Don Kotlos
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Posts posted by Don Kotlos
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It might help but it cannot be "the solution" unless Sony designed the back as a heatsink.
This heat problem is not making the camera useless for most non-professionals but at least for me there are two issues that will keep me from getting before extensive user reports:
1. How sensitive is actually the camera in warm weather. For example if I were to take a long hike under the sun, what the time limit would be then?
2. Sensor longevity. Heat can damage the sensor and hot pixels will start popping out. Cinema5D has already a hot pixel in their footage and even in long exposures of still pictures it is a problem as shown in several dpreview threads. Unless Sony provides a remapping feature I expect within a year to become a serious issue for video capture.
It might really not be a problem but I am not going to shell out $3200 before I know I can have a camera that will keep working as expected.
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Whats the 1080 verdict from the A7RII?
Yes that is something that I want to know as well. Both FF and S35 at 24p compared to the A7s, GH4...
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For those that own or have used the camera, does it feel like it could potentially cannibalize the sales of the A7s? Obviously, the A7s is better in terms of low light performance, but that's probably about it, right?
Well if you want to record long takes or for prolonged periods then A7s is your only choice.
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I agree. This camera deserves more attention.
It is a much better package than the DVX200 that was recently released from panasonic with a lousy image quality and a lousy non removable lens.
Here is a review from newsshooter: http://www.newsshooter.com/2015/02/24/testing-out-the-jvc-gy-ls300-a-4k-budget-super-35mm-camera-with-a-micro-43-mount/
@austinchimp That footage was terrible but from watching other footage online it has more to do with the person behind the camera/computer than the camera itself.
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No, that's another good one to test. I promise to do a full report, any other suggestions?
After the first overheating, see how much time it takes before you can start recording again and how much the second recording lasts before it overheats again. If within a minute you can record another 20min clip it might be alright but I doubt you can do that.
One problem with heat is that it is cumulative not a hard limit so you could even do a series of 5min clips close to each other and run into the same problem (but you don't have to test that).
Another problem with heat is that it will slowly damage the sensor. Pixel by pixel they will start going out. Now how easy is to map them out with Sony I don't know, but at least with the EM1 it is straight forward.
From what I see, Sony created a great camera but it is not targeted for any serious professional work. For that you will have to wait for the A7sII.
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picked up my a7r II today and the very first thing I did was see how it handles long takes.
20 minutes of record time in 4k 100 Mbit before the camera overheats and shuts off.
You get a warning message something along these lines before it goes blank though:
"Camera too hot. Let it cool down." How coy Sony.
This has to be addressed or I will have to return the camera. The s35 Jello is disappointing, but something I can deal with by sticking to FF mode for most of my shots. The camera overheating makes it a very bad choice for any kind of documentary or live recording. Its one of those things you can't explain your client. Imagine missing the moment because the camera overheated in room-temp.
I am sure it can handle longer takes in 1080p, but lets not try to find reasons to make something broken acceptable. I hope there is a way Sony can correct this, but it seems like more of a heat sink issue rather than something that can be fixed with a firmware update.
Yeah that doesn't sound good.
Did you try the FF 4k and see if it helps?
I wonder what is the max recording time is when I am shooting at even higher temperatures that are very common where I live.
I guess that is a very easy way of separating it from the future A7sII...
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Okay I'll do the 14bit to 10bit vs 8bit with both Log and normal gamma. Perhaps it's Log where 8bit will show its face.
The reason I believe testing from a single still image is the best way is because we remove all the variables, every single one. Just purely testing 8bit vs 10bit effect on an image. But if we record 10bit with one camera and 8bit with another, well massive variables enter here. Even if it's the same camera, the 10bit and 8bit in an FS700 have a ton of variables, and even GH4 10bit vs 8bit will have different codecs and different NR, bitrate, so skipping all that we begin with a single, simple rich source.
and supersampling is good to ensure we're testing perfectly full 10 and 8 bit, don't want claims that 10bit on a GH4 is really 9bit and so on (Which I have heard).
