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Park Edwards
11-08-2008, 10:35 PM
I've got the cleanest night footage of all. I played around with some settings and think...I might be onto something here. So, gimme about 20-30mins to upload. I think you might be a bit surprised how sharp and noise free it is.

mrmoe
11-08-2008, 11:14 PM
Look forward. Please summarize steps.

Park Edwards
11-08-2008, 11:49 PM
uploading footage now. if people think it's less noisy than most videos i'll post what i did/do. it was more about digging through the settings and seeing if there was any progress.

Park Edwards
11-09-2008, 12:05 AM
http://vimeo.com/2192667

Polanski
11-09-2008, 12:21 AM
Hey, that looks great... Which parameters did you set?

Lee Wilson
11-09-2008, 01:00 AM
Looks very good to my eyes.

OPHERBA
11-09-2008, 03:11 AM
Down loaded the mp4 file.

Looks very good!

Daniel Arag„o
11-09-2008, 05:07 AM
WOW,

no noise at all. and the lens is dark! how?!?! tell us, please!

thanks

Lammy
11-09-2008, 05:34 AM
I had similar results in Vivid mode and opening my 50mm to 1.4 aperture and then putting the EV down to the minus figures and then setting the lil vertical bar in the live view to minimum. Still has that slimey compression look though, like the image was resized in camera to 640x360 and then blown up.

I am interested in how you achieved the look though o_O

Matthew Bennett
11-09-2008, 06:06 AM
I think the low apparent noise is the result of a perfect storm of choosing a black crushing curve (which saves major bandwidth 'cause its just lost data), tricking the camera into a lower ISO, etc, and just the right amount of elements in the frame to create a clean looking image...
In the end though, theres no real more 'guts' or 'robustness' to the image than before...

That said, it still looks great!

bronxjragon
11-09-2008, 07:10 AM
I don't really see the big deal -- the video is extremely dark = little detail. Am I correct in saying the darker the footage is the less artifacting? And the brighter it is, the camera is trying to compensate and inevitably adds noise? I guess the way a camcorder works?

mattsand
11-09-2008, 08:29 AM
yes, the image becomes much much cleaner if you crush the blacks. i've gotten the cleanest footage with the most latitude so far by locking exposure to something bright then adjusting the aperture until the blacks just clip. i use the zoom button to check the black level noise, very handy and you see immediatey when it goes away.

Park Edwards
11-09-2008, 11:36 AM
no custom curve, not CCing or crushing the blacks. i'll post on it a little later. the preset is actually "standard" or "neutral" in camera.
Maybe the camera is itself is crushing it, but i'm not doing it.

Park Edwards
11-09-2008, 12:06 PM
Anyone know where I can find jpegs of the D90 menu? I hate typing shit out.

Park Edwards
11-09-2008, 12:21 PM
Okay, here are my settings. You will need to get "camera control 2". There is a free 30 day trial. I'd recommend it. I also posted some in camera menu stuff, cause I wasn't sure the program adjusted that for me. You'll see repeated steps from Camera Control and the in camera changes.



*NOTE* This may affect with your still shots. In fact, it probably will.

Menu/ISO sensitivity/
Iso sensitivity/3200
Iso sensitivity auto control/ON
Maximum sesnitivity/400
Minimum shutter speed/ 1/30

Long sxp. NR/ ON
Set picture contorl/ Anything mine is STANDARD
b2 Easy exposure compoensation/OFF
High ISO NR/HIGH

http://i57.photobucket.com/albums/g240/Car3o/Cam1.jpg http://i57.photobucket.com/albums/g240/Car3o/Cam2.jpg
http://i57.photobucket.com/albums/g240/Car3o/Cam3.jpg http://i57.photobucket.com/albums/g240/Car3o/Cam4.jpg
http://i57.photobucket.com/albums/g240/Car3o/Cam5.jpg

I let the camera do the walking for me. If I point it at a bright surface or area, the image gets darker. Point it at a dark area, the image gets brighter. I looked for an even surface of light so it's right in the middle and locked the exposure to my taste. You can use the zoom in button to see just how much noise is there. The one thing I kept thinking was this camera will see what I see and it doesn't...so I had to compromise. If something is too dark to the camera I let it go. That pretty much sums it up. If any of these settings don't do anything and it comes down to just one, that's cool too, don't flame me. I'm just posting what I have. I have never tried to cancel out one or the other, just kept them and shot video. So if you find something that doesn't matter, feel free to let us/me know.

