Welcome to our community

Be a part of something great, join today!

Log in
  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Noise on the low end but even worse scary megenta lines

Status
Not open for further replies.
This is also why the Xyla chart is shaped like a Xylophone so you can see when this is occurring. (in case you were wondering why the shape of the chart!)
Graeme
 
Graeme Nattress said:
This is also why the Xyla chart is shaped like a Xylophone so you can see when this is occurring. (in case you were wondering why the shape of the chart!)
Graeme
Click to expand...

Nice point.

Also, Graeme, are you releasing any photos from your new firmware today?

;)
 
Jarred Land said:
Gavin and Rob are correct.. this is a relatively normal CMOS thing.. kinda like the black sun dot all cameras used to have ( i think some cameas from other manufacturers still do ) its been there since the R1 since we do use CMOS technology like almost everyone else. If you take a small source highly clipped a bunch of stops against almost black and it crosses the edge of the frame or just off the edge of frame ( most cases ) you will see what looks like a streak. People call this the "phantom blinds" effect because the easiest way to replicate this is to open slit blinds into daylight in a pitch dark room. Of course you will see this at higher ISOs, and most post houses have developed a post fix from dealing with it over the years from many cameras. Its a silicon thing.

The company that makes the dynamic range charts we use actually have added a little flag that goes over the clipping square now, because if your shooting a CMOS camera and you get that flare it can actually trick you into thinking you have more DR... since the streak replicates the shape of the highlight and lifts everything with it.
Click to expand...

Thanks for the explanation Jarred. Does this mean there's going to be a calibration for this? I know I've shot into fluro sources at 640 ISO on Epic and not gotten this artifact. We just started this shaping doc and I have some old stuff I shot on Epic and it's not present. In theory this would be present if you were shooting in a dark room into kinos, correct? Just wondering what to do in situations where I'm shooting into kinos.

@Jan Reiff - The open street shot is on a Zeiss ZE 35mm 1.4 at 1.4. I was out testing the low light on Dragon. Which has noise, but really does work much better than Epic when you downsample to 4k or 2k.
 
Graeme Nattress said:
This is also why the Xyla chart is shaped like a Xylophone so you can see when this is occurring. (in case you were wondering why the shape of the chart!)
Graeme
Click to expand...

Hi Graeme, How is the new firmware coming along? Might it be out soon? I have a very dark, high iso shoot next week, that I would love to have it for.

Thanks much!
Rich
 
Thanks, Jeremy. I shot that a few months back soon after my Dragon had arrived, so it was the old OLPF. Used a combo of the GL Optics 18-35mm and K-35 primes, which is where most of the flare comes from. You will notice the OLPF flare when I was shooting at night into the car's headlights, and that's a situation that I will test out when my Dragon arrives back from Red with the new OLPF. I'd like to see original vs new OLPF at both ISO 800 and 1600, shooting into car headlights with a small unit for fill, that way one can easily see both the noise and flare differences.
 
Charles Bergquist said:
View attachment 53702

View attachment 53703

R3D Download - https://dl.dropboxusercontent.com/u/161718/A005_C042_0327D8.0000029F.R3D

This is the same place a year earlier shot with Epic MX, I did not see any of the magenta artifacting when shooting similar angles.
Click to expand...

It doesn't happen all the time... a certain combination of things need to happen just right ( or just wrong depending on how you look at it ) It did happen on Epic MX... and Epic M, and R1 and it happens on the other guys cameras as well.

It is hard to guess but the shots above from last year it might not have the right combination of dark enough dark right next to super clipped to happen.

Calibration isnt going to fix that... its a hardware thing that im sure will be fixed in a few sensor generations down the road.
 
Jarred Land said:
It doesn't happen all the time... a certain combination of things need to happen just right ( or just wrong depending on how you look at it ) It did happen on Epic MX... and Epic M, and R1 and it happens on the other guys cameras as well.

It is hard to guess but the shots above from last year it might not have the right combination of dark enough dark right next to super clipped to happen.

Calibration isnt going to fix that... its a hardware thing that im sure will be fixed in a few sensor generations down the road.
Click to expand...

