4:4:4 10bit single CMOS HD project

Jason Keenan · August 3rd, 2004, 12:18 AM

The reality is that Its likely I won't get this camera. I'm just a geek so I like to learn geeky stuff. I'm looking at other cameras though so this stuff will probably apply.

Re the hex stuff, I've done a little bit of assembly in my younger days. In reality it was mainly 'disassembly' so fairly basic, but I just wanted to know what I was dealing with if I decided to have a play at a basic assembly based bayer filter. It wouldn't be very good, but hey, it's just geek fun.

As you say, I remember this discussion earlier in the thread but at the time I had no idea what it meant. Now i do, sort of. If I understand how the image is constructed, this will obviously be easier.

Cheers

Raavin ;)

Ben Syverson · August 3rd, 2004, 12:31 AM

Raavin: I totally understand. My own interest in this project is about 50% film geek, 50% computer geek. :) That's the ratio I like to maintain. I guess that adds up to 100% geek in any case. :)

Juan M. M. Fiebelkorn · August 3rd, 2004, 12:33 AM

Ben,
Do you have an aproximate ASA equivalent of the Sumix camera you got?

Obin?

Ben Syverson · August 3rd, 2004, 12:38 AM

Juan, I'd put it at between 50 and 100 ASA. It depends on whether and how you're using the LUT -- which will also affect dynamic range. But at 8 bit, your choices as to how to use the range are more limited.

There are definitely times when it seems equivilent to 100 ASA film (which I've shot a ton of), but with certain settings/light levels, it feels a full stop slower.

Please note this is a totally emotional appraisal, because there's no good way to rate a CMOS/CCD sensor in terms of ASA. These sensors are linear, whereas film has a distinctive "S" curve response to light. So an ASA/ISO rating is only a small part of the picture.

Ben Syverson · August 3rd, 2004, 01:20 AM

I just got my 10mm Schneider Cinegon f1.8 lens in the mail today... This is a gorgeous lens. It's only single coated (multicoating is overrated), but it kicks the pants off of the multicoated Computar 8mm I've been using, and it's nearly as wide. It's sharp, high contrast, and has none of the barrel distortion I feared it might exhibit. I think this will become my main shooting lens, with the 8mm used for extra wide shots, the 25mm Angenieux for close ups, and the 75mm Angenieux for telephoto shots. God I love primes. The best thing about this whole HD camera setup is getting to work with primes again, and only using zooms when I want to.

I'm anxious for Sumix to come out with their new software -- I'm ready to shoot!

Juan M. M. Fiebelkorn · August 3rd, 2004, 01:24 AM

Ben,
Do you agree with the 640 ASA rating given to the DVX100?
(I ask this because I want to make a correlation between you camera and DVX to get myself a better idea about sensitivity)

Ben Syverson · August 3rd, 2004, 01:27 AM

I haven't used the DVX100 extensively, but 640ASA is downright laughable, unless you crank the grain.

The DVX100 gives a much darker image than my GL1 at 0 gain, and I would put the GL1 at 0 gain at around 400 ASA. Shooting with the DVX100 is like shooting with about 200 ASA film in terms of the amount of light you need...

Juan M. M. Fiebelkorn · August 3rd, 2004, 01:31 AM

I compared it with a photometer, and to me that scale of 640 was right.I used it everyday for 6 weeks, with and without Mini35 adapter and Zeiss Primes F1.2 .
All the movie was shot at night with only the light coming from sodium street lights and in some ocassion the camera was more sensitive than my own eyes...
I must accept that what you get is very dependant on Gamma adjustments , pedestal etc....
I didn't use more than 0 db gain setting.

So you would say your camera is one stop less sensitive than a DVX100?

Ben Syverson · August 3rd, 2004, 01:42 AM

Juan, I haven't played with the DVX100 for months, so I can't give you a hard and fast comparison, but I would guess that SMX-150c is anywhere from a stop to 2.5 stops slower than the DVX100... Maybe more... But again, I'm not sure stop math is the way to think about the differences.

