horshack

Quick Description:
Precut is an open-source app I wrote that renders video files from an Adobe Premiere Project without transcoding/recompression. Its purpose is to reduce the storage requirements of your source media by letting you prune your source files to just the portions you need. Precut uses ffmpeg to perform its work, so it should be compatible with nearly every codec and video wrapper available.

Here is the homepage for the app:

http://testcams.com/precut/

And here is a YouTube demonstration:

BM had free hands-on training for Resolve at NAB this week. Three-hour course. They had 50 Macbooks set up in a large meeting room. The trainer was excellent. I left very impressed with the product (I use Premiere). Earlier in the day I was in BM's booth and grabbed one of the employees to ask a question about the interface - he knew the program inside-out. I asked him what he did at the company and turns out he's one of the software engineers for Resolve. Software engineers on the trade show floor interacting with prospects and customers? Now that is impressive!

This is surprising. By quite bad did you mean detail or noise? Did you see the poor results in both FF and Super 35mm modes for 1080?

Unless you like to use full-time AF for video. I doubt the A7rII will match the NX1 in this regard:

https://www.youtube.com/watch?v=0DigAgYD-QY

https://www.youtube.com/watch?v=znoDaqWLt9E

FYI, the NX1's H.265 may be DOA due to licensing royalties:

http://blog.streamingmedia.com/2015/07/new-patent-pool-wants-share-of-revenue-from-content-owners.html

http://yro.slashdot.org/story/15/07/26/0149234/hevc-advance-announces-h265-royalty-rates-raises-some-hackles

​There are other inconsistent fields as well. For example, the ACR-generated focal plane resolution fields are for a 36MP A7r:

From linked image:

Focal Plane X Resolution        : 2049.067291
Focal Plane Y Resolution        : 2049.067291

From an A7r image processed in ACR:

Focal Plane X Resolution        : 2049.067291
Focal Plane Y Resolution        : 2049.067291

From an A7II image processed in ACR:

Focal Plane X Resolution        : 1675.257385
Focal Plane Y Resolution        : 1675.257385

"The 15 stops is done by taking the raw sensor data and running it through dual image processors at two different ISOs (high and low) before making a composite image from the dual raw stream."

This sounds like the "Dual ISO" feature of previous Canon sensors that Magic Lantern unleashed for stills. Andrew, what is your source that the C300II is using this technique?

Has every serial killer spent a decade planning and exhibiting bad behavior and every common assault perpetrator only a few seconds exhibiting his? It could be argued that Clarkson's years of progressively worsening behavior toward others that ultimately escalated to violence is an imputed form of planning. Certainly Clarkson was aware that his behavior toward others was unacceptable yet he failed to stop its progression. That means he's either guilty of consciously planning his bad behavior or guilty of consciously not planning to correct it.

As for my intelligence, I would kindly ask we limit the debate to the topic at hand and not try to color the discussion with personal insults.

​How could we know that if we don't know interact with them on a regular basis? The same as how we can't know how normal Clarkson is for the 99.999% of the time he's not pummeling his producer.

​Serial Killers spend 99.999% of their time living normal lives. But the .001% of the time they spend murdering people is rather significant.

Nobody should be allowed to keep their job after physically assaulting a coworker. The rest of the discussion is just moral relativism gobbledygook. Clarkson  isn't a scientist inventing a cure for cancer - the world will go on without him, including the careers of the victimized parties.

Jeremy Clarkson 'to be sacked TODAY' after BBC probe finds he launched '30-second attack' on Top Gear producer during steak dinner 'fracas'

http://www.dailymail.co.uk/news/article-3010167/Top-Gear-presenter-Jeremy-Clarkson-sacked-BBC-internal-investigation-concludes-did-attack-producer-steak-dinner-fracas.html

Making cameras as seamless for online operation as Smartphones will make existing camera enthusiasts happy but it wont do anything to bring the P&S and DSLR market back. That ship has sailed. Most have no reason to buy a separate camera.

WIth LA-EA4 you'll get much better AF vs Metabones but you'll pay a 1/3 to 1/2 EV noise penalty due to the SLT.

The 1DC grabs look decidedly soft vs the A7s, as does nearly every other DSLR compared to the A7s. Any color issues can be corrected in post - acuity not so much. For IQ alone I would take the A7s over the 1DC.

