Jump to content

dahlfors

Members
  • Posts

    683
  • Joined

  • Last visited

Posts posted by dahlfors

  1. I managed to load the updated product page http://www.blackmagicdesign.com/products/blackmagicpocketcinemacamera (without images though):

     

     

     

    Record to SD Cards
     
    Blackmagic Pocket Cinema Camera features a built in SD card recorder that captures stunning ProRes 422 (HQ) and lossless compressed CinemaDNG files to fast SDXC cards. As an open format, it's compatible with most popular NLE software so you get a digital camera that's perfectly designed for post production workflows. When you’ve finished recording you can easily mount the card straight into a laptop, ready for editing. You can even color grade direct from the card with the included DaVinci Resolve Lite! SD cards are commonly available and can be formatted for either HFS+ or exFAT, making them compatible with either Mac OS X or Windows.
     
    - so internal raw recording to SD!
  2. Interesting info on the compressed Cinema DNG being 8-bit. You made me look it up in the specs:

     

    DNG Version 1.4.0.0 adds support for the following compression codes:
     
    • Value = 8: Deflate (ZIP)
    • Value = 34892: Lossy JPEG
     
    Deflate (8) compression is allowed for floating point image data, 32-bit integer image data and 
    transparency mask data.
     
    Lossy JPEG (34892) is allowed for IFDs that use PhotometricInterpretation = 34892 
    (LinearRaw) and 8-bit integer data. This new compression code is required to let the DNG 
    reader know to use a lossy JPEG decoder rather than a lossless JPEG decoder for this 
    combination of PhotometricInterpretation and BitsPerSample.
     
    So in Cinema DNG 1.4+ there is lossless compression with zip compression as well as lossy compression with JPEG, which is 8-bit.
     
    Some kind of comparison of standard DNG to Lossy DNG to JPEG: http://blogs.adobe.com/lightroomjournal/2012/10/dng-1-4-specification-notes.html
     
    It looks like the lossy DNG is supposed to have more data than a JPEG file at least, both sizewise and in the preview image. I don't get it from the spec how it is supposed to work though. Maybe someone else knows more about these formats?
  3. One problem with the BMCC mini: how the hell do you record uncompressed RAW to SD cards?

     

    EDIT: Looking around, seems you'd want a bunch of these:

    http://www.bhphotovi...emory_Card.html

    You'd need at least a 125 MB/s write speed. 128GB gets you 15 minutes of footage, so still better than the film days. And of course, you can reuse the cards.

    Pro-Res is of course the saner option.

     

     

    The BMC Pocket Camera does compressed raw too, which is about 3:1 compression ratio. So, for 1080p 24 fps you should see data rates at around 27-30 MB/s. Would be great if it can do 1080p50/1080p60 as well, which would roughly be the double bitrate - but I don't have my hopes set too high on that.

     

    EDIT: This was an estimate according to the CinemaDNG specs for lossy compression. Seems like the cameras are using lossless compression (zip), which means that the data rates are totally different.

  4. one more thing that was mentioned elsewhere about the pocket camera: with the cropfactor of the sensor a 7mm full frame equals roughly 21mm on this baby. so it wont be easy to get really wide on that camera. still for that price and package i am all sold!

     

    With the m4/3 lenses you will get quite wide. Also keep in mind the Metabones Speedboster. I bet that will be a perfect fit for this camera :)

  5. Mongolia & Himalaya - then you will have another issue: altitude.

     

    Traditional hard disks rely on air pressure inside, and they are limited to around 3000 meters maximum operating altitude.

     

    I think your only choice here is to get one or several SSD:s.

     

    Could perhaps also work if you use a bunch of flash memory cards at the higher altitudes. Keeping a hard disk powered off is alright at higher altitudes, but don't power it on much higher than 3000 meters, or your disk is likely to break.

  6. SSD's cost around 150 euros and upwards for 250 GB, over 300 euros for 500 GB sizes.

     

    SSD's are the most rugged ones for sure. Hard disks are far more sensitive to rough handling and shocks than SSD's. However, they are the most sensitive when they are powered on. If you eject hard disks safely before powering off - hard disks park their mechanical parts (arms with read/write heads). When in parked state, hard disks can withstand quite a lot of shocks and rough handling.