Thanks for the response Jarred. Owner response is well beyond the call of duty. However, it's on a lot of shots now, which I've never seen on my Epic-X. There was always a subtle gate flare on Epic that was similar, frame edged, but that was more faint and white. I know you guys have bigger fish to fry, but it is more pronounced with Dragon compared to Epic. I knew that Epic pretty well and shot it a lot and never had the magenta lines. Neither here nor there since it's the sensor tech at the moment.

My concern is shooting studio stuff in dark environments into a single or bank of kinos where they will clip out.
 
Julio Quintana said:
I think Jarred said that Graeme was going to post some images of the new calibration yesterday? I didn't see them so maybe they're still working on it.
Click to expand...

Graeme is sorting out all the images now... We added a Epic MX to the mix at the last moment for the comparison as a few people began to think that the Epic has more dynamic range then the Dragon which is a bit crazy... Not to take away Epic-MX's thunder but with the new OLPF Dragon has a touch more in the low end and almost 3 whole stops more in the highlights. With Graeme's new calibration the big difference in the low end is the red cast in the noise is gone even at ASA 12800, which never used to really bother me but now looking at the Dynamic range charts side by side it is a pretty amazing the difference.
 
Jarred Land said:
Graeme is sorting out all the images now... We added a Epic MX to the mix at the last moment for the comparison as a few people began to think that the Epic has more dynamic range then the Dragon which is a bit crazy... Not to take away Epic-MX's thunder but with the new OLPF Dragon has a touch more in the low end and almost 3 whole stops more in the highlights. With Graeme's new calibration the big difference in the low end is the red cast in the noise is gone even at ASA 12800, which never used to really bother me but now looking at the Dynamic range charts side by side it is a pretty amazing the difference.
Click to expand...

great guys;)
 
Engineering is a game of trade-offs - strength vs weight, sensitivity vs noise, etc. As newer sensor tech like the Dragon propagates into our industry I believe we will keep discovering more and more things like this. For the sake of discussion lets say that the MX had the same propensity to create odd row artifacts but they were subtle enough to escape notice when they were mixed in with other things like photon shot noise, FPN, etc. Perhaps Dragon's particular physical construction opened the window (sic) for a few more angles to produce this artifact. Perhaps the greater S/N ratio makes a higher percentage of these kind of artifacts obvious.

IAC, lets not forget why matte box eyebrows, "lenser" flags and such have been used for years to block light sources that created unwanted issues. With modern lens coatings the number of situations that require you to block point sources to kill optical flares is far less. So instead of the expectation being that you need to do something like rig a flag or suffer the consequences, we now expect to only have to do that in the most extreme situations. Like "gate flare" and other examples of light getting where you don't want it (internal reflections in particular) there are times you may want to make a slight change in position or use a flag.

CMOS sensors with Bayer CFAs have achieved tremendous performance levels over the last decade, but like any other device that turns photons into voltages there is a point where discriminating between environmental EMF and coherent photon information gets problematic. The design and construction of OLPFs is another delicate balance from an engineering standpoint and as Phil notes, putting a glass sandwich in the optical path is opening the door to a number of issues. Sadly, AFAIK, there is no practical alternative to the OLPF to control aliasing on high resolution Bayer CFAs - particularly in motion applications.

As a sidebar, I am a big proponent of using lenses with high telecentricity to get fewer artifacts with CMOS/Bayer/OLPF imaging devices. YMMV.

Cheers - #19
 
I already received 3 emails from customers asking to send their camera in for the new calibration... You don't need to send your camera back , The Calibration Graeme is getting ready to release is not a hardware calibration, it is a downloadable firmware calibration. When the new build is ready you just download the firmware and then do a new blackshade like normal.
 
Jarred Land said:
I already received 3 emails from customers asking to send their camera in for the new calibration... You don't need to send your camera back , The Calibration Graeme is getting ready to release is not a hardware calibration, it is a downloadable firmware calibration. When the new build is ready you just download the firmware and then do a new blackshade like normal.
Click to expand...

Chief,
do you think we can have it by the end of the week :)
 
Status
Not open for further replies.
Back
Top