PDA

View Full Version : BMC and night / dark exposures



CineMac
01-18-2013, 10:47 PM
Just thought I'd throw this out there. We've heard some good thoughts from JB and Frank about exposing in daylight (zebras at 100% and close down enough to make them disappear) but I'd love to hear your thoughts about getting the cleanest (minimal noise) exposure in lowlight.

I know if you're shooting RAW then it doesn't much matter if you're at 800 ISO or 1600 ISO... so is it more of a matter of bringing some lighting to get that good exposure and then bringing everything down in Resolve?

jambredz
01-20-2013, 09:45 PM
I'd Like to hear more on this also

nickjbedford
01-20-2013, 09:52 PM
I don't really see much mystery in the "low light" thing.

If you manage a normal exposure then you'll be fine, but if you're struggling for light, unless you have the kind of lighting to light what you need (which can be minimal or a giant production), you'll end up with a noisy image.

The camera doesn't really care that you're in low light. As long as you feed it light, it'll give you a clean image. You either need more lights or a faster lens, or both.

We're kinda lucky with DSLRs that can shoot comfortably in ISO 1600 or 3200 and still produce usable results. They have much better anti-aliasing though, due to high resolution and a much larger sensor.

CineMac
01-20-2013, 10:28 PM
Yeah, makes sense. Just was wondering if there was any "secret sauce" that anyone has discovered with the BMC in low light... but anyway I started talking a bit more about settings in this thread (http://bmcuser.com/showthread.php?2487-Night-Shoot-Downtown-Dallas) with "thethingsitdoes" if anyone's interested.

Jorge De Silva
01-21-2013, 04:09 AM
I have some interesting results from 2 days shooting with the camera, lowlight in the city.
A lot of persons will become disappointed, just saying!
Not in every situations, because in another situations these things can happen ( :) !!! ) :

http://img825.imageshack.us/img825/6899/bmccnightf45.jpg

Full review soon :)

nickjbedford
01-21-2013, 04:31 AM
Looks quite good. What aperture were you at for that Jorge? Was there any exposure push after the fact?

Jorge De Silva
01-21-2013, 04:39 AM
RAW, m42 Sigma 28mm f/4.5 :)
I Love this shoot. No push, Highlight corrections only and no color grading. But the other shoots in the streets itself... i'm very worried and kinda disappointed :/ Let's see if I can do some miracle with resolve instead of Adobe Camera Raw.
One thing to remember, never trust the LCD. It's way too bright. Everything you see in raw recording means nothing almost.

nickjbedford
01-21-2013, 04:43 AM
RAW, m42 Sigma 28mm f/4.5 :)
I Love this shoot. No push, Highlight corrections only and no color grading. But the other shoots in the streets itself... i'm very worried and kinda disappointed :/ Let's see if I can do some miracle with resolve instead of Adobe Camera Raw.
One thing to remember, never trust the LCD. It's way too bright. Everything you see in raw recording means nothing almost.

Yeah it's a tricky display to shoot with sometimes. You're really at the mercy of the city when shooting at an ideal of only ASA 800, aren't you.

Jorge De Silva
01-21-2013, 04:50 AM
Yeah it's a tricky display to shoot with sometimes. You're really at the mercy of the city when shooting at an ideal of only ASA 800, aren't you.

My test of the BMCC is fully with avaiable light. Daylight and citylights. Best way to test the sensor in my prespective.
At night (here is 10.45 am), I will post one scene from a dark street. I got really bad results. :( And in the LCD screen looked cool when shooting, with enough light.
In the BTS video with my nex5n is ISO 1600 18-55 lens at f/3.5 and I had better colors, more DR and way more light. Almost like my eyes... I really dont understand... Damn LCD...

ianim8
01-21-2013, 01:01 PM
Jorge you picked an amazing scene to get that frame :)

Would love to see the video.

Jorge De Silva
01-21-2013, 03:02 PM
Jorge you picked an amazing scene to get that frame :)

Would love to see the video.

Hehehe Yeah. I have a lot more. Soon :) In about 30 min I will start the shooting of the review itself. A couple of days and I will upload :)

kevin baggott
01-21-2013, 04:41 PM
looking forward to that jorge :)
Kevin

dcloud
01-22-2013, 09:00 AM
I tend to set recording to film and display to video.
Video mode on display crushes the darks on the lcd. Otherwise, if display is on film, everything is clear and you wouldnt know if its noisy or not.

Jorge De Silva
01-22-2013, 10:48 AM
I tend to set recording to film and display to video.
Video mode on display crushes the darks on the lcd. Otherwise, if display is on film, everything is clear and you wouldnt know if its noisy or not.

Correct! And I discover that in the bad way!!! I have Completely BLACK shoots! And in the LCD I can see properly!!! Sample maybe tonight!

CineMac
01-22-2013, 10:59 AM
That "video" display option only really shows up on an external monitor right? I didn't really notice a difference on the BMC's lcd screen... I just set zebras at 100% and adjusted my exposure knowing I'd be making adjustments in resolve. I did notice that peaking was sometimes hard to see too... maybe I'm just going blind!

Jorge De Silva
01-22-2013, 11:05 AM
That "video" display option only really shows up on an external monitor right? I didn't really notice a difference on the BMC's lcd screen... I just set zebras at 100% and adjusted my exposure knowing I'd be making adjustments in resolve. I did notice that peaking was sometimes hard to see too... maybe I'm just going blind!

It changes like day for night! Try pu use Film for recording an the option film in the lcd and the video on lcd... You will see.

metaljesus
01-23-2013, 08:29 AM
I have Completely BLACK shoots! And in the LCD I can see properly!!! Sample maybe tonight!

Did you have the LCD on Film and recording on Video?

Jorge De Silva
01-23-2013, 10:57 AM
Did you have the LCD on Film and recording on Video?