For example, once the 10bit software is available, it may be possible to shoot 100% linear, which looks dark, and then apply a gamma curve in post to bring the image out and make it look "normal." If we can do that, it will effectively make the camera a stop to two stops faster, because we'll need less than half as much light to get a good image.

But again, this is all non-linear for now, so it's rather nebulous. I'm witholding judgement until I see what an extra two bits (four times as many gray values) can get us...

Juan M. M. Fiebelkorn · August 3rd, 2004, 01:44 AM

Thank you Ben.
Very usefull info.
It was just I'm too used to film terms and scales and it is the only way I can compare things :)

Wayne Morellini · August 3rd, 2004, 04:59 AM

<<<-- Originally posted by Jason Keenan :
dealing with if I decided to have a play at a basic assembly based bayer filter. It wouldn't be very good, but hey, it's just geek fun.

-->>>

Yes, please do. Rob has had very good results (performance gains) going from straight C to include inline assembler. People are so used to C (and Windows) they don't realise how much of a ball and chain it is compared to assembler.

Jason Rodriguez · August 3rd, 2004, 04:45 PM

BTW, I've found a very fast solid-state device.

They're planning on releasing an SCSI U160 and U320 device that can sustain 230MB/s. Right now the sales person that contacted me said that it should cost around $1K per Gig, which isn't too bad if you have a couple gigs on this thing to serve as a temporary capture device and then offload to another slower SATA drive. But again, load one of these puppys up (they're expandable to around 122GB I believe) and you're definitely not going to have to worry about lugging around a hard-drive array and any associated problems with RAID 0 or 1.

check it out at http://www.bitmicro.com/products_edisk_transit.php

Ben Syverson · August 3rd, 2004, 05:11 PM

If you only get 1 or 2 gigs, why not just get 2 gigs of RAM and record to that? Much less expensive...

Jason Rodriguez · August 3rd, 2004, 05:18 PM

For the Altasens you're going to need a lot more than 2Gigs, especially if you want to record 12-bit linear, which the chip is capable of.

Might be slightly pricey, but then again, this is for something that could sit nicely on your shoulder.

Ben Syverson · August 3rd, 2004, 05:44 PM

I'll be shooting with the Altasens at 720p and probably 10bit. 1080p at 12bit is a bit much for me right now. But I understand where you're coming from.

Do people out there really want an all-in-one shoulder-mountable ENG-style camera? I sure don't, especially if it will cost more. I don't do a lot of handheld shots -- so if the camera's going to be on a tripod or dolly anyway, I don't mind having a laptop sit next to it... The Kinetta is cool, but you pay a high price for an all-in-one solution. Not to mention the fact that it's not very easily upgradable. By using cheap and standard components, you can swap things out pretty easily...

I've done more research, and I think a good alternative to high-end solid state stuff is strapping together a few 7200rpm laptop drives in 2.5" FW800 cases. Stripe them into a RAID configuration, and hook them up to two or three FW800 buses (2 CardBus FW800 ports + built-in FW800 port). Check out this page at barefeats.com giving benchmarks for this type of configuration. They were getting 67 MB/sec over CardBus with a 2 drive RAID. I'm sure you could do much better with three or four drives.

How much is 67 MB/sec? Well, 1920x1080 @ 24fps in 10bit is around 60MB/sec. So you could handle that with just two pocket-sized external drives taped together. Or you could do 1280x720 @ 48fps in 12bit, which is around 63MB/sec.

I think cheap external RAID is the direction I'm headed.