I am still searching for a codec that has the same characteristics in 8bit and 10bit versions. Any thoughts? (even a still photo compression format, or a codec). Windows Doesn't create ProRes sadly. And DNxHD has vastly different bitrates for 8bit and 10bit, 10bit being MUCH higher, so will not cut it for the test.
If anyone willing to do the test please share. Just any Raw image file you have on you drives and a way to compress it to 10 and 8 bit without variables.
You record 10 bit with one camera. Then can you convert that to an 8 bit video very easily.
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you're thinking of bits per pixel? which does not determine number of colors. https://en.wikipedia.org/wiki/8-bit_color color as defined by chromaticity, or chroma separate from luma. from above link on 8-bit color "The maximum number of colors that can be displayed at any one time is 256."
In the link you provided the difference in colors between 8bit and 10bit video is between "True color (24-bit)" and "Deep color (30-bit)".
8/10bit video means per channel per pixel per frame.
The two chromaticity channels (luminance independent) are useful when trying to describe displays since the luminance can be changed very easily and when compressing the video signal.
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to calculate number of possible colors per bit depth, the formula is 2^n where n=bit depth. 1bit would be 2 colors, 4bit would be 16 and so on. photoshop will call 8-bit "thousands of colors" but that's like marketing-speak, they're including all intensity levels, so 256*256, not only chromaticity values. 8-bit will always be 256 colors and 10-bit will be 1024.
?
8bits/channel --> 24bits/ image --> 16777216 colors.
10bits/channel --> 30bits/ image --> 1073741824 colors.
This is theoretically what can be recorded.
Practically,as I said in a previous thread, when recording skin with log 8bit image you will mostly get it within 1-2 stops of the dynamic range which reduces the color space dramatically.
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I disagree. I believe reworking a raw 14bit still to 10bit and 8bit and comparing is the most proper way to compare 8 vs 10bit scientifically.
Ebrahim, if you do that then the difference will be minimal indeed. The limitation of the 8bit/channel is when you are using a log curve as I tried to argue here. The reason is that you have to allocate a very small number of colors to each stop of the dynamic range. The reason that canon 8bit is great is because they are using a less aggressive log curve, that maps many more steps on the stops around mid-tones where the skin mostly lies. See here: http://www.xdcam-user.com/2011/12/canon-c-log-on-the-c300-compared-to-s-log/
The test is to have a camera with an aggressive log such as the s-log2 of the Sony and a 10 bit output. Record at 10bit and convert the ungraded version to an 8bit version too. Then try to grade both.
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Quite an interesting test that one.
Good to see the full frame mode is looking so good. The only time I will be using S35 mode is when I want to use ISO 6400+ and Speed Booster in very low light.
It was never going to be a minimal rolling shutter 4K camera from a 42MP sensor.
But even the fact it has less rolling shutter in 4K than the A7S does in 1080p shows an impressive step up in sensor readout speed. And that it is able to match the GH4 despite the enormous difference in sensor size and resolution is mind-blowing.
Yep I agree. S35 for these low light shots.
Here there is a quantification of the RS: https://***URL not allowed***/sony-a7rii-rolling-shutter/.
29ms. Same as NX1.
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Still too many words and not enough pictures on this thread!
Take some 10bit ProRes and convert to a high quality 8bit codec at the same bitrate (around 250Mbit/s would be good)
Then post screen shots of the image quality (hint - they will look identical) and also the grading issues you find (hint - you will never push it that far to breaking point in a real world grade)...
LOG is more important to image quality & dynamic range than 10bit vs 8bit.
The test should be grading a RAW still of a face and an 8 bit log frame. If someone has an A7s and willing to spend few minutes getting and posting the raw data here, it would be great so we can all try to match the two. Then after we all agree that is impossible to match the two
we can move on to the 10 bit. Sudopera's test is great (thanks!) but a V-log would make the differences even larger especially when shooting fine tonalities such as in skin. So I hope he repeats the test when the V-Log gets released...
I am attaching some crops from the video which I don't even have to identify. Differences are obvious.