OPHERBA
11-09-2008, 01:57 PM
Car3o THANK YOU!

In the tests I just did at home it is true magic!!!

Next step, how to make the picture a bit sharper....


Johnnie

ben wheatley
11-09-2008, 03:20 PM
i cant get camera pro 2 to see my d90, am i missing a trick? I am on an intel mac

mattsand
11-09-2008, 03:22 PM
no [...] crushing the blacks
well in that case they crushed themselves because they are in fact crushed. yes, the term often refers to a post processing technique but what we mean is that there's no detail in the black at all, it's at zero. it's still interesting to hear what you did of course, but i still believe that the very dark exposure is the main reason your footage looks so clean.

/matt

Park Edwards
11-09-2008, 03:34 PM
i'm okay with crushed blacks...as long as my stuff is noise free. but i get what you're saying. got some stuff i recorded earlier tonight with some fireworks going off. so, gonna post that up later tonight.

Rolly
11-09-2008, 04:26 PM
i cant get camera pro 2 to see my d90, am i missing a trick? I am on an intel mac


You need to update to version 2.3.0, version 2.0 will not see the D90

Park Edwards
11-09-2008, 06:53 PM
Rolly, thanks for pointing that out...I should've mentioned that cause it happened to me a long time ago.

so here is some new footage from today.

So, uh, I guess I can't upload another HD video. So I guess I'll have to wait. If someone wants to host it I'll send it to you.


This'll be up for the time being.
http://www.adrive.com/public/520f2cae72af675eea8be6781811e0b5dcdfe01f92c2db60f5 d233a82e4c0d01.html

mrmoe
11-09-2008, 09:03 PM
Wow Car3o!

Night shots look good. So this new Footage is from the camera settings you posted above? And what steps did you do for post?

Park Edwards
11-09-2008, 09:10 PM
Thanks mrm...both videos are from the steps I posted on the forum. I did nothing in post except add music and video transitions. That's it. I exported using .h264 codec.

mrmoe
11-09-2008, 09:54 PM
What Lens did you use?

Park Edwards
11-09-2008, 10:05 PM
a 28mm 2.8 on both.

OPHERBA
11-09-2008, 10:52 PM
Car3o,
Am I correct to assume that the use of "Nikon camera control software" is not a must since the changed parameters are all accessible on the camera menu?

Park Edwards
11-10-2008, 12:16 AM
Yes...it's just easier to follow it that way. If you can access the all the functions from in camera as I have them with Camera Control then you're good.

OPHERBA
11-10-2008, 12:47 AM
Thanks, much appreciated!

Osslund
11-10-2008, 01:47 AM
I don't understand what CC2 brings? You can adjust all those parameters in the camera? Am I missing something?

Park Edwards
11-10-2008, 10:10 AM
Yeah, it's just easier to use CC. Why would you want to sit there and click through 9 menu items when you can use the mouse and click thru 5 different tabs? It's up to you how you want to use this...I just showed what was easiest. Your call really.

stoiqa
11-10-2008, 11:53 AM
I had another shoot at night. Still looking for original track of the song to do a post mix...otherwise D90.
http://vimeo.com/2200577

awomias
11-10-2008, 01:12 PM
stoiQa ...just looked at your clips on Vimeo ...fantastic!! What music did you use for the Soccer Kidz?

Osslund
11-10-2008, 02:35 PM
There's one big problem with shooting in shots with to much black. The codec can go as low as 2000-3000/kbps when having massive black areas and to avoid coding blocks you have no choice but crushing that black and only let the light sources be exposed.

It's easy to adjust the camera in CC2 I'll give you that :)

BMFM FILMS
11-11-2008, 08:23 AM
editman, i didn't know the bitrate dipped like that...So it's better to crush the blacks in the video rather then try to bring it to life (more noise)?

