Welcome to our community

Be a part of something great, join today!

Register 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 :)

Helium Sensor Smearing

Aaron Lochert said:
Is your monitor calibrated? I can't see smearing on that clip until I do something pretty crazy to the black point.
Click to expand...

Yes, I saw the smear on the RED monitor and then my computer monitors as well just make sure I wasn't going crazy.
 
Corey Robson said:
Can't find any posts on this but does anyone know if Gemini is less prone to smear than Helium?
Click to expand...

I own both, and a huge reason I got the Gemini was I shoot in some very extreme low light conditions, I have not seen this issue with Gemini so far, I have seen in on my epic, usually in low light in a greenish lit place. I thought it was called banding though? who knows lol

steve
 
Steve DiMaggio said:
I own both, and a huge reason I got the Gemini was I shoot in some very extreme low light conditions, I have not seen this issue with Gemini so far, I have seen in on my epic, usually in low light in a greenish lit place. I thought it was called banding though? who knows lol

steve
Click to expand...

Thanks Steve good to know, much appreciated. I have two more questions for you if you have time. I read somewhere here that you like the STHL OLPF on Gemini; do you think STHL on Gemini in standard mode is more sensitive / less noisy than Helium with STD OLPF at the same ISO? Lastly, how do you like the color on Gemini with STHL vs STD on Helium?
 
Corey Robson said:
Thanks Steve good to know, much appreciated. I have two more questions for you if you have time. I read somewhere here that you like the STHL OLPF on Gemini; do you think STHL on Gemini in standard mode is more sensitive / less noisy than Helium with STD OLPF at the same ISO? Lastly, how do you like the color on Gemini with STHL vs STD on Helium?
Click to expand...

so I don't know if it's a mind thing with the exposure ect as I don't usually shoot this camera myself until later in the day (I do wedding films and use my 8K for prep) but I did notice when I switched to the STH that my other shooters were exposing better, there are a variety of factors at play there for sure as they were shooting a scarlet-w now relegated to c cam duty and way less sensitive than the Helium sensor. When you see those skin tones with a modern lens (milvus for second shooter) it's awesome. I do think I am sacrificing with the STH when I shoot low light though, so if I was only to use this camera for candle light dance floor I would go standard but the trade off the those clean skin tones is worth it.

On my epic-w I shoot alot of my skin tone stuff (i.e. make up macro shots) with a leica macro and black magic 1/8 filter at 60/60 STD and there is always a little bit of a green tint I have to correct for, but beyond that the Gemini blows the 8K out of the water in low light mode, it really is insane! In a controlled environment I would personally go 8K std considering the new weapon class whatver thingy, but if you need an all in one, Gemini for sure. I was even considering switching all 3 cams to Gemini, but I have settled on scarlet-w to gemini, Epic-w to new body board thingy and will do the the free cross grade on my existing gemini.

Yes I do think the standard mode is more sensitive on Gemini but the 8K is cleaner for sure, the resolution on the 8K for my purposes can't be matched

steve
 
Steve DiMaggio said:
so I don't know if it's a mind thing with the exposure ect as I don't usually shoot this camera myself until later in the day (I do wedding films and use my 8K for prep) but I did notice when I switched to the STH that my other shooters were exposing better, there are a variety of factors at play there for sure as they were shooting a scarlet-w now relegated to c cam duty and way less sensitive than the Helium sensor. When you see those skin tones with a modern lens (milvus for second shooter) it's awesome. I do think I am sacrificing with the STH when I shoot low light though, so if I was only to use this camera for candle light dance floor I would go standard but the trade off the those clean skin tones is worth it.

On my epic-w I shoot alot of my skin tone stuff (i.e. make up macro shots) with a leica macro and black magic 1/8 filter at 60/60 STD and there is always a little bit of a green tint I have to correct for, but beyond that the Gemini blows the 8K out of the water in low light mode, it really is insane! In a controlled environment I would personally go 8K std considering the new weapon class whatver thingy, but if you need an all in one, Gemini for sure. I was even considering switching all 3 cams to Gemini, but I have settled on scarlet-w to gemini, Epic-w to new body board thingy and will do the the free cross grade on my existing gemini.

Yes I do think the standard mode is more sensitive on Gemini but the 8K is cleaner for sure, the resolution on the 8K for my purposes can't be matched

steve
Click to expand...

Thanks for your time Steve, lots of great info. Big fan of the 1/8 HBM also. Will likely switch over to Gemini on my cams.
 
Corey Robson said:
Thanks for your time Steve, lots of great info. Big fan of the 1/8 HBM also. Will likely switch over to Gemini on my cams.
Click to expand...

if you want any comparisons shot real quick let me know, I am off the for the next 2 weeks besides a sub thingy, I totally can take some quick stuff and drop box it, just pm me, I have all olpfs and 3 different sensors

steve
 
Steve DiMaggio said:
if you want any comparisons shot real quick let me know, I am off the for the next 2 weeks besides a sub thingy, I totally can take some quick stuff and drop box it, just pm me, I have all olpfs and 3 different sensors

steve
Click to expand...

