Some thoughts on sharpness at DVinfo.net

Peter Rixner · May 11th, 2005, 03:25 AM

Hi :)

I am using the Z1 now for several weeks and sometimes found, that the sharpness of the image is variying from shot to shot.

Of course that is because, the extreme different lightsituations lead to extreme settings like ND2 and still a high f-stop or of course the opposite with barely enough light. No - not with gain :)

So just for sharpness reasons: Did someone find a rule for the Z1, what is to prefer, when there is enough light ? Using the NDs or better increase the shutter. Depth of field isn't really usable as an artistic tool anyway.

And maybe a external ND would do a better job ?

And are high f-stops better or worse for that.

Thanks for your ideas!

__Peter__

Barry Green · May 11th, 2005, 02:12 PM

With a tiny-pixel CCD like the Z1 has, you need to avoid deep f-stops. F/11 or higher can lead to diffraction, which will cause a noticeable loss of sharpness in your video. It's mentioned in the camera manual.

Your Z1 even has a menu option that lets you limit how small the aperture can go, specifically for this reason. I think the settings are f/5.6 or f/8. Use it, if you want to avoid the softening that happens due to diffraction.

You should never go more stopped-down than about f/8... use the ND filters, or external ND filters if you need to.

George Griswold · May 11th, 2005, 03:40 PM

Barry is right about the small f-stops. Even with Fujinon and Canon 2/3" lenses thinks get visibly funky around f16. I have not really done tests but I have the smaller f-stops locked off in the profiles. I have seen the diffraction at f11. It is too bad that they don't have a -3dB sensitivity setting to help out.

You could use an external ND.. I have a few and I can report back when I get a chance to try some things. I will take shots with a monitor in full sun and see where the f-stops fall, and the approximate values of the ND filters.

George

May 11th, 2005, 03:25 AM	#1
Peter Rixner Regular Crew Join Date: Mar 2005 Location: near Munich, Bavaria Posts: 139	Some thoughts on sharpness Hi :) I am using the Z1 now for several weeks and sometimes found, that the sharpness of the image is variying from shot to shot. Of course that is because, the extreme different lightsituations lead to extreme settings like ND2 and still a high f-stop or of course the opposite with barely enough light. No - not with gain :) So just for sharpness reasons: Did someone find a rule for the Z1, what is to prefer, when there is enough light ? Using the NDs or better increase the shutter. Depth of field isn't really usable as an artistic tool anyway. And maybe a external ND would do a better job ? And are high f-stops better or worse for that. Thanks for your ideas! __Peter__

May 11th, 2005, 03:40 PM	#3
George Griswold Major Player Join Date: Apr 2005 Location: New Orleans, LA Posts: 218	Barry is right about the small f-stops. Even with Fujinon and Canon 2/3" lenses thinks get visibly funky around f16. I have not really done tests but I have the smaller f-stops locked off in the profiles. I have seen the diffraction at f11. It is too bad that they don't have a -3dB sensitivity setting to help out. You could use an external ND.. I have a few and I can report back when I get a chance to try some things. I will take shots with a monitor in full sun and see where the f-stops fall, and the approximate values of the ND filters. George __________________ George T. Griswold, Jr. www.videonow.info New Orleans

May 11th, 2005, 02:12 PM	#2
Barry Green Barry Wan Kenobi Join Date: Jul 2003 Location: North Carolina Posts: 3,863	With a tiny-pixel CCD like the Z1 has, you need to avoid deep f-stops. F/11 or higher can lead to diffraction, which will cause a noticeable loss of sharpness in your video. It's mentioned in the camera manual. Your Z1 even has a menu option that lets you limit how small the aperture can go, specifically for this reason. I think the settings are f/5.6 or f/8. Use it, if you want to avoid the softening that happens due to diffraction. You should never go more stopped-down than about f/8... use the ND filters, or external ND filters if you need to.