BMFM FILMS
11-11-2008, 08:28 AM
I had another shoot at night. Still looking for original track of the song to do a post mix...otherwise D90.
http://vimeo.com/2200577

Holy shit! There were just parts in the video where you wonder, how the hell was this shot on D90?

Great camera.

stoiqa
11-11-2008, 08:02 PM
@avomias...glad someone likes it, something buried on my external hard drive.

@BMFM,it was a nice boost of crazy music and energy,D90 just blended in.

Osslund
11-12-2008, 01:36 AM
editman, i didn't know the bitrate dipped like that...So it's better to crush the blacks in the video rather then try to bring it to life (more noise)?

Well, best solution is to expose correctly. But if you have massive black areas, let them be black and crush it a little bit. There are alot that can be done in color correction with level controls so that you preserve as much detail as possible without getting to much compression artefacts.

I did a studio videoshot the other week and there was this big sign in the background, slightly blurred, with lots of blacks. I had no choice but crushing, adding sharpness and some level correction.

Park Edwards
11-12-2008, 02:00 AM
i just did some tests and it's not the camera that's crushing the blacks, it's the codec. i just exported it and all the the area's that were slightly visible from the raw avi are now just completely dark. is there a better codec to use than .h264 that won't do this? i'd post the video, or are all codecs going to do this?

Park Edwards
11-12-2008, 02:30 AM
...............

Park Edwards
11-12-2008, 02:35 AM
Scratch that...I'll make a new account on vimeo.

Park Edwards
11-12-2008, 09:49 PM
Here we go.

http://vimeo.com/2225618

Streaming does it no justice. Just d/l the original file. I like it. There is some banding, but that's expected. Other than that, I can't complain. The blacks aren't as crushed as you may think. And more importantly, no noise...using only a 28mm 2.8

Park Edwards
11-14-2008, 08:45 AM
Figured some codec issues out. Got it to work and no noise and no scrolling waves just using the AE-L. I can't complain any.

http://vimeo.com/2240599

alexandroff
12-05-2008, 10:54 PM
wow.

what codec is that and what r yr settings on that last one

Park Edwards
12-05-2008, 11:31 PM
codec is main concept h.264 and the settings in camera are:

http://www.dvxuser.com/V6/showpost.php?p=1461660&postcount=15

also check out the newest one with the 1.4 lens.

alexandroff
12-23-2008, 06:47 PM
Car3o, what is your D-lighting setting?

(if it has any effect on video, i dont think it does, but i heard here somewhere that even mic-OFF can:)

pveal
12-23-2008, 06:56 PM
Car3o, what is your D-lighting setting?



I was just going to ask the same thing. :thumbup:

Oedipax
12-23-2008, 10:13 PM
Car3o, what is your D-lighting setting?

(if it has any effect on video, i dont think it does, but i heard here somewhere that even mic-OFF can:)

What does mic-OFF do? Allocate more bitrate to just the video?

alexandroff
12-23-2008, 10:17 PM
What does mic-OFF do? Allocate more bitrate to just the video?

i dont think these things do much... (D-lighting isnt even supposed to have any effect on video, micrphone should make no difference either)

i dont think there's much logic behind these. its just some of the settings we try to manipulate with to get the d90 to play nice:) and find out the golden combination:)
--
i shot some low light footage today with the described in this forum settings...
will post soon.

Park Edwards
12-23-2008, 10:49 PM
d-lighting does nothing for video. and mic off...well probably nothing either, but seeing how it doesn't have to make room for audio, i'd hope the bitrate would go up just a hair.

alexandroff
12-24-2008, 01:08 AM
ok here's my 1st attempt at low light.

http://vimeo.com/2619170

this was my 1st time doing anything with the d90 video (1st time doing stair stepping, then realizing that Premiere CS4 doesnt see default d90 avi's properly, having to run it through another codec, etc. etc. i may have overdone a step or two or did a step wrong(on the codecs side - seems so 'jumpy' after the codecs))....

