Michael1

Andrew, thank you for the comparison test.  It's always great to see how cameras perform next to each other.

Someone please help me out here.  I am looking at the dynamic range test, but am not seeing what variable is fixed for comparison purposes.  The Sony's sky is a bright, vibrant blue compared to the washed out 5DMkIII, but the shadows are much darker than those of the 5DMkIII.  In fact, the tree goes to black on the Sony, while I see green in the 5DIII tree image.  If the 5DMkIII was exposed that dark, would the sky saturation come back?  If the tree had more exposure on the Sony, would the sky turn pale?

GH4 was awesome in the resolution test at 4K.  It was as if a veil had been removed.  Like to see additional GH4 comparisons.  a7S vs. GH4 seems to be on everyone's mind these days.

Enjoy these reviews.  Looking forward to Part 2.  

Michael

There are only 5 SONY lenses so far but there are also the Samyang/Rokinon lenses in full frame E mount and there is also the Mitakon 50 f0.95 in full frame E mount.    So closer to around 10 native lenses with more coming.    The LA adapters are considered by Sony as native part of the system too I think, adds to the cost, yes but if someone has a few A mount lenses then it would well be worth getting an LA-EA4 maybe.

 

I like using FD L lenses on my normal A7 and think they would be very nice on the A7s for both video and stills.

It's actually worse than I thought.  There are only two FE lenses with optical image stabilization.

Michael

When you guys see these spots are they always in the same location, even after changing lenses?

Michael

DxO is completely irrelevant for video shooters. Unless you are shooting Magic Lantern Raw. Yes, it might give a suggestion of the capabilities, but it all depends on the internal processing of the raw data, so it can get either worse or better than the DxO results.

 

Also, I'd take the Techradar results with a grain of salt. I often see results in their graphs that are completely different from other lab tests.

 

Like this one. Look at GH4 dynamic range in raw, I wish it was that good! No way it has between 13-11 stops over the whole iso 100 - 25.600 range.

 

 

DxO looks much more reliably to me if you look at the DR measurements: http://www.dxomark.com/Cameras/Panasonic/Lumix-DMC-GH4---Measurements

I about fell off my chair when I saw this Tech Radar chart with the GH4 being up there.  Based on other graphs I found, it looks like it is blowing every other camera out of the water, including the D600, D800, 5DMk3.  I wish it was true, but I'm not believing this.

Michael

These tests of the A7S show how the internal processing on the A7S in Jpeg (and presumably video), is rather complex. Comparing RAW images for noise and dynamic range among other things may not be suitable. I feel the colours have been muted slightly, but that has somehow pushed the Dynamic Range across the various ISO settings. I feel DXO labs did not conduct their tests accurately. I could be wrong. It's jusr my opinion.

http://m.techradar.com/reviews/cameras-and-camcorders/cameras/digital-slrs-hybrids/sony-a7s-1255921/review?src=rss&attr=all

I don't think I understand why you think they made mistakes for the a7S, or somehow the tests are wrong only for the a7S.  If you don't do the same tests for all cameras, then you don't have anything.

Michael

I agree with Ebrahim. No point of reference so can't really say if they're good or bad. I will say it looks fairly realistic. Though, being Chinese, I'm less fussy than most others in this forum about yellow hues and such.. If anything there is too much magenta; but that's probably just down to lighting.

I saw an a7S comparison test (to other cameras such as the 5dMkIII and D800) where even Asian complexions looked too yellow.

Michael

Lot of magenta in the first shot (interview).  The audience has a lot of magenta.  Was that the lighting there?

Michael

Nice work!  What kind of masking were you doing for this?

The shopping scene looks familiar.  Beverly Hills?

That's blond is knockout BTW. :)

Michael

The gamma issue between Mac and PC has been a problem in the film industry for decades -- especially in terms of the QuickTime 7 system framework, which has been deprecated.

 

Unfortunately, media applications on these two disparate computing platforms *do not* read the file-based gamma data and compensate accordingly.

