Ground glass on Letus Extreme with EX1

[colby_gottert]

I have noticed that when using the Letus Extreme on the EX1 that I can see traces of the ground glass (even when it is vibrating) when I have the fixed lens set to a higher f-stop. For example, f8 leads to more artifacts than f4 and f 4 in not as clean as f1.8.

I have put some video up on my blog:

www.colbygottert.com (http://www.colbygottert.com)

Has anyone else noticed this?

[cheezweezl]

part of the deal with vibrating gg....

letus says not to shoot past f5.6. and no shutter speeds faster than 1/120 sec.

you could always switch to a spinner like the letus ultimate or my personal pref. the redrock m2 encore. you can stop way down and use fast shutter with these.

[MitchLewis]

Sorry you're just hearing about this now. I thought this was widely publicized. We bought the Ultimate so we didn't have to deal with this issue.

Sounds like you've got a good handle on the work-around though. Good luck. :)

[colby_gottert]

Thank you for your feedback guys. One thing that I have noticed is that the ground glass artifacts are much more of an issue shooting at 1080 on the EX1 than 720 on the HVX because the resolution of the EX1 image is so much higher.

The work around has worked thus far and I hope to get a chance to test the ultimate sometime in the near future.

[MitchLewis]

Don't forget that the f-stop on your EX1 makes a difference as well. Most people try to shoot around F/4.0. If it's set too high (above f/5.6) then the increased DOF will start to bring the ground glass in focus.

I should confess, that I have no hands-on experience with a Letus Extreme, I'm just passing on what I have read. Thought it might help. :)

[cheezweezl]

Don't forget that the f-stop on your EX1 makes a difference as well. Most people try to shoot around F/4.0. If it's set too high (above f/5.6) then the increased DOF will start to bring the ground glass in focus.


if i'm not mistaken, i think it's the other way around. you absolutely want the gg in focus, you just don't want to see the grain.

if you shoot at around f4 on the ex, it makes the image sharper because the deeper dof helps with minor gg wobble and edge softness. for that matter, any lens is sharper when stopped down a bit. just don't stop the ex down close to it's limit because it starts to get soft. i try to keep the ex between f4 and f8. that to me is the sweet spot.

going over f4 on the ex wouldn't make the gg grain more evident. going over f4 on the 35mm lens however, will bring out the grian. and shooting at high shutter speeds "freezes" the grain, making it visible.

[MitchLewis]

Oops! You're right. My mistake. ^^^^^what he said^^^^^