I slightly missed better focus, which emphasizes the need for a good HDMI field monitor....

this was done on a Miller DS10 tripod & head with D90 with Nikon 35mm f1.4 lens

Rick Horton
12-24-2008, 02:40 AM
I'm thinking about getting nikon lenses for mine. I'm still not sure which kind at the pawn shop will be the ones that fit. Oh, lookin good alex. I'd like to have a 1.4.

alexandroff
12-25-2008, 08:52 PM
one more: D90 in 'no-light', 85mm f1.4 nikon primes

http://vimeo.com/2633638

pveal
12-25-2008, 11:12 PM
Your footage is so low noise it's private :)

alexandroff
12-25-2008, 11:24 PM
Your footage is so low noise it's private :)

oops:) fixed

ESTEBEVERDE
12-26-2008, 12:12 AM
one more: D90 in 'no-light', 85mm f1.4 nikon primes

http://vimeo.com/2633638

Impessive

hepabst
12-26-2008, 09:21 AM
I've tried a number of combinations of the settings mentioned earlier in this thread they all produce the same amount of noise as with not using the settings. If it works I must be doing something wrong. The only thing that works well for me is the "cell phone trick". I personally don't use a cell phone but I have a small light that I trick the exposure down, lock it, then open the aperture (manual lens).

mattsand
12-26-2008, 02:31 PM
i'm fairly sure it's "just" a matter of exposing correctly. the camera tends to overexpose video, probably to keep the live view as visible as possible, which means higher iso and lifted shadows. exposing down a bit by exposing for a bright area for example means lower iso and crushed blacks, thus less noise.

/matt

alexandroff
12-26-2008, 03:07 PM
Menu/ISO sensitivity/
Iso sensitivity/3200
Iso sensitivity auto control/ON
Maximum sesnitivity/400
Minimum shutter speed/ 1/30

Long sxp. NR/ ON
Set picture contorl/ Anything mine is STANDARD
b2 Easy exposure compoensation/OFF
High ISO NR/HIGH

if i correctly understand the above settings:
- this sets the ISO top limit at 400
- minimum shutter at 1/30

.... aperture is already fully controlled on manual nikon lens.
doesnt this in a sense give one a great control over the camera except showing actual ISO/shutter numbers?

for example, with these settings, if one is to point the camera at darkness - the camera will crank ISO up to 400 (set in the settings limit... if one wants it higher/lower - just change the settings... i'm pretty sure this auto-ISO and ISO top limit thing legitimately works for video as in the examples accomplishing good low light results posted by people here) and slow down shutter to 1/30 (which is the min limit set in the settings... this one i'm not 100% sure of as this setting maybe just for the stills?)

then do an AE-L.
then point at the subject.
if overexposed, fix with ND filters.

...
same way - point at a bright area to get low ISO (or just set iso limit setting at 100 or 200), the camera will give a faster shutter depending on the brightness
then do an AE-L.
then point at the subject.

am i missing something?

Rick Horton
12-26-2008, 03:14 PM
The camera ignores all of that for video, and the ISO does whatever it wants, however HIGH it wants to go, until you lock exposure. Setting all of those parameters doesn't do anything for video mode.

Can somebody please tell me beyond a doubt if it does work?

hepabst
12-26-2008, 04:23 PM
One thing I've found is that if I hold down the +/- button and turn the back wheel when in LV mode the LCD gets darker or lighter depending on which way the wheel is turned. Is this just changing the brightness of the LCD or actually changing the exposure?

BMFM FILMS
12-26-2008, 06:04 PM
That's the exposure compensation, there's been lots of discussion about it. The other way is holding the play button and the up arrow to make it brighter. But thats about it.

hepabst
12-26-2008, 06:46 PM
Here is a short clip of my first time in low light, well first any time. I tricked the camera exposure with a light. Lens Nikon 50mm f1.4.

http://www.pabstfilms.com/clips/d90lowlighttest24p.mov

Park Edwards
12-26-2008, 07:12 PM
you show how you "trick" it with a light?

and need to see a higher rez version to get a better idea.

to all those who are questioning how i setup my camera...what you see on #15 is exactly what i do, whether or not it has any affect, who knows...but once I did all that, I had little to no noise in my shots.

hepabst
12-26-2008, 08:11 PM
Here are the untouched .avi files from the camera that made up the above clip.

http://www.pabstfilms.com/clips/d90lowlighttest-1.avi
http://www.pabstfilms.com/clips/d90lowlighttest-2.avi
http://www.pabstfilms.com/clips/d90lowlighttest-3.avi
http://www.pabstfilms.com/clips/d90lowlighttest-4.avi

I use a small battery powered closet light that I got from ACE hardware. (pic attached)

This is my process. This requires a manual lens. I used a Nikon 50mm f1.4. I set the f-stop at f8 then put camera in LV mode. Turn light on and I put it about 10 inches from lens. You will see the camera adjust down then I lock exposure. I opened up the f-stop and started shooting. That's it.

