another newbie question

[thebanana]

I just scored a 70mm lens for my Mamiya 645. It's the one with the leaf shutter, so the flash synchs at all speeds. My question is, what setting do I use on my Vivitar 285HV flash? Do I just use it as I normally would (estimating the distance, setting the flash on the red, blue, yellow setting etc.) Am I making this more complicated that I need to? Thanks in advance for any advice.

 

[SchwinnParamount]

sure, use the normal. The only thing you need to consider is your aperture. YOu only worry about the shutter speed if you also want ambient light to expose the film. If I have this right, the leaf shutter is not at the film plane. Rather, it is in the lens body. That means that if your flash fires before the shutter is fully open ( or after it has started to close) , you will still expose the entire frame. The length of the light pulse is much much shorter than the fastest shutter speed so there is no chance of the shutter closing before all of the light from the strobe has exposed the film.

 

[photobum]

While Vivitar made a bullet proof flash unit (283) they don't really out out as much light as they want you to believe. You might want to open up one extra stop beyond what the flash is set for. Do some testing to check for negative density.

 

[MattKing]

The shutter speed on the body is important too!

One further thing to remember when you use the leaf shutter on this lens - you need to make sure the focal plane shutter is open during the entire leaf shutter cycle. Otherwise you will leave a portion of the film unexposed.

This means that you need to set the camera's focal plane shutter to 1/8 of a second or longer.

You then choose the shutter speed on the leaf shutter according to the prevailing conditions.

Remember as well to reset the camera's shutter speed again after you change back to another (non leaf shutter) lens.

Please don't ask me how I know this

 

[thebanana]

Thanks for all the responses. I have spent the evening experimenting with the new lens. As usual, I've learned a lot from others on this site. Cheers,
John