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Don Kotlos

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Posts posted by Don Kotlos

  1. Just received the A7rII. 

    Late in the night, I just mounted both cameras on the same plate with a heavy handle and did a quick & dirty IBIS test. I just moved around without trying to shake the cameras like crazy (ok maybe just a bit at some point :) ) . There might be some extra movement because of the stability of the rig with the cameras (but both cameras do physically move the same way). 

    Settings are as close as possible. 1/60 f/1.4 ISO 800 WB3100. 

    25mm T0.95 SLRMagic + Tiffen UC3 on E-M1, 50mm f/1.4 AIS Nikon on A7RII.

    1080 30p Fine on E-M1, 4K FF 24p 100Mb/s on A7RII. 

    Simple premiere edit to make the composite. No effects applied. I wanted to also compare to the warp stabilized A7RII version but only analyzing the 1.5' 4K video would take more than 30' and I would fall asleep before it was done (I now appreciate NX1's DIS a bit more, since can't imagine how much time it would take to analyze a 30' recording).   

    Keep in mind that the DoF is different since I wanted to compare the same ISOs under shitty light.  I might do another test in daylight and then the DoF will be controlled. Also the videos might seem unsynchronized but believe me they are. This is really the IBIS in action.  

    Hope it is useful for some of you... 

     

  2.  No plans on buying this camera anymore. Sony, no money for you! 

    Lastly, remember you said this when it's time to sell this thing. Can't see it keeping its value with overheating and the risk of damage to the sensor. Good luck!

    i am well aware  of this. Thats why I got it used for $2600. 

  3. It's a weak argument. And arguing this way will ensure that more companies put out substandard products. Gh4 doesn't overheat... Neither does Samsung. Over $3k gets you under 20 minutes in ideal conditions... Then what? Wait 10 minutes and be limited to 3-5 minute clips. If you are satisfied with that kind of performance, then you are mighty forgiving. I prefer cameras that can take abuse without skipping a beat. Clearly we have different standard.

    I am trying to defend Sony in any way, I am just stating the facts. I don't enjoy gear fights. Of course I would prefer a product that is perfect in every way. Its not about having a different standard but different needs, I need a compact camera with IBIS that shoots great quality video. Neither GH4 nor NX1 do that. Until there is another company that makes such a camera, A7rII appears to be the only choice, as crappy and expensive that might be. I am sure that when they find a way to solve the heat issue they will release yet another camera. Would you prefer not to have the A7rII at all until they solve the problem? From user reports the majority of them sound pretty happy and they definitely don't believe the camera is defective. I think that works well for both Sony and their customers. 

    Keep in mind that people had argued that:

    FF in compact was not possible (RX1, A7, A7r). 

    Then that proper quality video recording with FF in compact was not possible (A7s)

    Then that IBIS with FF in compact was not possible (A7II)

    Then that 4K with FF in compact was not possible (A7RII) 

    Then that long 4K recordings with FF in compact was not possible (wait for A7sII). 

    You have to give it to Sony for making it this far. You don't like Sony's products? I have a solution: Don't buy them! 

    There are always going to be limitations, with any product, we just have to work around them. 

    Now if I were a professional videographer, most probably I would not use the A7RII, but I doubt it was targeted to them anyways. 

  4. I would be very interested to see a test between a 0-255 -> then converted to 16-235 in the NLE  vs a 16-235 recording.

    Correct me if I'm wrong but when you export your editing (youtube, mp4, H264), you end up in a 16-235 color space right ? 

    Yes but in between there is a grading step. Its where the extra information might be useful for some people. 

    So the test would be 0-255 --> grading  (0-255 rgb space) --> 16-235 delivery  vs a 16-235 recording --> grading (0-255 rgb space) --> 16-235 delivery

  5. I can't understand your position. 

    The problem is that there is no hard limit that Sony could put in the manual since the usable limit depends on the shooting conditions.

    My point was this: Even if Sony decided to underestimate the length of the recording lets say 10 minutes max, people would still try to make the camera overheat and complain. 

    In general I agree with you, I prefer when companies/people come clean from the beginning. Or at least put an accessible thermometer inside as you propose. 

  6. Imho, defective is not the word, it's a limit of the camera. What's unacceptable is that it is not written black on white on the specs. Specs should report the minimum time you can expect to record without overheating problems.

    Because people would still put it in the oven and complain it overheats. Welcome to modern marketing (and politics by the way).  

    I also wonder how this whole overheating thing will affect the sensor and if the IQ will remain the same or if it will worsen with repeated use. 

    Me too.

  7. How much are we talking though? If I'm coming from a Fuji XT1 or a Canon 7D I'd expect a little bit, and that 'little bit' for me might be 'a lot' for people used to Full Frame sensors...?

    Well I can't tell you how much is too much since each one has its own thresholds. 

    Head over to the dpreview forums, there are plenty of examples so you can see if you can handle it. 

  8.  

    I'd be much more worried if this overheating issue applied to still photography on the other hand....does it?

    During long exposures it is not causing shutdowns but instead you end up with excessive noise and reduced dynamic range. 

    Exposures shorter than 10 second do not seem to have any problem. 

  9. I am between the 40 - 28 degrees (50-70mm range on FF)

    I found that most wide FoV lenses in MFT give me too much distortion. 

    Also since I cannot manipulate the scene that I shoot, I get the framing that I want much easier with the normal-telephoto range. 

    Now with the A7rii I will give the ~55 degrees another try. The nice thing is that it will also become a normal in the S35 mode. 