     

    So, if you want lots of storage for a cheap price, hard disks are the way to go. If you want the absolutely best ruggedness but can survive on a bit smaller storage, SSD's will be the best choice.

     

    Depending on where you travel, you want to keep both SSD's and HDD's dry. In jungle-like humidity you really would want to have some kind of sealed box/bag with something that absorbs humidity, like silica gel.

     

    I've seen how bags get treated at airports, and would it be me, I'd be sure to keep the portable disk as hand luggage, wrapped in a sweater or so. Normal carrying like that in a backpack or so shouldn't be a problem if you aren't unusually careless about the bag.

     

    When it comes to the casings of the hard disks, I wouldn't care too much about if it is padded or not, that's mainly cosmetic. What I'd care more about would be the cooling properties of the hard disk case. According to largescale tests done by larger data centers, hard disks have the least amount of failure if they run at around 30-40 degrees celcius. Cooler or warmer running increases risks for failure.

     

    My personal recommendation for traveling storage on the cheap would be to get two portable hard disks, one for backup, then using same transporting & dry keeping for both of the disks. If they'd get banged around enough to break - you got a good chance that one of the disks survive at least. Hard disks are the same all around the world as well, so you'd easily be able to get a replacement for backup if one would break down.

     

    Also, any portable hard disk that has the right interface for your mac (USB/Firewire) will work, no real difference.

     

    My own solution is to get any cheap metal (better for keeping drives running cool) casing I can find for the interface I need (usb/firewire/esata), and then I drop in just a normal 3.5" hard disk. No reason for you to do it if you need a new case, I just do so because I usually have a lot of extra hard disks lying around.

  7. So far the Nikon 16-35 f/4 VR for me seems the best option - only the focus ring on the lens does not move very fluid. It has this strange friction to it, that some of the modern nikon zooms have. So once you start focussing manually, you will somehow move the camera. That was the good thing about the Sigma lens - the focus ring runs very easy and fluid in manual mode.

     

    I'm with you on this one. I can never really like the new plastic feeling in the modern lenses. I'm all for the old classic metal constructions with solid feel for aperture & zoom. 

  8. Unbelievable that the aperture issue on the D5200 is that much crippled!

     

    The AI / AI-S lenses are all without chips. A few of them are still manufactured and sold by Nikon, others you can find for nice prices used.

     

    As a normal lens for APS-C crop as on D5200, I'd recommend these all manual lenses:

     

    1) AI-S 28/f2.8 http://www.kenrockwell.com/nikon/28f28ais.htm

    2) Voigtlander 40mm f/2 SL-II http://www.kenrockwell.com/voigtlander/40mm-f2.htm

     

    The older 35mm lenses might be alright for HD video resolution, but they are nowhere near these two lenses in optical performance. They tend to have a bit of barrel distortion though, which might/might not impact the APS-C crop.

  9. These are pretty advanced topics, since we are now dealing with "tricking the visual perception". Does anyone know of some place I can find detailed info on this?

     

    Tricking visual perception has been done a long time in art, and yes, how the human brain interprets visual information is a big subject.

     

    I'd recommend that you experiment in Photoshop with upscaling on some stills (a lot faster and easier to work on a still). Pick some sample stills that you can find, one squeezed anamorphic still and one normal still with no squeeze.

     

    Then use these techniques - I often use them myself in my design work if I for some reason have photos that aren't detailed enough:

     

    1) Depending on the image, add one round of sharpening with smart sharpen at around 1.5-3.0 pixel radius, with amount around 5-15%,

     

    2) Then add a second sharpening with 0.2-0.5 pixel radius at a bit higher amount, 15-45%. The values depends a lot on how it's going to be used, and the original resolution of the image.

     

    3) If I want yet more perceived resolution I add one noise layer in overlay mode and tweak that to what I like. Since you do it for screen use, you use quite little opacity on the noise layer (how large of an opacity value you will use also depends on how much contrast your noise layer has). When working with print as output medium - you use far more noise (the print process hides most of the noise you add in fact).

     

     

    Experiment with different settings and put the images side by side to compare. You will notice that you can get a lot more perceived resolution when you sharpen the right way, add grain - and do only horisontal scaling as in the case of anamorphic...

