Understanding and Optimizing the Nikon D90 D-Movie Mode Image

Kholi said:
Fourth post updated with some thoughts. D90 Users try this and tell me what you get.
Click to expand...


OK, I haven't played with this yet but I see an issue.

The D90 doesn't "know" what the aperture is on an AI (fully manual) lens. Some Nikons mate with that funny metal foot on the lens, but the D90 (and lesser cameras) don't. So the values you are estimating are based entirely upon the amount of light entering the camera for you at those apertures. This will obviously vary depending on the lighting and surface.

I think it would be helpful to measure the actual amount of light... using a meter, or by metering with the camera itself off a photographic grey card. This would be a fairly simple control, and then we could work up a chart where we know a certain amount of light (Exposure Value) on that grey card equals a certain known ISO / Shutter if we enter LV with that grey card filling the frame. Removing lighting and surface variables should = consistancy.

ISO could, maybe, be gaged by measuring the noise in a video still and comparing it to the noise in a small low quality jpg taken at known ISO... again all of the grey card.

Speed could be measured with the tv trick mentioned in the mother of all threads.

I'll see if I can play with this some later tonight.
 
Thebes said:
OK, I haven't played with this yet but I see an issue.

The D90 doesn't "know" what the aperture is on an AI (fully manual) lens. Some Nikons mate with that funny metal foot on the lens, but the D90 (and lesser cameras) don't. So the values you are estimating are based entirely upon the amount of light entering the camera for you at those apertures. This will obviously vary depending on the lighting and surface.

I think it would be helpful to measure the actual amount of light... using a meter, or by metering with the camera itself off a photographic grey card. This would be a fairly simple control, and then we could work up a chart where we know a certain amount of light (Exposure Value) on that grey card equals a certain known ISO / Shutter if we enter LV with that grey card filling the frame. Removing lighting and surface variables should = consistancy.

ISO could, maybe, be gaged by measuring the noise in a video still and comparing it to the noise in a small low quality jpg taken at known ISO... again all of the grey card.

Speed could be measured with the tv trick mentioned in the mother of all threads.

I'll see if I can play with this some later tonight.
Click to expand...

Hey Thebes,

The aperture's relationship to the d90 is only important to the user in getting the ISO and Shutter to a desired place. The d90 and the Aperture of a manual lens doesn't matter, correct.

If someone has the tools to measure that would be great. I'm puttin' the theory and info out there, but I do not own the proper tools to actually measure down to the bit. I think you're right in line with what I'm thinking, though, and a Grey Card (or grey Card(s)) would be best.

Everything I'm doing is by eye.

Wish I could help more! :D If you could drop the information for me I'll put your findings at the beginning of the thread.
 
You`ll get your light with card no.1,that gives you Iso200 inside.Then you`ll take card no.1 in daylight,and you`ll find out different values.

Camera does not have a reference on the grey card.
 
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so...is shutter speed directly related with Iso? Can we get just longer exposure times, without lots of grain?
 
Confused?

Confused?

I can't seem to get the AE-L to lock. I hold it down and it stays locked until I let it go. I have held it for various times, no luck. I am in manual mode (M). Anything I am doing wrong? I try to turn on LIVE MODE with the AE-L held down and nothing as well. It always just turns off when I left go.

Hmmmm.
 
shinyrobot said:
I can't seem to get the AE-L to lock. I hold it down and it stays locked until I let it go. I have held it for various times, no luck. I am in manual mode (M). Anything I am doing wrong? I try to turn on LIVE MODE with the AE-L held down and nothing as well. It always just turns off when I left go.

Hmmmm.
Click to expand...

Tip Kholi :Drogar-Smoke(DBG):
 
Menu > Custom Settings (Pencil Icon) > f (controls) >> Assign AE-L/AF-L Button > Ae lock (hold) > Ok

I'll update the post to outline this as well.
 
Kholi said:
Menu > Custom Settings (Pencil Icon) > f (controls) >> Assign AE-L/AF-L Button > Ae lock (hold) > Ok

I'll update the post to outline this as well.
Click to expand...

Now everyone will know how to lock their camera:-Laugh(DBG):
 
Not sure if this has been asked yet....

Do you have to keep the LCD on the back on while shooting video? I know the video uses Liveview to record the image but can you turn it off and just use the viewfinder for video?
 
Do you have to keep the LCD on the back on while shooting video? I know the video uses Liveview to record the image but can you turn it off and just use the viewfinder for video?
Click to expand...

It only records with LCD (Liveview) on.
 
Wes, you cannot use the viewfinder as the shutter is open the whole time you are filming. Thus the LCD is the only way of seeing what you are recording - hence it is on the whole time.
 
Kholi said:
Menu > Custom Settings (Pencil Icon) > f (controls) >> Assign AE-L/AF-L Button > Ae lock (hold) > Ok

I'll update the post to outline this as well.
Click to expand...
So does that mean that you have to keep the lock button held for the entire shot duration? Or just when you press the record button (Sorry if this has been asked before)
 
Spybreaka said:
Wes, you cannot use the viewfinder as the shutter is open the whole time you are filming. Thus the LCD is the only way of seeing what you are recording - hence it is on the whole time.
Click to expand...

yeah should have thought about that. This whole video slr thing still has me weirded out. Cant decide whether to get one or not.
 
Made an interesting d90 observation... everyone probably already knew this, but... you can move the red box on the LCD around, and it will auto expose to whatever is in the box.
 
I didn't know that. But given how jerky the auto exposure is, it doesn't seem very useful.

I made a D90 observation too, last night while looking at a Pre-AI lens which I thought was AI'd soley because it fit without binding. Well, it wasn't AI'd, and it did bind, very very slightly on a tab on the outside of the lens mount. Nothing was broken, and I think the lens could probably be used without damaging the camera... which shouldn't be the case... but I'm not going to push my luck. Beware that its easy to mount a Pre-AI lens, and if you break that tab's switch its a really bad thing.
 
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