  10. I do the hard work in Resolve then just apply the LUTs and don't fiddle with anything afterwards. That makes for a much quicker edit. It is tempting to tune each shot isn't it? Shouldn't be necessary. A LUT can be consistent and give you the same look for everything. It also helps to use manual white balance. Most shots need tweaking due to the wrong colour temperature rather than the wrong exposure.

    Most of the time that should be the case. Manual WB and one LUT. Add a couple of global effects and you are done. Gives you more time to focus on the actual edit and sound. 

    Maybe very different light scenes will require a bit more tweaking but that should not be the rule. 

    I believe WB (temp & tint) is something that camera companies should make much easier to change on the fly. Its a big part of the picture and many rely on AWB. Which with some cameras works great but in others it is all over the place making colorgrading a marathon. 

  11. Ok, so for a 'video newby' like me, to check if I understood: both the settings keep the same data and map them in two different ranges (0-255 or 16-235). 

    the camera tries to fit the same data into two different ranges. But as soon as it puts them in the smaller range you loose some information. as you say there. are less discrete steps that might result in banding when grading. 

    as far as the lut I doubt there is a difference since the data are mapped in the 0-255 range and rgb space when you are in the nle program.

  12. With 16-235 I see more detail in the shadows.

    Premiere seems to take the 0-255 footage and clip it to 16-235, so you lose a ton of dynamic range.

    Since there is no way to directly edit H265 files in premiere and a transcoding step is required, did you try transcoding to H264 with the proper 0-255 range? Premiere should be able to handle 0-255 footage if the codec supports it. My understanding is that Prores is a broadcast coded that uses the limited range (16-235 for 8 bit). So the clipping either occurs when you transcode the H265 into Prores or when the prores actually uses the illegal values that are clipped then by Premiere. 

    The problem is that using the limited range 16-235 you are throwing away 1/3 of the space. 

     

  13. Don, this is great. Is there such a thing that factors in anamorphic? Recently when that Revenant trailer came out everyone was talking about the big 65mm sensor plus anamorphic whatever and how a 40mm was equiv to a 20mm or something and I was lost. I'd love to know how to do this. Thoughts or tips? Btw, I don't really have the desire to shoot anamorphic, but I'd love to know how to convert the FOV to reference some of my favorite movies.

    Its easy, just multiply the sensor width by the anamorphic extension (i.e. 1.3X, 2X...). 

    For example a 50mm on FF with a 2x adapter has a 72 deg FOV. 

  14. sorry all I see is reduced vibrations and jello.

    But it sounds like none of you have the camera. So let's all try and not stear the thread of topic and wait for someone that have it to confirm or deny the usability of the DIS. 

    Mattias, yes you are right I don't have the camera. But based on an example that shows that jello is still there: https://vimeo.com/136934126 my opinion to your provocative title is that no, I don't expect the DIS to "kill the A7rII". Especially when using lenses without OIS. 

    Let me elaborate a bit. 

    In principle even with the same rolling shutter (NX1 & A7rII S35) the IBIS is going to have less of a jello effect. 

    Digital image correction can be done in multiple ways. One is the stabilization for motion across frames like the wrap stabilizer of premiere. This can have adverse effects of unnatural image distortion. The other is within image correction of the rolling shutter effect. The last one can be done in two different ways: 1. Estimate the transformation from the rolling shutter across multiple frames (Premiere does this). This cannot really correct anything other than the constant angled distortion from a fast pan. 2. Use the true rolling shutter information & the information from a gyro to fix the transformation of the image caused by the rolling shutter (E-M1 presumably does this). 

    It is apparent from the attached footage that the NX1 DIS does not do the last part since most probably it does not have a gyro inside. 

    I don't know if the A7rII does that either but most probably the IBIS help with the jello, and adding a "slight" warp stabilizer in post will get you a more natural image.  

    Now I don't want to downplay the NX1 as a very nice camera, or the efforts from Samsung to improve an already unique product or the usability of the build in DIS in some circumstances. As I have said before, I just don't like "camera vs camera" threads. It would be better if the title was more in the lines of "NX1 keeps on getting better".

    P.S. I can't say I am not biased since I have the E-M1 and the A7rII is arriving next week :). 

  15. I love this idea Don. Can you teach me more about this? Or point me in the direction of a chart or something that references focal lengths to degrees? This would be super helpful. I hate the whole s35 or FF thing because it's so dang confusing. Throw in anamorphic and I'm totally lost. If I can get a reference for the degrees, I for one will start using degrees instead of focal, or at least use them together.

    I am glad you like it. 

    There is a simple formula: horizontal FOV = 2 * atan(0.5 * sensor width / focal length)

    But there are plenty of online calculators like this one: http://www.tawbaware.com/maxlyons/calc.htm

    Here are some on FF:

    20mm --> 84deg

    28mm --> 65deg

    35mm --> 54deg

    50mm --> 40deg

    85mm --> 24deg

     

  16. To my eye the example in your link shows that it massively reduces jello...

    Btw, in my experience stabilisation always reduces jello. What IS is it you have used that also has some sort of additional jello correction? Never heard of it before.

    It corrects the vibrations but not the jello. If you look closely the first video on that forum you will see that the DIS image is transformed and looks very unnatural. At this point you are better off doing it in post. 

    E-M1 tries to compensate for the rolling shutter and from my experience is very good at it. 

  17. It would be great if everybody used degrees for FOV instead of focal lengths. 

    50mm on FF ~ 40 degrees horizontally. 

    Then as the cheapest possible director's viewfinder, I have measured the angles between my fingers and I place my eye on the imaginary crossing line of the two fingers that are closer to the FOV that I want to achieve. 

     

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