get rid of gain ( while using a 35mm adaptor ) with HV20

A

africanmarty

Well-known member
Hello all hope I get some feedback with this one,

Ok, barrys trick worked great for me ( without my 35mm adaptor ) no gain, just add more light and wala crystal clear footage without gain wich was great !

...until I wanted to get rid of gain when using my Letus 35 mm adaptor now when I put my adaptor on this is what I do :

  • Screw on letus adaptor
  • Zoom on to gg and focus sharply on gg
  • Place Nikon lens and focus the Nikon lens
  • Roll camera !!!

Now how do I do this without ANY possible gain ! As I have to zoom to focus on the gg and from what I read you must be zoomed out !! How are you fellow 35mm adaptor owners doing this trick with your adaptors to get no gain ?? I had a theory that I think works but would be happy to be proven wrong...

  • Setup 35 adaptor as explained earlier
  • Lock the exposure and aperture after pointing it to a light and keep at 0 (in other words once locked the level is left untouched at 0)
  • Add ALOT of light until the image produced by the camera is acceptable
  • Roll camera and try not to sweat too much from the heat

now would this be at f1.8 i cant tell since i had to zoom in to use my 35 mm adaptor ?? locking the exposure and aperture after pointing it to a light and keep at 0 will that lead to no gain but maybe less than f1.8 ???

hope you guys can help thanks alot

PS: is no gain the best for image quality if it can be appropratly lit ???

- Regards Marty.
 
when you use the adapter with the camcorder since you need to zoom in, the largest aperture is around f2.6 or f2.8. Also as long as I don't see any grain caused by the gain, I don't worry too much about it. When you use it during day light outdoors, there won't be any need of gain, if you are using it indoors then either you need a good lighting setting or you will need to use 1/24 shutter instead of 1/48. Then you will eliminate if not all most of the gain.
 
so are you guys saying dont worrie about all that and just add more lights until there are no grain ? and dont worrie about the cameras f stops ?
 
The question is whether your HV20 is adding gain into the video, thus creating artificial grain that you can eliminate.

The easiest way to find out is to get a miniSD card and put it in the HV20's slot. That way you can press down the "photo" button halfway, and it'll tell you what your f-stop and shutter speed are. If your shutter speed is 1/48 and your f-stop is a number from 2.0 to 8.0, then you're not getting any artificial grain. But if your f-stop is a number smaller than 2.0, there's a good chance the camera's adding gain. That's a problem, that makes your footage grainy and noisy, and the only way to avoid it is to brighten up your images so that it doesn't need to add gain.
 
Did you know that 'Spotlight' Mode doesn't allow any gain in and goes only as low as 1/50 shutter, even on 25p?

The only cost is auto wb which is annoying and no colour profile..... :S it's a toss up....If you shoot auto normally then its the perfect mode because you can guarantee no gain!!!
 
I came across the same issue not too long ago, and this is what i did:

I'm assuming you read/watched the tutorials on how to get rid of grain... good.

Put on the Letus (or brevis or whatever), zoom the camera out all the way. Now you can see the GG fully in a little window or whatever. Now point the camera at a light bright enough to get the aperture to about 4.4. I use my iphone screen and just adjust the brightness to the appropriate level. Lock the exposure at this amount, and then adjust the exposure all the way to 1.8.

Now just zoom in and focus. The aperture will close a little because it has to, but only to about 2.4 or so (can't remember the exact numbers). I'm pretty sure doing this keeps it at the brightest image possible (through an adapter) without any gain.

That's my technique anyway... interested if there are others.

Hope this helps...
 
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