Official shutter/iso tests

P

Park Edwards

Veteran
Mods, feel free to delete my old thread.

I started a new thread so people would see a dedicated section to iso/shutter. I have the actual photo's of 7individual shutter speeds taken directly from a photograph. Then grabs from the video with different settings and F stop to determine what setting would yield what shutter.

Note* When changing shutter, you change iso. This is mainly to test shutter speeds and no necessarily iso. I highly recommend a regular closet light and some type of cloth to diffuse it a bit so it's not bright.
Note*
1/125 = 6 steps
1/100 = 5 steps
1/60 = 9 steps
1/50 = 11-12 steps or 2 squares
1/40 = 13 or 2.5 squares
1/30 = 16 steps
1/20 = 25/26 steps
Note* It seems to be weird closer to the end of the 2nd test how the shutter wasn't on a consistent course. This may have been something I did, by not positioning the light in the exact spot each time. This is why I highly recommend a regular closet light and not something small. Big enough to cover the whole lens and easily pressed against it so it doesn't move.
Note* My light will probably vary from yours, you may not get the same results as me.


So here are the first tests. Settings are displayed on the picture. I have another 30-40 something videos to finish up. First the actual shutters.

125.jpg
100.jpg
60.jpg
50.jpg
40.jpg
30.jpg
20.jpg
 
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Hey man, great idea to measure shutter speed changes!

Now, if we have the ammount of light that got in, the shutter speed , we can find out the iso, and maybe plot a pattern that describes how the camera behaves! Maybe shoot the oscilloscope sided with a gray chart?

Anyway, I noted, something that looks mighty interesting. In order to get 1/50 shutter you had to close your iris to F11 forcing your camera to, first go to a very high iso, and then, opening shutter. But with +/- set to -0.3, you could get comparable shutter speed from a 4-5.6 split, (you didn't test it, I know, but it's right there between the two) and the ISO is way different, no?

We should do theese tests with a lightmeter and gray chart, in order to know how much light is going in the sensor, we can then plot a table of the iso and shutter values obtained and find a way to get our desired values every time.

Nice work, man!
 
Car3o said:
how can you get in between 4-5.6?
Click to expand...

Me or you? Just set your aperture to a 4/5.6 split. The middle of the ring. I know still lenses don't have the "click", but you can manually set your aperture there if you want.

But if you're asking, how do I know it's there, well I don't. I don't know how the camera is thinking. But my point is, it's very different than the other time when you got near 1/50 in terms of noise. We could map ou every single measurable way to get there and find the cleanest. Bam, we have our master D90 setting.
 
the cleanest with the best shutter is before entering live view with the light and a poloarizer filter. it's a 1/60 shutter very bright and very clean. tomorrow i'll post the rest of the grabs from the video.
 
Could someone explain in a little more detail exactly what the still grabs are of--are they from LV videos? Are the F-stops when the AE-L was engaged. The +/- designations are EV adjustments??

Or--is this too early in the testing to make the results useable yet, and the rest of us should stand by until you figure out the technical details?

Thanks so much for doing this. With shutters determined, and knowing F-stops we can calculate ISOP and finally pull the curtain away from what this camera is doing in secret.
 
Car3o said:
the cleanest with the best shutter is before entering live view with the light and a poloarizer filter. it's a 1/60 shutter very bright and very clean. tomorrow i'll post the rest of the grabs from the video.
Click to expand...

Hi,
What do mean by "before entering live view"?
 
Ruzo said:
Hi,
What do mean by "before entering live view"?
Click to expand...

Before pressing live view button, you can also adjust the F-Stop, to say F22, then hit Live View, but if you want to change f-stop again, turn off live view, change again, press LV button again.

Basically you need to trick the D90, because we (majority of us on this forum I guess I speak for) don't like the way it interacts to light, it gives us very fast shutter speeds in very well-lit situations. We'd rather have a clean image, low ISO, and a 1/50-ish shutter speed.

So we have to put polarizing filters, things of that nature to stop down the lens and keep the shutter down. I assume that's what we are talking about?

But anyways, good tests, I've been playing with D90 since October, still can't trick the D90 into a magical setting, it's getting a lil frustrating! Somebody will find the magic formula.
 
bmfm, that's not a trick, that's common sense and true even with full manual controls. there's no way you can get a well exposed image at 1/50 in well lit situations without nd's. sunny 16, remember? the lowest iso is 200 and few lenses stop down to f/32 and even if they do that's probably not what you want.
 
I've been keeping a light meter with me and checking the lighting with a 1/50 shutter setting. Today, in bright sun light my handheld meter gave me a setting for 1/50 - f18 at ISO 100. In "M" mode, I set the ISO on the camera to 100 (LO) my manual 35mm f2.0 at f18 and then took a still. Shot was perfectly exposed. Then entered LV, let it adjust and then locked AE (hold). Took movie clip. Clip looked the same as still. Then I opened up the lens to f2.0 Same bright lighting. Entered LV mode, the camera adjusted and then locked AE(hold) took clip. It looked the same as the still shot at f18. I looked at my handheld light meter scale and the shutter speed for f2.0 was slightly above 1/4000 at ISO 100.

Was the clip actual shot at 1/4000?

Also, with automatic lenses "only", is shutter priority mode settings for real after lockingAE and entering LV?

EDIT: LV exposure control was set at -0.3
 
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I'll try to explain this as best as possible. Not a lot of people are catching on and it's partially due to some misguided information when this camera first came out.

If you ARE NOT in LIVE VIEW before engaging, it DOES NOT matter what Fstop you have your lens at BEFORE engaging LIVE VIEW. Closing the lens down F22 and locking the AE will yield the same results if you had it at 1.4 and locking the AE when you turn live view on. It's the amount of light the camera sees once you engage LIVE VIEW that will determine your shutter/iso. The +/- or minus values do nothing PRIOR to entering LIVE VIEW as well. Only when you have the LIVE VIEW on does the +/- matter.
 
hepabst said:
I've been keeping a light meter with me and checking the lighting with a 1/50 shutter setting. Today, in bright sun light my handheld meter gave me a setting for 1/50 - f18 at ISO 100. In "M" mode, I set the ISO on the camera to 100 (LO) my manual 35mm f2.0 at f18 and then took a still. Shot was perfectly exposed. Then entered LV, let it adjust and then locked AE (hold). Took movie clip. Clip looked the same as still. Then I opened up the lens to f2.0 Same bright lighting. Entered LV mode, the camera adjusted and then locked AE(hold) took clip. It looked the same as the still shot at f18. I looked at my handheld light meter scale and the shutter speed for f2.0 was slightly above 1/4000 at ISO 100.

Was the clip actual shot at 1/4000?

Also, with automatic lenses "only", is shutter priority mode settings for real after lockingAE and entering LV?

EDIT: LV exposure control was set at -0.3
Click to expand...


Yes, most likely shot at really high shutter due the bright sunlight. If you had pointed it at an even surface of light or a wall in the shade before entering LIVE VIEW you would of had a slower shutter.
 
OK, so in bright sunlight high f-stops use lower shutter speeds and low f-stops use higher speeds. Then if I want to use a shallow DOF with say a manual 50mm 1.4 at f1.4 in the bright sunlight the shot will be choppy due to the high shutter speed. Will adding motion blur in post smooth out the clip? How are you all handling this situation?
 
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