after reading some post NOW I'm a bit confuse what would be the different between a 4K raw file coming from the Odyssey 7Q versus the one coming from the HXR-IFR5? I'm familiar with RED footage where I can Change ISO, WB, Color space, Etc. What level of control we have with the FS700 and the external recorders?
RAW vs raw? Odyssey 7Q vs HXR-IFR5?
- Thread starter KV Films
- Start date
RAW, should be RAW, period. What it actually means is that you are recording the data unprocessed from the photosites of the chip, a straight value for each one, corresponding to how much light has fallen on it.
By "unprocessed" that means before the data has been adjusted for ISO, WB, Color space, Etc - also gain, gamma, you name it. It will also be a single value for each photosite, so in a sense monochrome. The colour comes from the fact that each photosite has an R,G,B filter over it and the software knows which filter went with which. Hence, RAW data needs deBayering as part of the processing as well, to make a proper colour image at all.
Now for processed video, 8 bits is completely sufficient bitdepth for display and viewing - the human eye is not capable of distinguishing more. If it's processed, but likely to be further graded, 10 bit is considered desirable (if the camera is good enough) together with a flat image to preserve detail. But for RAW, it needs to be much more, typically 12 bit or more because of the large amount of manipulation to be done on the data. The sensor may be capable of 12 stops of dynamic range - the human eye isn't, hence why 8 bits is good enough for final display. But the system that captures the RAW data needs to be able to handle that, such that it's all available for the processing into an image that looks pleasing to the human eye.
By "unprocessed" that means before the data has been adjusted for ISO, WB, Color space, Etc - also gain, gamma, you name it. It will also be a single value for each photosite, so in a sense monochrome. The colour comes from the fact that each photosite has an R,G,B filter over it and the software knows which filter went with which. Hence, RAW data needs deBayering as part of the processing as well, to make a proper colour image at all.
Now for processed video, 8 bits is completely sufficient bitdepth for display and viewing - the human eye is not capable of distinguishing more. If it's processed, but likely to be further graded, 10 bit is considered desirable (if the camera is good enough) together with a flat image to preserve detail. But for RAW, it needs to be much more, typically 12 bit or more because of the large amount of manipulation to be done on the data. The sensor may be capable of 12 stops of dynamic range - the human eye isn't, hence why 8 bits is good enough for final display. But the system that captures the RAW data needs to be able to handle that, such that it's all available for the processing into an image that looks pleasing to the human eye.
ISO can't really be changed within RAW because ISO is set before the raw image is even recorded. Setting ISO is akin to setting aperture and shutter.
Even with red code, you can't change ISO. ISO is the amount of gain the amplifiers have whilst reading from the image sensor, prior to converting the signal from analog to digital.
Anything you can do with a raw photo from a still camera, you can do with raw video footage. But, with all forms of raw, even red code, you can't change shutter, aperture, or ISO.
Redcode is simply a proprietary lossy compressed raw.
brazzam
Well-known member
Also it's important to note that the 7Q cannot, as of now, record 4K RAW, only 4K compressed. The 7Q can do 2K RAW, though. This is not due to limitation of the 7Q hardware, but due to the licensing agreement between Sony and Convergent Design. Unless Sony changes their mind, this limitation will most likely remain in place.
The only way currently to get 4K RAW from the FS700 is the Sony HXR-IFR5 solution.
Last edited:
True North
Well-known member
Good points
The other limitation is that the Sony Solution can record 4K @ 60p, the 7Q cannot. I seem to remember that this was a 7Q limitation (which may change down the road) and not a Sony imposed limitation.
Michael Erlewine
Well-known member
Not entirely off the topic. I have a Sound Devices PIX 220i video recorder. If I am not that concerned about 4K, how does the PIX 220i compare to the Odessey7Q in terms of what it does?
Nowhere near as close for 2 reasons. The PIX220i isn't as powerful and maxes out at 1080p30 or i60. Also, above 1080, at 2k/4k, the FS700 outputs an encoded stream, which is why CD had to license tech from Sony in order to be able to decode, before debayering/re-encoding.
brazzam
Well-known member
The biggest for me is the embedded OLED monitor that comes with the 7Q. This monitor/recorder combo is just too enticing for me. Any chance I get to consolidate the amount of gear I have to take on a shoot is a big draw for myself.
Also, the FS700's Super Slow-mo modes are only supported with the 7Q or with another third-party recorder that can handle 1080 60p. Last time I checked the third party recorders that can handle 1080 60p are more expensive than (or at least comparable to) the 7Q, but those third-party recorders do not also serve as monitors nor can they do continuous recordings of the high frame rates. (1080 60p recorders are limited to only recording what comes off the internal buffer of the FS700.) So the 7Q still comes out on top as the better bang for the buck, in my opinion.
Granted, until we see the shipped version of the product, we don't know for sure the quality of the product... but so far, on paper and with the confidence added by Dan Keaton's attentive posts on these forums, the 7Q seems like my definite next purchase.
Not as simple as that. There is a "shooting ISO" and a "processing ISO", for want of anything better to call them. Shoot a JPEG and they are one and the same thing - the processing to form the JPEG "burns in" the ISO setting, which is one reason why the ability for post correction is so much less.
With RAW it's different. You set the "shooting ISO" to control the shutter/aperture (as you say). Ideally, that will make most use of the dynamic range of the sensor - which is why it is usual to think of a "native" ISO for any given sensor.
But set the "shooting ISO" higher and it will ask you to reduce aperture or shutter speed. Result will therefore be less light on the sensor and the digital value output will be less. No problem, if the camera or software uses the same value for processing, it will compensate, effectively adding digital gain. Go too high and expect noise as the least significant bits of the digital value get used more significantly - as we observe.
Now imagine you set the ISO to it's "native" value, go to take a photo, and the flash doesn't fire. If set to output JPEG, the same ISO will be used to process the data and result will be an underexposed image, with little that can be done to correct. If set to RAW, and you use a higher ISO as the processing value, you may be able to compensate - the result will be the same as for a JPEG with the same aperture/shutter speed, but that higher ISO value set on camera.
You don't set ISO to control aperture/shutter. Aperture, shutter, and ISO are all functions, 3 separate functions, of the camera that cannot be changed after recording, is what I said. Aperture is the size of the hole in the lens, shutter is the refresh rate of the sensor, and ISO is the gain on the amplifiers prior to analog-to-digital conversion, which is why if you turn up the ISO, you are also amplifying noise from the image sensor, thus the high ISO = lots of noise issue.
Once they are set and recording has started, that is it, you can't change them like you can change other things in a RAW image.
Looking up some other references, techniques seem to vary between cameras - some (as you say) make more use of analog gain before the A-D convertor, others don't. (Such as Red.) Worth looking at what they say - http://www.red.com/learn/red-101/iso-speed-revisited
I also checked RAW files in Photoshop and whilst in that case they don't specifically say you can alter ISO, the RAW viewer gives an "exposure" adjustment function, which gives far more control than tweaking a JPEG file. Since aperture/shutter speed were fixed at time of shooting, isn't that effectively the same thing as varying ISO in post? ( I suspect it is - but the amount you can do it is probably less with this type of camera than at time of shooting - unlike Red.)
Probably depends a lot on RAW bitdepth - the higher that is, the less point in varying analog gain whilst shooting.