Park Edwards
12-26-2008, 08:40 PM
i wonder if there is a way to dim that light

Park Edwards
12-26-2008, 08:43 PM
just checked that out. that's good man...pretty sharp too. i have one i'm gonna try out. see what i can get

Park Edwards
12-26-2008, 08:53 PM
just tried it out...very easy, very easy to keep constant exposure...you my friend deserve an award. it takes out having to find an evenly list surface to lock down exposure. f8 is too much, pumps the gain too high, i put it at f4 and it's fantastic. i'm gonna check to see if i can put a higher watt bulb in it and play with the +/- values and maybe we can finally get accurate shutter speeds and achieve low light.

hepabst
12-26-2008, 08:55 PM
i wonder if there is a way to dim that light

I just move the light further away from the lens to dim, closer to brighten. I like using the light because it's the same amount of light every time. It makes it easy to recreate what I did.

hepabst
12-26-2008, 09:01 PM
It's not my idea. I learned how to do that with my Canon HV20 over at the HV20 forum. They should get the award.

I used f8 because my light is pretty bright. It just depends on how much light is getting into the camera as to what f-stop you start out with. It will take a bit of experimentation.

Park Edwards
12-26-2008, 09:09 PM
you deserve it for bringing it to these boards. i suppose it's going to depend on a lot of different variables....

lens, amount of light entering and what not. i'm going to keep it in the same spot and just stop down and use the +/- button to change shutter and iso.

i'd move it in closer or further if the lens didn't have the ability to stop down, and since it does, i'm just going to put it at the end of the matte box and take it from there.

thanks for showing this. i'm excited to use it now.

Park Edwards
12-26-2008, 09:10 PM
I like using the light because it's the same amount of light every time. It makes it easy to recreate what I did.

exactly!

Park Edwards
12-26-2008, 09:18 PM
you remember what picture preset was?

vivid/neutral/standard and if you adjusted the +/- any?

hepabst
12-26-2008, 09:20 PM
Standard preset, no adjustments to +/-

alexandroff
12-26-2008, 10:22 PM
this is great. its a lytecap for the d90 that never saw the light of day...
there must be some kind of simple dimmer for these lights.
once its found and connected, we can then mark certain light levels linked to f-stops and observed d90 iso/shutter

alexandroff
12-26-2008, 10:54 PM
what if we were to just use the white cap surface of that ACEHardware light stuck to the mattebox front

lit by dimmable:

http://cgi.ebay.com/Coast-V-Luxeon-Chip-Dimming-Flashlight-LL7798_W0QQitemZ330149324162QQcmdZViewItem

or

http://flashlightnews.net/forum/index.php?topic=777.0;all

alexandroff
12-26-2008, 11:53 PM
I set the f-stop at f8 then put camera in LV mode. Turn light on and I put it about 10 inches from lens. You will see the camera adjust down then I lock exposure. I opened up the f-stop and started shooting. That's it.


f8 is too much, pumps the gain too high, i put it at f4 and it's fantastic. i'm gonna check to see if i can put a higher watt bulb in it and play with the +/- values and maybe we can finally get accurate shutter speeds and achieve low light.



if that f# where Exposure was locked ends up being too high and going down to the smallest # makes it way too overexposed, apart from like Car3o said - "doing AE-L at lower f#", I came across this which could be of use:

http://www.singh-ray.com/varind.html

(2-8 stops)

Park Edwards
12-26-2008, 11:55 PM
if i had money....$340 is out of my budget.