​I'm going to redo this with a resolution chart. I made a poor choice of subject for evaluating resolution

Here's a base ISO comparison with the same cameras, including a comparison with the D800/D810 moved back to match the D750's wider crop. Not sure I picked the best subject for the comparison. All using Zeiss 35mm f/1.4 @ f/8, Cloudy WB, Standard Picture profile, 1/50 ISO 100.

https://www.transferbigfiles.com/2c0a7a0c-d7c5-4298-b728-ad49bab8bd1c/J1jQVSQY-eNa1eX5r5IWag2

Thanks I downloaded it. I don't know if it is the lighting, but they seem to be better than I thought they would. At first I thought that it was the crushed black, but using Gom player and lifting the lows the noise is still very nice. The D750 is cleaner and in this lighting even the 12800 looks very nice and 25600 usable. The D810 6400 iso still looks good with lots of resolution and very nice filmic noise and 12800 would be usable. The D800 is clearly a step below those two in terms of noise and resolution.

 

From what I have seen before they all look better by 1 stop from what I thought. In other footage the D750 seemed to have a sharp degradation of the quality between Iso 10 000 and 12 800, did you see the same.

 

I can also understand why the D810 was chosen for that big studio Australian Movie. It has a lot of resolution and it retains a lot of detail even at high ISO. You can easily shoot at 3200 ISO with a ton of detail. This is enough for any movie.

The D800's video IQ drops off a cliff between ISO 6400 -> 12800, whereas on the D810 and more so the D750 the decrease is more linear. Btw I'll try to get a base ISO video comparison done tomorrow.

Here is the original video file for download - the following link is good for 5 days or until the download quota has been exceeded:

https://www.transferbigfiles.com/e9270268-c766-48f3-b271-05c18076a3f9/WRxTxw2Cd9aocePN4nIvvg2

Thanks for the review Andrew. Regarding your High ISO comments about the A7s's ISO 12,800 being equivalent to the A7 at ISO 3,200, my tests indicate the A7s doesn't start pulling ahead until ISO 12,800, at least for stills (which is the context you made your comments in). Video of course a different matter. Here's a carefully-controlled High ISO stills comparison I did between the A7r/A7/A7s, all normalized to the same resolution (stills): http://***URL removed***/forums/post/54031579

This 5DM3 vs D750 comparison (

What I am not understanding from the article is it implies that at large apertures, the camera is automatically compensating by increasing the ISO, but the user is unaware of the ISO increase? 

 

 

So the camera says, for instance, ISO 1600, and the camera is really at ISO 3200?

 

Michael

Yes, on a noise basis that is effectively what happens. On an exposure basis it matches the user-indicated ISO.

I would think another significant problem would be the decreased efficiency of the micro-lenses in front of each pixel.  The larger the micro-lens the more efficient?  Or, the smaller the micro-lens, the less efficiency, especially in low light.  

One issue with the microlenses is that they have an associated max aperture, like normal lenses. Producing very large aperture microlenses is difficult and expensive apparently, so commercial sensors have to compromise a bit. The downside of this compromise is loss of light when using large aperture lenses, mostly at f/1.4 and larger. You can read it about it here: http://www.dxomark.com/Reviews/F-stop-blues

A lower resolution sensor holds a massive advantage for video. You can downscale a 36MP still to 2MP and say "look how clean" but pixel quality is pixel quality, signal to noise is signal to noise, there's far fewer ways to fudge the facts when it comes to video.

That's only because sensors and sensor procesisng ASICs aren't yet fast enough to process higher MP streams for video. It's not a pixel quality issue since those same high MP sensor produce equal or better IQ than their lower MP bretheren for stills, for everything except the very extreme High ISOs (+12,800 for FF).

HI horshack, I did read that thread but had difficulty understanding.  It seems misleading when you say, "cumulative read noise".  PLEASE correct me.  I would think that on a set of 4 pixels (pre de-bayering), you would get more sensitivity at high ISO, and less noise, then a similar block of 16 pixels fit into the same space.  I can see how you could say the cumulative noise is less on the 4 pixels, then 16 pixels, but isn't that obscured the prime difference between different size pixels?  I can understand that experimentally, it makes sense to look at cumulative read noise, but in explaining the difference to filmmakers, isn't it better that they think in pixels?

 

On the base ISO issue, it seems that comparing 4 pixels against 16, or 1 against 4, allows one to visualize the difference between say having a dish microphones vs an omnidirectional.   

The typical analogy used is buckets of water. Four small 8oz buckets placed side-by-side hold the same amount of water as a single 32oz bucket. Since the smaller buckets are side-by-side you would expect some loss of water when pouring into them for the gaps in between the buckets; this is where sensor microlenses come in. They act as a funnel to keep water from spilling around the sides of the extra boundaries/edges of the smaller buckets (ie, the funnel light into the photosensitive portion of each pixel, preventing the light from reflecting off the additional edges of smaller pixels). You'd be surprised to learn that the highest-efficiency sensors available right now for any commercial camera are tiny P&S cameras, where they convert 75% of the light they receive, vs 56% for the best full-frame sensors.