     

    - Same methods can be applied for video as with the stills - the difference will be that your noise is animated and that you don't necessarily run two rounds of sharpening. These methods (except horisontal-only scaling as with anamorphic) have been used for print medium a long time. For print you can successfully scale upwards to 150-200% without much perceived loss of resolution, even more when it goes for billboards or something that will be viewed at a further distance.

     

    - Basically, most kind of grit / noise / dirt / distortion layers layered on top with a bit of opacity will increase the perceived resolution. In the early days of web design when high res digital photos were harder to acquire, people used scanlines so much for this reason - that it became a popular design style (similarily to this image: http://fc06.deviantart.net/fs70/f/2010/081/9/f/Labrador_Wallpaper_Scanlines_by_Red_Se7en.jpg). Scanned filmgrain or noise will be what you want for video.

     

    Similar methods for upscaling were previously commonly used for 3D animations to save on render time previously when hardware was a lot slower. Genuine Fractals was the name of a tool specifically made for upsizing, yielding even better results than traditional upsampling algorithms. These days it has been renamed "perfect resize": http://www.ononesoftware.com/products/perfect-resize/, but it's unfortunately not a plugin for video softwares and if it is used on video, it needs to be run frame by frame.

     

    With these upscaling methods you'll notice that upscaling can produce very good results. Thanks to anamorphic needing only horisontal scaling, end result is even better.

  10. About the Tamron 17-50, check out this video review that compares Nikon, Canon, Sigma and Tamron 24-70 lenses: http://youtu.be/xat-cF1Aess?t=3m59s

     

    The Tamron 24-70 seem to work quite alright with video stabilisation, and I assume the Tamron 17-50 should be around the same performance. 

     

    Don't expect magic wonders from image stabilisation, though. It surely helps with image stabilisation and with some additional tricks you can probably get it quite stable while still being quite invisible. If you can get one point of contact with your body - it will help. Perhaps even with camera strap somehow.

     

    Practice also helps. My video here is shot with D800 + 50mm f/1.8 lens with no VR:

    https://vimeo.com/44419968

    In the video I'm holding the camera with my right hand, left hand constantly on the focus ring of the lens - so this is quite close to your invisible shooting. Using the camera like this makes your focusing hand VERY tired, so for longer shoots it won't be an option.

     

    I have the Nikon 16-35 f/4 VR. On fullframe at 16mm it has a bit of distortion, which will be a lot less on an APS-C camera like D5200. From 20mm and upwards, there won't be any distortion on the D5200 since it's just using the center crop (very minimal amount of distortion from 20mm and upwards on a fullframe D800 too).

     

    Unfortunately I haven't used the 16-35 for filming anything, just for stills, so I have no comments about VR & filming on that one, yet.

  11. EDIT
    About the sensor size, the RED One has a 35mm sensor, while the 5d3 has a full frame sensor, so, that's almost 40% wider field of view on the 5D, which is what we see in the video!

     

    You mean: RED One has a S35 sensor, while the 5d3 has a full frame 35mm sensor :)

    Comparison image here: http://www.eoshd.com/wp-content/uploads/2011/08/sensor-comparison3.jpg

     

    And regarding original poster:

     

    Yes, anamorphic lenses are made to squeeze the image as much over the whole lens. This means - even if you just use the center area of the anamorphic, it will squeeze in the image there as well - which you confirmed with your test.

     

    That the RED One S35mm sensor is smaller than a full frame sensor results in, means that you can use a wider taking lens than on the full frame 5Dmk3 without getting vignetting. 

  12. Many cameras do vertical line skipping on the sensor to achieve 1920x1080 resolution, due to limited in-camera processing capabilities and how the sensor reading works - from top to bottom, line by line.

     

    This means that each horisontal line has the full line readout to use for downsampling, which if the in-camera processing is maintaining quality good enough should result in cameras having better quality/resolution on the image horisontally than vertically (where resolution & data gets lost due to lines being skipped).

     

    This is good for anamorphic use, since we stretch out the footage where there is most of the resolution & detail. If the upscaling interpolation is done right and with a bit of grain as Caleb mentioned - you will perceive the resolution as being better.

     

    If you compare an upscale from 2x anamorphic, 1920x1080 -> 3840x1080, the result of that will be perceived as having much more resolution than an upscale from 1920x1080 -> 3840x2160 - since then your footage has been scaled in two dimensions, which makes it much more noticeable.