so far playing around with this light is producing some really great results.
there is a led light at wal-mart for 7bux that you can dim 3 ways.

i'm gonna check into that tomorrow...

alexandroff
12-27-2008, 12:03 AM
there is a led light at wal-mart for 7bux that you can dim 3 ways.
i'm gonna check into that tomorrow...

awesome... lets create some kind of cheatsheet with these 3-dim-stops relative to d90 iso/shutter, with AE-L at noted F-stops...

alexandroff
12-27-2008, 12:07 AM
there is a led light at wal-mart for 7bux that you can dim 3 ways.


wouldnt happen to have a link to that light online?

mattsand
12-27-2008, 02:23 AM
i want one that flickers at 50 hz so that i can remove the lines with it too. problem is all battery powered fluorescents use high frequency ballasts. i guess i have to build my own. maybe a led and a 555 would do the trick, dimming could be done through pwm. i'll let you know.

/matt

hepabst
12-27-2008, 06:22 AM
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.

Rick Horton
12-27-2008, 06:55 AM
That is very good.
How much of the camera's ability to shoot in low light gets lost after the trick?

Osslund
12-27-2008, 08:35 AM
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.

Park Edwards
12-27-2008, 10:41 AM
That is very good.
How much of the camera's ability to shoot in low light gets lost after the trick?

none from what i have experienced

Park Edwards
12-27-2008, 10:42 AM
wouldnt happen to have a link to that light online?

nah, but i'll be sure to show what it is.

mattsand
12-27-2008, 01:41 PM
none from what i have experienced

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

hepabst
12-27-2008, 04:33 PM
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.

Park Edwards
12-28-2008, 12:01 AM
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.

http://i57.photobucket.com/albums/g240/Car3o/vlcsnap-40677.png
http://i57.photobucket.com/albums/g240/Car3o/vlcsnap-42144.png
http://i57.photobucket.com/albums/g240/Car3o/vlcsnap-42692.png
http://i57.photobucket.com/albums/g240/Car3o/vlcsnap-43213.png
http://i57.photobucket.com/albums/g240/Car3o/vlcsnap-43577.png
http://i57.photobucket.com/albums/g240/Car3o/vlcsnap-44302.png

Park Edwards
12-28-2008, 12:05 AM
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

mattsand
12-28-2008, 12:35 AM
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
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
12-28-2008, 12:38 AM
I don't see the need to dim light any unless someone has a reason why
to set different exposures for different light levels.

/matt

Park Edwards
12-28-2008, 01:20 AM
wouldn't stopping down the lens have the same affect?

alexandroff
12-28-2008, 01:31 AM
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.

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-eos-5d-mk-ii-hd/138905-total-control-over-shutter-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....

Park Edwards
12-28-2008, 01:46 AM
but my question is, why dim it when stopping down does the exact same thing? or is stopping down not dimming the light?

alexandroff
12-28-2008, 01:49 AM
wouldn't stopping down the lens have the same affect?

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)

alexandroff
12-28-2008, 01:51 AM
but my question is, why dim it when stopping down does the exact same thing? or is stopping down not dimming the light?

just more range with both f# & dimmer
but f# may just be sufficient

Park Edwards
12-28-2008, 01:55 AM
gotcha...

Park Edwards
12-28-2008, 01:56 AM
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.

alexandroff
12-28-2008, 02:03 AM
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.

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?

Oedipax
12-28-2008, 02:07 AM
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?

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.

shiny4
12-29-2008, 07:32 AM
if someone have ipod touch(3,5" lcd) can use it as light and dimmer.you can copy on you ipod white jpeg images with different IRE value.
from white 100 ire to 90-80-70 or 60.then using it to lock the exposure.
you can play also the video that is suggested to this post(http://www.dvxuser.com/V6/showthread.php?t=147373&highlight=d-exposure) to calibrated the shutter speed.
i'm waiting for nikon d90 and ipod touch.if someone want ,can do same test.

alexandroff
12-29-2008, 09:00 AM
how does one go about creating such images...
i mean i have a Adobe Fireworks where i can change color numbers, say from #FFFFFF
format for pure white...

