Aperture Q for the Letus guys

S

StMad

Well-known member
What fstop can you stop down to with your 35mm lens on the Extreme/Economy?

I'm limited to f4-5.6 with the Brevis before the gg is visible, and I believe the SGpro is not limited at all.

Cheers,

Steve
 
I always thought it was limited to the amount of light available? ie - you should be able to go f8 no problem in extreme sunlight?
 
No, you adjust the camera's aperture to compensate....the attached lens needs to stay within the above parameters.
 
disjecta said:
No, you adjust the camera's aperture to compensate....the attached lens needs to stay within the above parameters.
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True. Aside from the visible grain from the GG I also noticed a hot spot in the center of the frame (more than just minor vingetting). I usually only drop down a stop or two from wide open, and then let the ND filters or camera take care of the rest. I, too, own the Brevis and Disjecta is right when he says they are similar in this manner.
 
Remember too that controlling ND from the 35mm lens will in most cases yield better results than from the camera's internal filter because you're killing the light prior to hitting the gg rather than after -
 
Aerialsfilm M* said:
Never noticed any grain when stopping down on my SGpro. Even to a full 18.
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From my experience I've found spinning adapters to be less prone to visible grain when stopping down (vibrating adapters will definitely show this quicker).
 
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Chenopup said:
Remember too that controlling ND from the 35mm lens will in most cases yield better results than from the camera's internal filter because you're killing the light prior to hitting the gg rather than after -
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I simply cannot find any truth to this.
 
Setting my Extreme and a Canon HV20 up to roughly emulate a 35mm frame size, I'm seeing noticeable vignetting at anything over f4.0 using a 50mm 1.8 Nikon lens. I'm still testing the setup to find the optimum ranges for various lenses and camera settings.

I'm going to definitely use ND filters to control exposure outdoors and keep my lenses to no higher than f5.6 with the HV20 set to 24p, 1/48 and f1.8 or 2.0. I'll adjust in-camera as the last step if necessary.
 
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Leo Versola said:
Setting my Extreme and a Canon HV20 up to roughly emulate a 35mm frame size, I'm seeing noticeable vignetting at anything over f4.0 using a 50mm 1.8 Nikon lens. I'm still testing the setup to find the optimum ranges for various lenses and camera settings.
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Same results for me (max f4) on that same lens, using the Brevis. I've gotten to the point where I don't take the adapter off my HVX. Trying to maintain focus working between f1.8 and f4 is a bit too demanding for me, though it certainly develops those focus pulling skills.
 
IRRC, Dennis echoed the same thing about the Brevis. By not putting the ND filters in front of the lens, the images will be hazy or something like that because of the way the light interacts with the CF diffusers.
 
I'd love to see some evidence of that then. Because I've heard this theory proposed, and it makes no sense whatsoever from a perspective of optics or from experience. But it keeps cropping up, so I tested it by using an adapter and a normal amount of light, and then increasing the light level by 256x as much and compensating by using ND filters in the camera, and the results were identical. There is no effect on the ground glass, and the whole concept of a ground glass being hazy or overloaded with light is just silly. It makes no sense.

If someone can prove this, let's see it. 'Cause otherwise I'm calling this either an urban legend, or someone not knowing what they're talking about, or maybe someone had a dirty internal ND filter on their camera and came up with this silly theory as a way to try to explain it.

But you cannot haze or overload a ground glass with light. The whole concept makes no sense.
 
I've never seen the hazing or overloading effect either; ND filters out front is just my personal preference when hitting the max 'operating' aperture of the 35mm lens before resorting to any in-camera adjustments. In this case, I'm referring to vignetting and GG grain.

With the Extreme, my quick tests initially indicate I can stop down to about f8 or maybe f11 without objectionable graininess to me, but then I have to zoom in more to eliminate/reduce the increased vignetting. I still need to perform more critical tests in a variety of conditions before determining what my own final 'operating' range of settings are with the adapter.

BTW, the lively thread that Chan is referring to is here: http://dvinfo.net/conf/showthread.php?t=101051 for those that are interested.
 
I will give it a try when my Letus comes (Fedex just called:-Happy(DBG): to confirm the shipment arrival).

I did a test (once) with the Brevis using the CFL1 and could not tell the difference in terms of sharpness but my subject was partially shaded (but the sunlight was pretty strong though).

Does image haze refers to wash out images?
 
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