     

    "Gain resolution" is not the best term in my opinion. Closer to the truth is: "you perceive it as much more detailed even when upscaling it horisontally, since the vertical resolution is still full res".

     

    For Blu-ray output, you'll have to squeeze your footage vertically instead.

     

    If you want higher output for theathers, your best option would be to deliver as a digital cinema package. Some more info about that available here: http://nofilmschool.com/2012/07/project-in-digital-theater-make-digital-cinema-package-for-cheap-with-opendcp/

  13. And not just manual lenses. Any Nikon lens with an aperture ring will give you the ability to change aperture while shooting: AI, AI-S, AF and AF-D lenses. The ones to avoid are the modern lenses, marked with 'G'. You can read a bit more about the differences of Nikon lenses here: http://www.kenrockwell.com/nikon/nikortek.htm

     

    Same thing applies to any third party-lenses from Sigma, Tokina, Voigtländer etc - as long as there is an aperture ring, you can change it while shooting.

     

    EDIT: Apparently D5200 is crippled with any lens with a chip. Is there anyone that can confirm that this is the case with D600 & D7100 as well? These cameras might differ since they are built to be used with older AF lenses that need AF motor builtin to the camera body.

  14. Hah, just a link - not an embedded video/still or anything to advertise this great piece!

     

    Congratulations man, that's some awesome footage. Think you'll sell a few cameras for Panasonic when showing off that kind of footage :)

  15. To me, the result in the video seems like it could be corrupt/missing info from color channels. If it is, that could be 1) corruption while writing video to memory card, 2) corruption while processing the video in-camera. 

     

    So, my first step would be to find out if this can be reproduced with another brand of memory cards, or if it is just that one card.

     

    Otherwise, it might be some hardware issue or firmware issue.

  16. The sensor outputs 4K raw at 30fps or 60ps, and the limited consumer Nikon image processor can do as follows:

     

    Actually it is not that limited for an image processor in a consumer camera: http://en.wikipedia.org/wiki/Expeed#Expeed_3

     

    Would be interesting to see a new processor of this kind with SATA controller built-in (Since SSD's are large in size, maybe they could have eSATA port on camera - just like the current gen has HDMI). Would probably be quite doable, and fast enough for pushing RAW or some 10-bit format :)

  17. The topic of this thread is "best and most reliable external hard drives". Let me tell you - there is no such as a reliable hard drive. Whatever brand (there's only Western Digital and Seagate left in the 3.5" rotating platters business) you pick, you might get a bad drive that will die immediately, after a few weeks/months or so...

     

    Best solution for reliability is like soupkitchen said to run disks in RAID. RAID-5 is alright, but personally I'd go for RAID-1 in your case - this means you can run the RAID with 2 hard disks - and everything that is written to the RAID volume gets written to both hard drives. It is less likely that both of the hard disks die at the same time, so you gain a bit of reliability this way. 

     

    Cheapest solution for this is to use a USB 2 or Firewire enclosure. You could also go for a small 2-bay NAS.

    Make sure to stay away from any enclosure that only does RAID-0 - this will only increase the risk for failure.

     

    Another cheap solution, is that OS X actually has software raid built-in, so you could actually hook up two external hard disks to your Mac and setup software RAID in OS X.

     

    Since you are asking this question, I guess that you aren't too experienced when it comes to managing disks / raids etc. In those cases, a NAS would most likely be the easiest hardware to setup for you. Two good brands to have a look at are Qnap and Synology.

     

    These are generic advice for keeping data alive on disks. I see Axel suggests a workflow that will keep redundancy in files as well through work disk + project disk. Probably OK as well. Had it been my own very important data that I didn't want to disappear, I had used work disk + backup on RAID though.. The question about hard disks is not IF they break, but about WHEN.

  18. Any idea on what resolution the live view output is over USB? For the Nikons, I think it will be far below the quality of the HDMI output, and probably not even better than monitoring on the rear LCD.

     

    Too bad the only solution with tablets is to use USB since no tablets have HDMI-in. I'm still hoping that some tablet manufacturer will find it reasonable to include HDMI-in sooner or later...

×
×
  • Create New...