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-   -   bright day, lens at F22....seriously? (https://www.dvinfo.net/forum/alternative-imaging-methods/467339-bright-day-lens-f22-seriously.html)

Brian Kadar November 8th, 2009 06:08 PM

bright day, lens at F22....seriously?
 
So i have the exreme on my ex1. yesterday i shot in the middle of the day, and I had to constantly shoot at F22 on my nikon lens. I didn't have any ND filters on (maybe I should have) and my camera's aperture was wide open. WOW could I see the grain on the letus! It looked pretty bad. What's the deal here, should the ND filter be on? Is the extreme really this bad for bright shooting? What am I doing wrong?

Perrone Ford November 8th, 2009 06:26 PM

Sounds like you should have had on as much ND as you could get. F22 eh? Ugly.

Daniel Bates November 9th, 2009 08:49 AM

If it's the middle of the day, it's going to be bright. Bright light means you'll need to stop the lens down or use ND filters; if you aren't using any ND, you'll have to stop down quite a bit. F/22 is hardly an unusual exposure for outdoors with a slow shutter speed and no ND.

Gerdy Vandermeersch November 9th, 2009 09:51 AM

Don't you have 2 Neutral Density filters, settings on your ex1? Just like the Canon Xha1 and several other camcorders! When I use the Letus Extreme on my Canon Xha1 outdoors I most of the time use 1/6 and sometimes 1/32. Or am I wrong?

Greetings from Belgium
G

Steve Phillipps November 9th, 2009 10:50 AM

Sounds like you know about the ND filters, so why on earth would you not use them?
Surely using the Letus you're aiming for low depth of field anyway, so even without diffraction and seeing the grain f22 makes no sense anyway.
If the 2 NDs in the EX are still not strong enough, consider an ND4 or such like on the front of the lens too.
It's not a problem, easy solutions to it.
Steve

Bob Hart November 9th, 2009 11:13 AM

Brian.


There are fairly well known limits for groundglass 35mm adaptors.

At f22 you are five stops inside of a zone where there is no longer a threat of a groundglass artifact but a promise fullfilled.

A fairly generalised rule-of-thumb for light control could be :-

Up to three f-stops of light control before the groundglass with optical ND filters in front of your Nikon lens, to help minimise diffusion flare from overlight on the groundglass. More than three stops and you may run into a IR contamination problem where blacks aquire a warm cast. There is a filter from Schneider available to deal with that.

Nikon lens aperture no tighter than f5.6. Sensible region = f2.8 - f3.5 unless chasing a really shallow depth-of-field.

Shutter speed selected "off" with switch under front of lens barrel on camcorder or no more than 1/60th sec for normal, 1/120th sec for slowmo's.

Control of light with in-camera ND filters to try to maintain the camcorder iris in the zone of about f4 - f6.3 if you can.

Final control with camcorder iris.

It might be worthwhile investigating the "jumbo" style 4x4 matteboxes out of Chandrigagh, India, vendor usually listed as "cinecity" or something similar. The upper barndoors tend to droop but otherwise they work fine. If the filter slides are of older production, you may have to shave about 0.5mm off the inside of the slide frames with a pocketknife end to get Tiffer 4x4 glass to fit inside.

Leonard Levy November 9th, 2009 09:41 PM

Did you use the in-camera ND and lower the EX's iris. You shouldn't need to shoot at f22 I don't think.

Bruce S. Yarock November 11th, 2009 01:28 AM

Brian
I find that the Extreme is unusable stopped down more that 5.6. After that, the black smudge becomes visible. I always use the in camera nd filters. I also boght an adjustable graduating nd filter form Singh-Ray, to use with my Canon 7D, and it works great.
You can also jack up the shutter speed a bit, depending on the situation.
Bruce Yarock


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