyler

Get Syl Arena's Speedlite book before you buy another piece of gear.

newworld666 wrote in post #11959371
I rarely use flash, you don't need to sync @1/200, you can shoot till 1/800 and still get same speed as 580EX/430EX (it's the real flash speed).
I just tried, you can even shoot @1/8000 and still get flash working perfectly.
Why would you need a ND filter with flash , anyway it will freeze action so you can use any speed you want ?

So you can properly expose a bright background (IE the sky, grass) and a subject thats darker

Robertogee wrote in post #11964488
Get Syl Arena's Speedlite book before you buy another piece of gear.

Thanks for the suggestion, I'll look into it.

-tyler