Very kind of you but TBH I'm prepping now and wouldn't be able to dig into them anytime soon anyway. No Reds for me until Oct. or later. Thanks Steve.
 
I've seen CMOS smear on all REDs except M/MX ... Even the Monstro has it: https://www.youtube.com/watch?v=_laH7tmxbD8

Although, not nearly as bad as the Helium and some would say Dragon as well.

You almost have to underexpose for it not to be there, it still is, but then it's pixel peeping. Either way it's still an annoyance.
 
David J. Buchanan said:
I've seen CMOS smear on all REDs except M/MX ... Even the Monstro has it: https://www.youtube.com/watch?v=_laH7tmxbD8

Although, not nearly as bad as the Helium and some would say Dragon as well.

You almost have to underexpose for it not to be there, it still is, but then it's pixel peeping. Either way it's still an annoyance.
Click to expand...

I'm am seeing this also. Its really signigicant @800-1280 when light coming in hot and bouncing off of certain surfaces in front of camera. I only noticed it on the NEW ISO Calibration
 
Brandon Obey said:
I'm am seeing this also. Its really signigicant @800-1280 when light coming in hot and bouncing off of certain surfaces in front of camera. I only noticed it on the NEW ISO Calibration
Click to expand...

To me, the smears look like an apparent change in the noise floor when there are bright pixels in the same row. So, the brighter you push the image, the more of the noise floor you're revealing. And that's exactly what the new ISO calibration did. To have the same results as you did before, pull the ISO down one stop.
 
Aaron Lochert said:
To me, the smears look like an apparent change in the noise floor when there are bright pixels in the same row. So, the brighter you push the image, the more of the noise floor you're revealing. And that's exactly what the new ISO calibration did. To have the same results as you did before, pull the ISO down one stop.
Click to expand...

Interesting. Did RED ever clear up this issue in the new firmware or is even possible to clear up with firmware?
 
Brandon Obey said:
Interesting. Did RED ever clear up this issue in the new firmware or is even possible to clear up with firmware?
Click to expand...

I'm in talks with tech support as we speak. They're looking into it, but also saying it's apart of every CMOS sensor, however, I still argue that I've never seen it on any cameras besides RED (excluding the M/MX) and Canon C300 MK II (only that specific model, and no other Canon)
 
Isn't this what happens when you're trying to sell 13-14 stop sensors as 18 stop sensors?

And it's not only RED. They probably started it, but now it's out there and a manufacturer can't market 14 stops anymore.
 
AndreeMarkefors said:
Isn't this what happens when you're trying to sell 13-14 stop sensors as 18 stop sensors?

And it's not only RED. They probably started it, but now it's out there and a manufacturer can't market 14 stops anymore.
Click to expand...

RED is definitely 14 stops max. Haven't used the Monstro yet, but I assume it's the same.
 
David J. Buchanan said:
I'm in talks with tech support as we speak. They're looking into it, but also saying it's apart of every CMOS sensor, however, I still argue that I've never seen it on any cameras besides RED (excluding the M/MX) and Canon C300 MK II (only that specific model, and no other Canon)
Click to expand...

I've seen it on other cameras including Alexa. I haven't shot much RED lately, but it does seem to be something that is more easily triggered on RED cameras. My half remembered explanation from an engineer was that once the pixels are full and go into overexposure there's a kind of "overflow" into adjacent pixels which can show up in darker areas of the image as the sensor is clocked out. This is something that's fundamental to the sensor design.

JB
 
Yup, seen it on Alexa as well.

(highly pushed Xyla chart, not representative of any sort of actual, usable image)
41713402365_8ff078e583_b.jpg


That said, they managed customer expectations by marketing 14 and letting people realize those extra stops were just bonus stops -- not to be counted on.
 
Some Weapon Dragon Xyla chart, also highly pushed.

feNKENm.jpg


Can't read what's in the "box", but something's there for sure. And here's what:

M8s1t27.jpg


That's with some light from the side. :smile5:
 
This is bigger than XYLA charts obviously. The CMOS smear is in normal footage guys. Let's avoid the obvious and accept what's real. The examples in this thread already prove that. Now show me examples of Alexa images where the exposure is where it needs to be yet you still see smear (maybe a little under or over even). I can show examples of Dragon vs Alexa footage where there is smear on the Dragon and not on Alex. Case in point: https://vimeo.com/135498367 -- TC 5:30 ... Look at the woman's legs when the clip starts, it's not flare.
 
Last edited:
You must log in or register to reply here.
Back
Top