August 3rd, 2004, 12:18 AM	#1291
Jason Keenan New Boot Join Date: Jul 2004 Posts: 19	The reality is that Its likely I won't get this camera. I'm just a geek so I like to learn geeky stuff. I'm looking at other cameras though so this stuff will probably apply. Re the hex stuff, I've done a little bit of assembly in my younger days. In reality it was mainly 'disassembly' so fairly basic, but I just wanted to know what I was dealing with if I decided to have a play at a basic assembly based bayer filter. It wouldn't be very good, but hey, it's just geek fun. As you say, I remember this discussion earlier in the thread but at the time I had no idea what it meant. Now i do, sort of. If I understand how the image is constructed, this will obviously be easier. Cheers Raavin ;)

August 3rd, 2004, 12:31 AM	#1292
Ben Syverson Major Player Join Date: Mar 2004 Location: chicago Posts: 434	Raavin: I totally understand. My own interest in this project is about 50% film geek, 50% computer geek. :) That's the ratio I like to maintain. I guess that adds up to 100% geek in any case. :)

August 3rd, 2004, 12:33 AM	#1293
Juan M. M. Fiebelkorn Major Player Join Date: Jun 2004 Location: Buenos Aires , Argentina Posts: 444	Ben, Do you have an aproximate ASA equivalent of the Sumix camera you got? Obin?

August 3rd, 2004, 12:38 AM	#1294
Ben Syverson Major Player Join Date: Mar 2004 Location: chicago Posts: 434	Juan, I'd put it at between 50 and 100 ASA. It depends on whether and how you're using the LUT -- which will also affect dynamic range. But at 8 bit, your choices as to how to use the range are more limited. There are definitely times when it seems equivilent to 100 ASA film (which I've shot a ton of), but with certain settings/light levels, it feels a full stop slower. Please note this is a totally emotional appraisal, because there's no good way to rate a CMOS/CCD sensor in terms of ASA. These sensors are linear, whereas film has a distinctive "S" curve response to light. So an ASA/ISO rating is only a small part of the picture.

August 3rd, 2004, 01:20 AM	#1295
Ben Syverson Major Player Join Date: Mar 2004 Location: chicago Posts: 434	I just got my 10mm Schneider Cinegon f1.8 lens in the mail today... This is a gorgeous lens. It's only single coated (multicoating is overrated), but it kicks the pants off of the multicoated Computar 8mm I've been using, and it's nearly as wide. It's sharp, high contrast, and has none of the barrel distortion I feared it might exhibit. I think this will become my main shooting lens, with the 8mm used for extra wide shots, the 25mm Angenieux for close ups, and the 75mm Angenieux for telephoto shots. God I love primes. The best thing about this whole HD camera setup is getting to work with primes again, and only using zooms when I want to. I'm anxious for Sumix to come out with their new software -- I'm ready to shoot!

August 3rd, 2004, 01:24 AM	#1296
Juan M. M. Fiebelkorn Major Player Join Date: Jun 2004 Location: Buenos Aires , Argentina Posts: 444	Ben, Do you agree with the 640 ASA rating given to the DVX100? (I ask this because I want to make a correlation between you camera and DVX to get myself a better idea about sensitivity)

August 3rd, 2004, 01:27 AM	#1297
Ben Syverson Major Player Join Date: Mar 2004 Location: chicago Posts: 434	I haven't used the DVX100 extensively, but 640ASA is downright laughable, unless you crank the grain. The DVX100 gives a much darker image than my GL1 at 0 gain, and I would put the GL1 at 0 gain at around 400 ASA. Shooting with the DVX100 is like shooting with about 200 ASA film in terms of the amount of light you need...

August 3rd, 2004, 01:31 AM	#1298
Juan M. M. Fiebelkorn Major Player Join Date: Jun 2004 Location: Buenos Aires , Argentina Posts: 444	I compared it with a photometer, and to me that scale of 640 was right.I used it everyday for 6 weeks, with and without Mini35 adapter and Zeiss Primes F1.2 . All the movie was shot at night with only the light coming from sodium street lights and in some ocassion the camera was more sensitive than my own eyes... I must accept that what you get is very dependant on Gamma adjustments , pedestal etc.... I didn't use more than 0 db gain setting. So you would say your camera is one stop less sensitive than a DVX100?

