I'm so excited I could poop

[scootermcq]

I just fired a cheap ass ebay strobe at 1/6000

As a wedding photographer this is huge!! Mainly because I don't have to spend money and can knock down the sun!!

I put a flash capable of Auto FP on the camera and enabled FP on the camera. Plugged my trigger (Stratos II) into the PC sync on the camera and fired.... I do not have any shutter curtain issues, because the strobe is a long enough (slow) flash that the entire image is exposed.

This is a test image shot at 1/2000 f/4. It is not a portrait, just making sure the light would work. If you think it is the flash, think again, because it is set on commander mode with "--" for the output (meaning it will not contribute to the exposure) and for good measure, it was turned around and facing backwards.



Again, this is not a portrait, and it is not edited, I just threw up a light and fired to see if it would do what I wanted.

[sk66]

Ok, I'm confused. I completely understand and know about being able to "sync" a studio strobe at a much higher SS due to it having a longer flash duration. But if you synced the Stobe via PC cable; what is the purpose of the flash in commander mode?

Or did you mean you plugged the (optical) trigger into the strobe's PC socket? That would make more sense.
Still, I don't think FP would be required..just front curtain.

[ccting]

Dear SK,
i thought you told me that Strobes only support up to 1/200s, but now 1/6000s?????????... Hmmm overcome the sync speed by using extremely fast speed..

Let me try tonight with flashguns

Scooter, mind if you give me the link?

[scootermcq]

Originally Posted by sk66

Ok, I'm confused. I completely understand and know about being able to "sync" a studio strobe at a much higher SS due to it having a longer flash duration. But if you synced the Stobe via PC cable; what is the purpose of the flash in commander mode?

Or did you mean you plugged the (optical) trigger into the strobe's PC socket? That would make more sense.
Still, I don't think FP would be required..just front curtain.

I don't really know why Steve. I had tried before just set up regularly and I was having no luck, and was getting blackout from the curtain. I stumbled upon a blog using this "trick" to fool the camera and it worked. The reason I put it in commander mode was I did not want the flash to do any lighting. I wanted to make sure any light was from the strobe alone. It still works if you leave the flash in regular mode, but then it is doing it's pulse FP thing and adding light to the image.

Originally Posted by ccting

Dear SK,
i thought you told me that Strobes only support up to 1/200s, but now 1/6000s?????????... Hmmm overcome the sync speed by using extremely fast speed..

Let me try tonight with flashguns

Scooter, mind if you give me the link?

Sure: The Jerry Blog!: High-Speed and no CLS

[Hill Country Hack]

Nice information, but would you educate us by defining FP?

[scootermcq]

Originally Posted by Hill Country Hack

Nice information, but would you educate us by defining FP?

It stands for focal plane, but it is basically making the flash pulse instead of 1 flash, allowing the flash to exceed it's max sync speed of 1/200 or 1/250. The down side of auto fp is it greatly reduces flash power because of the pulsing

[sk66]

ccting,

There are 2 things which limit sync speed. Flash duration and the speed at which the camera can expose the entire sensor at once (camera sync speed). Typically, the flash duration is much shorter than the camera sync speed, so camera sync speed becomes the limiting factor. Particularly with external flash units.

However, studio strobes often have a flash duration (how long the light is on) which is much longer than the duration of an external flash. When this is the case the shutter speed can be increased above sync speed as long as the exposure time falls within the flash duration (and faster SS's actually work better here). The main drawback is that the exposure will tend to "fall off" towards the end because the strobes flash duration is "hottest" at the beginning with the light levels falling off quickly. Exposures tend to be "uneven". It's a bit of a "trick" and not really as things are intended to work...as such it's a "compromise solution".

We/I should probably do a better job of differentiating between "flashes" and "strobes". They are different breeds.

[sk66]

Scott,
I don't know either. The use of the strobes in the example was partly to get a sync port when the camera doesn't have one. Your camera does. What I don't understand is why TTL/FP is necessary.

I believe TTL is necessary to enable FP, that makes sense. The purpose of using FP is so that the strobes are triggered "early". I think you would get the same results without the flash/ttl/fp, using front curtain sync instead. Have you tried this? The only reason this wouldn't work is if "front curtain sync" isn't *really* at the *very front*, but I think it is.

[bhursey]

I found this for cannon. Im so gonna try this dont think it will do anything on a bright day outside.. But who knows.


Found this on a forum.

If you have a Canon flash here' s hack you can try. Put the Canon flash in the hot shoe set to HHS then let it trigger your ABs optically. HHS starts pulsing just before the shutter opens. That in turn fires the AB just before the shutter opens. Use a shutter speed on the camera shorter than the flash duration of the AB so the curtain slit passes over the sensor while the flash tube of the AB is still illuminated.

I wonder what the flash duration is on your cheep strobe?

EDIT:
.. I did see there was some success with strapping an optical slave to the front of a 580EXII and then the optical slave triggers the radio trigger. Im wondering if the LP160 will trigger a radio trigger through its pc and mono port. If so im wondering if that will work. I have to test some more.

[scootermcq]

Originally Posted by sk66

I believe TTL is necessary to enable FP, that makes sense. The purpose of using FP is so that the strobes are triggered "early". I think you would get the same results without the flash/ttl/fp, using front curtain sync instead. Have you tried this? The only reason this wouldn't work is if "front curtain sync" isn't *really* at the *very front*, but I think it is.

I don't think I tried front curtain. If I get a chance today, I will give it a whirl and see what happens.