I think...

The original trick was done with a cell phone for locking HV20 iris. They put a blank white picture in the phone then display it so the phone lcd was completely white. It was just enough to put the iris in a good middle range. They didn't have to worry where the shutter was because you can set the shutter manually on a HV20.

The relationship between the light and the beginning f-stop is what's important. The more light you let in before locking exposure the lower the sensitivity, less noise.
 
Christmas Eve I played around with my D90 and the 50/1.4 lens. Usually I point the camera at a bright light with aperature set at 5.6, lock exposure and then open it to 1.4 at the lens and finally lock the AE.

This time I only adjusted the exposure compensation to + values and the higher I went the more light I got. Finally without locking AE the camera stayed locked. It seamed to somehow have come to it limits regarding shutter speed. And as a bonus I didn't get any rolling 50hz issues.
 
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Car3o said:
none from what i have experienced
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well, there's no magic to the trick, and if you use any method whatsoever to decrease the iso/gain you will lose low light sensitivity by definition. not that it matters though, quite the contrary, a dark scene is supposed to be dark.

/matt
 
Remember tricking down the shutter/iso is like using slower speed film(less film grain), in the film world. Opening up the f-stop after locking the exposure is the same as adding more light to a slow speed film (fixed iso/asa) you get a brighter picture with the low grain/noise.

If you move the +/- you are changing the iso and/or shutter. I have a feeling that the d90 tries to stay close to a usable shutter speed i.e. 1/50 and changes the iso. You can see this with regard to the correct motion blur that 1/50 gives. In day light the shutter moves higher depending on the lighting because I notice a bit less motion blur. There are plugins that can add in motion blur in post to make it not look so mechanical.
 
man, my footage has changed substantially. it's so much brighter. instead of uploading footage i decided to upload some grabs...quicker that way. Screen cap direct from VlC player.

The first two pictures I set the aperture down to 16 and had the +/- to +2.0. Opened it up to 1.4 and it was crazy bright. Brighter than what I actually see.
Rest were stopped down to 16(I think) and the +/- was set to +1.0. Much cleaner, more natural look. Preset was set to Portrait. White balance 2700k.

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I used the light from the link below. Although it's nice, I think I'm gonna stick with the incandescent light from ace hardware. It's got the nice white front to it and it doesn't have the annoying lines scrolling across the screen cause the mhz isn't crazy like LED lights are. I don't see the need to dim light any unless someone has a reason why. It's does the same as the LED.

http://www.sylvania.com/ConsumerProducts/AutomotiveLighting/Products/Dotitlights/

I bought mine from walmart setting me back a whopping 7bux
 
hepabst said:
Remember tricking down the shutter/iso is like using slower speed film(less film grain), in the film world. Opening up the f-stop after locking the exposure is the same as adding more light to a slow speed film
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you get an even slower speed film if you don't stop down before locking, go figure. again there's no magic, it's just a way of setting the exposure.

/matt
 
mattsand said:
you get an even slower speed film if you don't stop down before locking, go figure. again there's no magic, it's just a way of setting the exposure.
Click to expand...

or at this stage, it is probably just way faster shutter. iso is likely already at its lowest possible here...

that's the way the new Canon works I read. (http://www.dvinfo.net/conf/canon-eo...utter-speed-1-40-1-8000-iso-workaround-2.html) It actually has shutter limits set, but when it is tricked this kind of way with the light - it does the following: 1st it goes after reducing the ISO, as soon as its down to 100, it cranks up shutter speeds, breaking even the limits set. i read that you cant for example keep iso at 200 and get fast shutter, u r always stuck with 100 iso when tricking with the light it seems... (it shows shutter/iso so people tested it)

not sure if nikon works the same way. probably similar auto-pattern...

-----

yep, dimmer would be nice to achieve different combinations and perhaps have a proven cheatsheet of iso/shutter for different dimmer settings when the light is placed in front of the lens...

i'm so surprised, with the breakthrough these DSLRs have made already, this kind of an accessory that can be just placed in front of the camera (and it can be flexible size 'sock' like RR mattebox has different diameter inserts for different lenses) with a tested cheat sheet for proven iso/shutter combinations would be really one of the top, if not #1 accessory for these DSLRs, both cannon and nikon are in need for this... it seems a very simple one to make too for anyone who has done similar tools productions... yet we have nothing packaged yet...

i guess ACE hardware light will do the trick for now. Car3o that walmart dim light would be nice (can u pls describe a bit more about that portable dimmer on it)


so far these are the attempts I found to solve similar issues, but none have come to a desirable completion:

http://www.dvxuser.com/V6/showthread.php?t=147373&highlight=d-exposure
(this guy could figure out exact shutter speeds as he goes deep into it)

http://lytecap.com/ (this one actually worked for hv20, i would even order an old version and just arrange some kind of attachment to the nikon lens, but the guy never replies)

on the other ends, no luck either:

- no hacker has surfaced to hack these for manual controls
- cannon & nikon themselves arent moving either....
 
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Car3o said:
wouldn't stopping down the lens have the same affect?
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yes, dimmer just gives more options.

but even with the constant no-dimmer light, placed at the same distance, if done at:
1. lowest f#, the camera will give lowest ISO, fastest shutter it can for the brightness of that light
2. higher than in 1. f#, the camera will give slower shutter and higher ISO# proportional to how higher is the f#.

but both brightness of the light and the f# the trick is applied and AE-Lock happens at have effect on here (i'm not including the light to lens distance as I'm assuming the light is snapped on the lenshood/mattebox)
 
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i'm getting fair enough results with it by adjusting +/- and using the stops. you can see the shutter speed change and still get a clean ISO by just holding the light in front of the lens.
 
Car3o said:
i'm getting fair enough results with it by adjusting +/- and using the stops. you can see the shutter speed change and still get a clean ISO by just holding the light in front of the lens.
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this is kinda a novice question, but just to clarify, where is this "+/-" adjusted? is it when you click play button and do +/-? i thought this is purely for the LCD and has no effect on video?
 
alexandroff said:
this is kinda a novice question, but just to clarify, where is this "+/-" adjusted? is it when you click play button and do +/-? i thought this is purely for the LCD and has no effect on video?
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It refers to the EV +/- control, located right beneath the shutter release button (at the bottom right with the +/- on it). Then you adjust with the wheel on the back of the camera. It affects the way the camera autoexposes, and seems also to have some influence on shutter speed & ISO selection.
 
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