Because this pixel does not allow you to perform an optimized CDS in GS mode to cancel the kTC noise. There do exist some trainings and courses about these kind of topics ;-)
No, it was also ots available at that moment. Was also on the Vision Show at that time. But I see now, it is a new flyer with BAE template instead of Fairchild. old flyer
The sensor was indeed ready 5+ years ago, but then a broadcast company that makes cheapo wannabe cinema cameras secured exclusivity for it, so that they can deliberately cripple it - initially promising the GS mode and before shipping they cancelled the GS mode. But even in 60p RS (25% of the sensor capabilities), the performance of this sensor is pretty poor and strong FPN is visible - I believe that is due to the separate LG/HG paths and troublesome tonemapping. Later, a 120p RS gen2 camera was released, still under-utilising the sensors capabilities.
The main issue though is, that those cameras were sold almost for the list price of this sensor, and today you can get such camera for about quarter of the price of the sensor.
In GS mode, I think the noise will be very high. And there will be a large PLS. So, this GS will be useless. Just a rolling shutter sensor.
ReplyDeleteTheir spec states 5e- rms noise in GS mode
DeleteWhy the noise in GS might be high?
ReplyDeleteBecause this pixel does not allow you to perform an optimized CDS in GS mode to cancel the kTC noise. There do exist some trainings and courses about these kind of topics ;-)
DeleteProfessor, there is also the possibility to do an off-chip CDS. :)
DeleteThat is also part of that training I was referring to ;-)
DeleteThey presented this sensor in early 2015:
ReplyDeletehere
and here
What is the news now, something changed? I did see that the power then was 2.0W, now 5.0W.
The LTN4625A flyer is dated by November 2021. Maybe they decided to make this sensor an off-the-shelf product available to everybody since last month.
DeleteNo, it was also ots available at that moment. Was also on the Vision Show at that time.
DeleteBut I see now, it is a new flyer with BAE template instead of Fairchild.
old flyer
Thanks. It's interesting to compare the old and new flyers:
DeleteOld: rolling and global shutters
New: same and also global reset/rolling readout
Power consumption: old - 2W at 60fps, new - 5W at 60fps
RS noise: old - 2e- rms, new - 1.5e- rms
It appears the sensor went through some design iterations over the years
The sensor was indeed ready 5+ years ago, but then a broadcast company that makes cheapo wannabe cinema cameras secured exclusivity for it, so that they can deliberately cripple it - initially promising the GS mode and before shipping they cancelled the GS mode. But even in 60p RS (25% of the sensor capabilities), the performance of this sensor is pretty poor and strong FPN is visible - I believe that is due to the separate LG/HG paths and troublesome tonemapping. Later, a 120p RS gen2 camera was released, still under-utilising the sensors capabilities.
ReplyDeleteThe main issue though is, that those cameras were sold almost for the list price of this sensor, and today you can get such camera for about quarter of the price of the sensor.
Some things are really messed up in this world.