August 3rd, 2004, 01:42 AM	#1299
Ben Syverson Major Player Join Date: Mar 2004 Location: chicago Posts: 434	Juan, I haven't played with the DVX100 for months, so I can't give you a hard and fast comparison, but I would guess that SMX-150c is anywhere from a stop to 2.5 stops slower than the DVX100... Maybe more... But again, I'm not sure stop math is the way to think about the differences. For example, once the 10bit software is available, it may be possible to shoot 100% linear, which looks dark, and then apply a gamma curve in post to bring the image out and make it look "normal." If we can do that, it will effectively make the camera a stop to two stops faster, because we'll need less than half as much light to get a good image. But again, this is all non-linear for now, so it's rather nebulous. I'm witholding judgement until I see what an extra two bits (four times as many gray values) can get us...

August 3rd, 2004, 01:44 AM	#1300
Juan M. M. Fiebelkorn Major Player Join Date: Jun 2004 Location: Buenos Aires , Argentina Posts: 444	Thank you Ben. Very usefull info. It was just I'm too used to film terms and scales and it is the only way I can compare things :)

August 3rd, 2004, 04:59 AM	#1301
Wayne Morellini Inner Circle Join Date: May 2003 Location: Australia Posts: 2,762	<<<-- Originally posted by Jason Keenan : dealing with if I decided to have a play at a basic assembly based bayer filter. It wouldn't be very good, but hey, it's just geek fun. -->>> Yes, please do. Rob has had very good results (performance gains) going from straight C to include inline assembler. People are so used to C (and Windows) they don't realise how much of a ball and chain it is compared to assembler.

August 3rd, 2004, 04:45 PM	#1302
Jason Rodriguez Trustee Join Date: Mar 2003 Location: Virginia Beach, VA Posts: 1,095	BTW, I've found a very fast solid-state device. They're planning on releasing an SCSI U160 and U320 device that can sustain 230MB/s. Right now the sales person that contacted me said that it should cost around $1K per Gig, which isn't too bad if you have a couple gigs on this thing to serve as a temporary capture device and then offload to another slower SATA drive. But again, load one of these puppys up (they're expandable to around 122GB I believe) and you're definitely not going to have to worry about lugging around a hard-drive array and any associated problems with RAID 0 or 1. check it out at http://www.bitmicro.com/products_edisk_transit.php

August 3rd, 2004, 05:11 PM	#1303
Ben Syverson Major Player Join Date: Mar 2004 Location: chicago Posts: 434	If you only get 1 or 2 gigs, why not just get 2 gigs of RAM and record to that? Much less expensive...

August 3rd, 2004, 05:18 PM	#1304
Jason Rodriguez Trustee Join Date: Mar 2003 Location: Virginia Beach, VA Posts: 1,095	For the Altasens you're going to need a lot more than 2Gigs, especially if you want to record 12-bit linear, which the chip is capable of. Might be slightly pricey, but then again, this is for something that could sit nicely on your shoulder.

August 3rd, 2004, 05:44 PM	#1305
Ben Syverson Major Player Join Date: Mar 2004 Location: chicago Posts: 434	I'll be shooting with the Altasens at 720p and probably 10bit. 1080p at 12bit is a bit much for me right now. But I understand where you're coming from. Do people out there really want an all-in-one shoulder-mountable ENG-style camera? I sure don't, especially if it will cost more. I don't do a lot of handheld shots -- so if the camera's going to be on a tripod or dolly anyway, I don't mind having a laptop sit next to it... The Kinetta is cool, but you pay a high price for an all-in-one solution. Not to mention the fact that it's not very easily upgradable. By using cheap and standard components, you can swap things out pretty easily... I've done more research, and I think a good alternative to high-end solid state stuff is strapping together a few 7200rpm laptop drives in 2.5" FW800 cases. Stripe them into a RAID configuration, and hook them up to two or three FW800 buses (2 CardBus FW800 ports + built-in FW800 port). Check out this page at barefeats.com giving benchmarks for this type of configuration. They were getting 67 MB/sec over CardBus with a 2 drive RAID. I'm sure you could do much better with three or four drives. How much is 67 MB/sec? Well, 1920x1080 @ 24fps in 10bit is around 60MB/sec. So you could handle that with just two pocket-sized external drives taped together. Or you could do 1280x720 @ 48fps in 12bit, which is around 63MB/sec. I think cheap external RAID is the direction I'm headed.