Oposite. In RAW recorcding you can only use FILM gamma to record. In the preview mode you can select Video or Film gamma. I Used film gamma. Big mistake...

Jorge De Silva
01-23-2013, 03:36 PM
My example:

Here is it. This is all the available light that I had on the street (nex5n Iso1600 18-55 f/3.5):
http://img577.imageshack.us/img577/488/makingofsample01.jpg

http://img560.imageshack.us/img560/4561/makingofsample02.jpg


This is the BMCC (28mm lens at F/2.8):
http://img836.imageshack.us/img836/8141/frame000265.jpg

With 2EV more:
http://img853.imageshack.us/img853/1199/frame000265evpush.jpg

I have some shooted with a 50mm at F/1.4. Just a little bit better...

I know that for a real production Lighting is the key. But i just expect more... Next time I need faster lenses and expose more (to the right i know :) I use RAW in photograhy ;) )

CineMac
01-23-2013, 04:45 PM
@Jorge - Weird... in your behind the scenes photos it looks like there's a lot more light than is showing up in the BMC shots. I also did some low-light indoor tests where I shot at ISO 1600 that came out super dark... and when I tried to lighten them up I got a ton of grain. I'm wondering if you shoot in RAW if it really matters if you're shooting in ISO 800 vs ISO 1600, in terms of grain... I mean, if you shot in 800, could you lift your mids the same amount and get less grain...

Just thinking out loud here... might be an interesting test...

Jorge De Silva
01-23-2013, 05:00 PM
@Jorge - Weird... in your behind the scenes photos it looks like there's a lot more light than is showing up in the BMC shots. I also did some low-light indoor tests where I shot at ISO 1600 that came out super dark... and when I tried to lighten them up I got a ton of grain. I'm wondering if you shoot in RAW if it really matters if you're shooting in ISO 800 vs ISO 1600, in terms of grain... I mean, if you shot in 800, could you lift your mids the same amount and get less grain...

Just thinking out loud here... might be an interesting test...

In raw ISO means nothing in BMCC. the camera is always capturing in ISO800. In Prores and DnxHD it's a different story. Slowly I'm getting there. I'm now trying to push a lot of files above 2EV and using Neatvideo in AFX I'm getting pretty good results. Let's see...

Felix
01-24-2013, 08:27 AM
Just posted this in the official forum:

I just watched Franks lowlight test again. RAW does seem to be a lot darker than prores.
https://vimeo.com/48407841

Watch:
0:17 Min FS100 ISO 800
0:54 Min BMCC Proes ISO 800 ( a little darker than the FS100)
2:02 Min BMCC RAW -> Really dark. More like ISO 200 compared to the FS100.

Maybe setting the screen to ISO 400 is a better idea when recording RAW, and when you need ISO 1600 use Prores...

Jorge De Silva
01-24-2013, 08:31 AM
I have seen :) I already replied Read what JB told me. ;)

I will create my own thread with all the samples, daylight too, prores etc... It's better.

Frank Glencairn
01-24-2013, 09:06 AM
This is, how good it gets (or at least, how good I'm able to make it)

2074

The blacks of your Red and Green channel are clipped beyond repair.
Not much I can do here. I have no Idea why my lowlight shots look so much cleaner.

Just going out on a limb, though I know (or at least think) the ISO setting doesn't mean anything in raw, but an you do a test at the same location with ISO set to 800.

It's just an idea I have, maybe I#m wrong - but I never shoot in anything else than 800 ISO.

Frank

dustylense
01-24-2013, 04:42 PM
frank, is that from the DNG or did you give it a go from the jpeg posted here? Jorge, is there a DNG of this scene that you can host somewhere?

Jorge De Silva
01-24-2013, 05:00 PM
frank, is that from the DNG or did you give it a go from the jpeg posted here? Jorge, is there a DNG of this scene that you can host somewhere?

Frank uses the DNG. It's hosted here: https://www.dropbox.com/s/swh9sm3ji3ydgt4/Frame000265.dng

dustylense
01-24-2013, 05:17 PM
Yeah, tough image. Just not a lot of info but here is my stab at it. (I'm sure compression will kill it here though)2079

Uploaded to my dropbox so you can download and see without forum compression: https://www.dropbox.com/s/sdk7dt6ozcbao08/Frame000265.jpg

Jorge De Silva
01-24-2013, 05:26 PM
I will explain later what has happened with my lowlight images. I'm a little bit dissapointed with the lowlight hability regarding the BMCC. You need to learn a totally new way to expose for this camera... in special, night shoots! :/

I will continue my journey here with full updates, review, samples, etc... check it! :)

-> http://www.bmcuser.com/showthread.php?2552-Blackmagic-Cinema-Camera-EF-Tests-amp-Review

Best,
JDS

dustylense
01-24-2013, 05:33 PM
Ummm, OK. For this scene I think you just didn't have adequate light for an ISO800 camera. We all know that the BMC and any raw camera benefits from exposing to the right. I've known that for years. It's nothing "totally new". Upload some DNG's to your post when you get a chance.

Jorge De Silva
01-24-2013, 05:38 PM
Ummm, OK. For this scene I think you just didn't have adequate light for an ISO800 camera. We all know that the BMC and any raw camera benefits from exposing to the right. I've known that for years. It's nothing "totally new". Upload some DNG's to your post when you get a chance.

I know, and the same settings with my nex5n I get almost double the light with my nex... I photograph for years. What seems strange to me its the LCD output...etc... I have everything configured to more light possible! Only a f/2.8 lens... cant expose more... but in lcd looked ok! ...and if I had shooted this is prores the output It would be better.. and that's strange! I go to paris in about two weeks, I will test there lowlight again with a 24mm f/1.4.

More luck next time...