Official shutter/iso tests

How many ND filters can be used before they effect the shot? Or should I use a step-up ring and use larger filters?
 
it depends on the focal length, but yes for wide angle step up rings are a good idea. however if you use x8 (i.e. .9) filters you only need two, so at 35mm or so and up you'll be fine.

/matt
 
I use two x8's, one on a step up mainly because it's also used on my bigger diameter lenses. With both on i use f/4 in daylight and although i haven't tested it i think i get around 1/100. It strobes but very little, i.e. film look. :-)
 
What are some recommended affordable brands for ND filters? Also, how much on average without shipping, for example?
 
Let me clarify real quick about the my use of the polarizer in the first two grabs. Matt's right, polarizers are great for outdoor, but the test shown was to add 1 more stop of light so the camera will expose to that and I'll get that 1/60 shutter and clean iso. After the camera is on, I take the polarizer off, which of course, brightens the image. This is mainly for indoor, low light stuff, not necessarily for daytime. I haven't tried that method and filmed during the day, when I find some time I'll do that. Going on 10th straight day of work here.
 
For those of us less sophisticated users, can someone walk us through the steps to get the shutter to 1/50th speed? I for one don't fully understand the screen grabs that are here.

Or--is it too early in the process to generate useable recommendations and the rest of us still need to be patient??

Thanks for the testing you are doing!
 
make sure it's dark enough, stopping down and adding nd's, then point the camera at something lit by 50 hz artificial light and wait until the rolling goes away, et voila, 1/50s. in daylight you can use the sunny 16 rule. if we assume that the iso gets set to 200 when there's enough light that means you need to use f/32 to get 1/50, with 6 stops of nd that means f/4.

/matt
 
Robert Altman said:
For those of us less sophisticated users, can someone walk us through the steps to get the shutter to 1/50th speed? I for one don't fully understand the screen grabs that are here.

Or--is it too early in the process to generate useable recommendations and the rest of us still need to be patient??

Thanks for the testing you are doing!
Click to expand...

Robert, there are two tests I demonstrated. The first test is like this. Please read carefully as I'll try to explain this as best as possible. You really need to read up on some other threads to get a grasp as to what I'm doing so you'll understand.

First test that says "light + polarizer".
You have a little closet light, a polarizer and some kind of material to diffuse the light. That what you'll need.
Turn the camera on, but don't put it in live view yet. Make sure your polarizer is on the lens or in your matte box, whatever you have, turn the closet light on, place the material over to diffuse the light. Place it in front of the lens lock your AE and engage Live View. Take off your polarizer or out of the matte box and volia, you have 1/60th shutter and clean iso. This is also with a 1.4 lens.

Second test are the ones that say "-.3 at F#". Same materials but minus the polarizer. Turn your camera on, go ahead and engage Live view. Stop your lens down to whatever stop you want. Place the closet light and diffuse material in front of the lens lock the AE and open your iris to your desire. This is where each stop represents a certain shutter speed. It's that simple.

Basically what I did is to show you what stop and what +/- value will yield what results. That's it. The first 5-6 pictures are shutter speeds from the camera taking pictures and comparing them to the videos shutter speeds.

The other tests I have are where the +/- values are set a +.7, +.3 and -.7. Each has a different effect at different F stops. I'll post those when I get a chance. But really, experiment is the key to getting results, not asking whether or not what works and what doesn't. Because in actuality, you'll most likely have different results than me.
 
Just wanted to say thanks for starting up this thread Car3o.
It's been very useful in figuring out how the video recording behaves a little more.
I've had some cleaner footage using the polarizer and getting what I assume is 1/60 shutter.
I'm curious about your tests with +/-.

Thank again for taking the time.
 
Thanks for this Car3o! One question. What if I have an AF lens with an aperture wheel? Would I set F stop to 22, AE lock, open up to F 5.6, point at source then enter LV? Would I then open up to 1.4, etc.? Gracias amigo.
 
Alan Bradley said:
Thanks for this Car3o! One question. What if I have an AF lens with an aperture wheel? Would I set F stop to 22, AE lock, open up to F 5.6, point at source then enter LV? Would I then open up to 1.4, etc.? Gracias amigo.
Click to expand...

Do you have manual control over the aperture? In order to get full manual control on AF lens, you'd have to either twist the lens so it's not on all the way and the contacts aren't touching, or you put a piece of tape over the back lens contacts. It doesn't matter what stop you have your lens at before entering LIVE VIEW. It will be the same exposure no matter what. If you're already in LIVE VIEW that's when you have to stop your lens down and lock the AE to get a certain shutter. Just try it out. But that's if you have manual control over the aperture at any given time.
 
So far, this is what has worked best for me and my lenses. I have AF lenses with the manual aperture ring. 24 mm f2.8.
So I:

set in Aperture Priority Mode
close down to F22 with aperture dial on front of D90
AE-Lock at F22 WHILE pointing at light source
then open up to F5.6 WHILE pointing at light source
enter Live View WHILE pointing at light source
then unlock aperture ring on lens and open up to F2.8

images look real clean
 
so how do you get your exposure if you don't start stopped down? locking before entering live view always gives you an extremely dark image, so you have to open up considerably to compensate. or am i missing something? i also don't quite see what locking before does that locking after doesn't, i get very clean images by stopping down to f/5.6 or so, pointing the camera at a light, locking, then opening up to taste.

/matt
 
matt, there are two ways to go about. i use a closet light covered a micro fiber cleaning cloth and polarizer. i point the light at the lens before i enter LV and lock the AE. Then turn LV on. You're right, it's real dark if there's too much light. That's why I have that cloth and polarizer. If I don't lock the AE before entering, once its in LV the +/- takes over. Whereas for some reason if you lock the AE befeore LV the camera does a fine job at exposing the light evenly with the closet light, cloth and polarizer pointed at the lens.

The latter you're speaking of is fine too, but I have found the perfect combination to be the former for my taste. Take a look at this video: It's that clean 1/60th shutter and very clean iso. Kholi first informed everyone that if you point the camera at a evenly lit source, stop the lens down and then lock AE, enter LV then open your lens up it'll give you nice clean iso/shutter, he was half right. It doesn't matter if you stop your lens or not. It exposes to your highest stop, no matter if you have the lens stopped all the way down to f22. Go ahead, try it. Your exposure will be the same at every stop. He just happen to have a perfectly lit wall, not too bright, not to dark and locked the AE and got acceptable results.

I'll have the rest of the screen grabs up tonight.

http://vimeo.com/3036920
 
how can you tell that the exposure is the same when you don't have the iso and not even the aperture for sure? all you can really say in your test is what your shutter speed is, right? the same exposure usually means the same amount of light though, and if this is what you mean it's not surprising since the camera will adjust all setting automatically to what it thinks is the correct exposure, which for the same light is always the same...

/matt
 
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