or RGB values, but not sure how to create necessary IRE there

mattsand
12-29-2008, 09:17 AM
Ire really means nothing in this context, it refers to ntsc video levels. Although the typical conversion function between rgb and ntsc yuv is known, to create a true reference scale you need to know the gamma of the phone/ipod display as well as the contrast range, which you don't so just make a few of different brightness from 0 to 255.

shiny4
12-29-2008, 10:42 AM
yes,
if you want you can use rgb value in 8 bit scale from 0 to 255.
look here to grey scale in macbeth colorcecker card:
http://www.mambo.net/cgi-bin/TempProcessor/view/113.
middle grey in rgb is about 117-117-117.
you can create images from 117 to 240 in step that you want.
about ire values some charts are in IRE or millivolt value like this one:
http://3cp.gammadensity.com/images/color_chart_3cP_709-full.jpg

mattsand
12-29-2008, 10:50 AM
about ire values some charts are in IRE or millivolt value like this one: http://3cp.gammadensity.com/images/color_chart_3cP_709-full.jpg
yes, but when you show that on a non calibrated display the values mean nothing.

/matt

alexandroff
12-29-2008, 12:38 PM
yes,
if you want you can use rgb value in 8 bit scale from 0 to 255.
look here to grey scale in macbeth colorcecker card:
http://www.mambo.net/cgi-bin/TempProcessor/view/113.


attached is this colorchecker card recreated for iphone.
there are png images for iphone/ipod touch resolution 320x480 pixels 300dpi

lets assume:
- use full brightness, auto-brightness OFF on your devices
- put it right in front of your lens/mattebox so no other light other than iphone screen gets in

now with these... hopefully someone competent cant record approx. iso/shutter values so we have at least some kind of reference table to be the base platform.

(two files due to the site file upload limit)

Park Edwards
12-29-2008, 01:27 PM
you can probably test shutter, but how can you really test the ISO? just comparing pictures? the camera won't tell you what ISO you're recording video at, so you're just gonna have to guess.

on another note, a co-worker has a Oscilloscope and I'm post the videos of each +/- value matched with stop and a sample clip of an evenly lit space so you can see ISO...gonna be at least a days worth of work.

alexandroff
12-30-2008, 02:56 PM
you can probably test shutter, but how can you really test the ISO? just comparing pictures? the camera won't tell you what ISO you're recording video at, so you're just gonna have to guess.

yep, pure guess on the ISO part.
However, when one goes for a brightly lit object trick, I think the D90 brings the ISO down to 100 1st, before increasing shutter speed. Canon operates that way too (showing those values). so i think in this case, we're always stuck at ISO 100.
just a theory...

even if it is incorrect, there's certainly a top & bottom limit where D90 kicks in the shutter / iso adjustment and pattern for which to adjust 1st. it is not random as the camera just follows the code in its firmware to autoadjust that certain way.... cannon has these shutter limits too at which it does its predictable behavior. With the oscilloscope and solid lit object like iphone screen and universally agreed images that pattern can be traced.

Park Edwards
12-30-2008, 04:04 PM
only difference will be i won't have the iphone. so tests won't coincide with the iphone at all. but it'll help those who have the closet light.

alexandroff
12-30-2008, 04:10 PM
btw, when these +/- things are adjusted, the camera adjusts just the ISO?

Oedipax
12-30-2008, 07:26 PM
ISO and shutter, I thought.

alexandroff
12-30-2008, 07:30 PM
ISO and shutter, I thought.

i thought so too and then read this in the manual (page 90)
that Shutter in Aperture when in M mode - dont change (i know it is for stills) but anyway?

mattsand
12-31-2008, 03:07 AM
if everything that applied to stills applied to d-movie we wouldn't be having this discussion. no, the compensation only changes the target exposure value, the camera gets there the same way as always, i.e. whichever way it wants no matter what you tell it. ;-)

/matt

Uwe Lansing
01-01-2009, 09:21 AM
Another lowlight-example. This time with a lot of noise ;-).
http://www.vimeo.com/2688165
Happy New Year...

Park Edwards
01-01-2009, 12:34 PM
instead of dimming the light, i got the 3x3 cavision filter to put in my matte box and used pieces of paper to dim the light. works pretty well.