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A7RII (S35) joined A7s and NX1 at the Jello party.
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8 bit is mostly a delivery bit depth. It is true that you can replicate most colors. Try to mess with the gamma and push the image around and you start seeing the limitations.
So one of the reasons that the C-log from Canon performs much better is because is not pushing the image as much as the S-log. It is using a normal gamma for most of the range and compresses the highlights more. That was a wise decision from Canon because they understand what an 8bit image can do and what it cannot.
Here there is more information:
http://www.xdcam-user.com/2011/12/canon-c-log-on-the-c300-compared-to-s-log/
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Was it all just a big prank and a joke?
Your words...
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Right, you said in 6 months the loss on the A7rII would be closer to $1000, I said no way anyone loses $1000 selling the A7rII in 6 months. Your link shows no change in the A7r's price until almost a year after it was released - which supports my point. The price isn't going anywhere in 6 months, it'll still be $3199 and mint used copies will be selling for a few hundred less regardless of whether or not there's a A7sII.
Did you actually select the "3rd party used" in the link provided? The selling price reduced by about 30%. 30% of $3200 is ~$1000.
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10 bit is a huge, huge leap... If the GH4 is still banding, then they must have screwed up their implementation or someone screwed up their tests.
10bit + a proper log is a very, very good balance of image quality and file size/workflow.
I agree. An 8bit/channel image has ~16M colors whereas an 10bit/channel ~ 1000M.
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They did a great job on the NX1 let's hope they can now do a great job on a raw shooting full frame camera
Don't tease us like that.
By the way if 10bit is the 'holy grail' even when compressed, why isn't everyone on this forum shooting 14bit?
I do enjoy our theoretical discussions...
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Doubt that, plenty of people are buying this for 42mp stills with no regard for video, its not dropping $1000 in 6 months unless Sony drops the price which won't happen for a year or so.
We were talking about how much you are going to loose if you buy now and sell in 6 months.
Look what happened with A7r:
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Magic Lantern already did... 14 bit raw. Medal goes to them.
I remember there were rumors of Samsung and ML collaboration. Any news on that?
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I always thought the chipset would have more work to do compressing to 8bit than 10bit? Any tech heads here?
No that is not correct. bit depth is not considered "compression". You just throw away the data. Similar to downsampling an image.
While is true that compressing more requires more work, compressing a 10bit footage for the same bit rate as an 8bit will require more work (more compression). You would need to increase the bit rate of the 10bit footage before your computational power equates that of the 8bit.
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You risk about $500 in resale, don't panic.
I bet within 6 months and after A7sII gets announced it will be closer to $1000.
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Making their models obsolete might seem like a bad strategy, but what they achieve in the meantime is market domination.
This an interview of a Sony manager that I found on SAR today...
"Sony will concentrate on full-frame cameras in the future. In the short run, we will target existing full-frame camera users and then attract those who use entry and mid-class models to upgrade their cameras in the long run, raising the popularity of full-frame cameras. To do so, we plan to boost our presence in the professional market such as photo studios and wedding photography. Besides the stagnant growth of the camera market, the entry-class segment of the lens-interchangeable camera market is slowing down drastically.
We held a 59 percent share in the mirror-less camera market last year and have been the top seller of mirror-less cameras for the last five years, but we have never topped the gross lens-interchangeable camera market on a yearly basis. Our goal this year is to become the leader in this market for the first time." -
Hi,
Was the ungraded version shot in FF or Super 35mm?
This is from their main article: "In this video I used both shooting modes and I dare you to spot the different between them….(1:45 to 1:51 is a good example)."
we can move on to the 10 bit. 
A7Rii Overheating Problem Solved
In: Cameras
Posted
That is very interesting. Still not perfect but at least it seams to be oNE solution (not for me though cause I hate external recorders). I wonder what processing is being done and if it affects the output quality.
Another interesting thing that I found out is that Sony does have an automatic remapping method that runs every month or so. So you can set the date few months ahead to have the remapping and then back. I don't know how it helps in video but in stillsas shown in dpreview it does the job.