 

And aside from file-based gamma differences, you also have issues surrounding the calibration (or not) of the user's display.

 

Color grading is very definitely a subjective art, but I can tell you that I would never let the image at the top of this thread out my door -- unless of course, it was an intentional stylistic decision.

 

On a somewhat related topic, it is interesting to note the number of comments on the Internet questioning the color science of the A7s.  Interestingly, when that color science has been called into question, I have found myself in general agreement after watching the clips on my calibrated monitor.

 

However, it's hard to know if these issues are related to computing platform gamma differences -- or users posting S-Log2 footage on Vimeo (or an alternate picture profile) -- without having pulled it back down to Rec. 709 or Rec. 2020. 

Does any camera support Rec. 2020 yet?  That's a much wider color gamut.

Michael

I'm interested in hearing what turns up here for full frame shooting.  In looking at the Sony FE lenses there are still only a total of only five, count 'em five!  I thought Sony was going to start cranking out more lenses.  Other than the "kit lens", they are expensive, too.  While the performance is great, they are overkill for video.  In fact, they are overkill for the 12MP sensor.

So then you have the adapters...(more money, more clutter)

http://briansmith.com/sony-a7-a7r-lens-mount-adapters/

Looks to me that only the Canon lenses are really supported for auto focus and aperture, but it doesn't look like distortion, chromatic aberration, or vignetting correction is supported.

Michael

But you make me doubt about my vision because you saying nothing is wrong with the clip.. Is a i7 machine with 8gb ram not fast/good enough for playing C4K?

 

No, it's not.  You need a video card with a good GPU (lower end cars won't cut it), and playback software that supports GPU acceleration.  You also can't use an old video card, no matter how fast It is, that doesn't support the latest version of DirectX.

Michael

The a7s and RED cameras both produce images as sharp as the GH4. I know they're several times more expensive, but it still demonstrates that a technically good video image can be attained with larger sensors.

 

 

What resolution test are you using to make this statement?  Since the GH4 produces 1100 lines of resolution in 4K, that puts it just out of reach for any 1080 camera.

Michael

 

"Shooting movie footage on a camera as powerful as the D810 is an enriching and liberating experience. Surpassing the video quality of its predecessors, the D810 employs an entirely new method of video signal processing to record Full HD (1080p) movies at 50p/60p frame rates  with markedly reduced noise, moiré, and false colour. The camera’s EXPEED 4 image- processing engine delivers smoothly rendered exposure transitions and beautiful tones"

-Nikon  :rolleyes:

 

I know you are rolling your eyes, BUT AFAIK, Nikon was the first to virtually eliminate moire', and aliasing while still retaining image detail using onboard camera image processing.

Michael

I have to admit I cringe when I read about fixing a problem by running a full frame camera in crop mode, and then fixing the crop mode "problem" with a SpeedBooster. :D

Michael

If you look at the financial statements for Nikon, you'll see they are actually doing surprisingly well.  Their peak sales were last year, and this year's sales are only down 2%, but their profit is up 15%.  You would think by reading  posts on the web that Nikon is on the brink of bankruptcy.  Nothing could be further from the truth.

Michael

Here's one.  Appears to be a GH4 promo short.

https://www.youtube.com/watch?v=5niWpEJQxJkc

Here is the "Behind the Scenes" for the short.

http://vidhouse.co.uk/video/O8PP9uYHqk8/Behind-the-scenes-of-GH4-short-film-Dalia-s-Dream.html

Probably not the best example of what could be done.  It seems to have a '70's look to it, which maybe is what they were after.  In fact, they should have put the credits in yellow. :)

Michael

Well I just had a great experience at Panasonic in Newark regarding my issue with the micro hdmi. The head engineer contacted me regarding this issue. They actively monitor sites like this for customer problems and reached out to me. Nice right? Anyway, it seems the connector port on my two bodies were VERY tight. At first He had to push pretty forcefully to initiate contact. Now that its been in once, it goes in easily... Just the way one should expect it to.

 

  I had a number of my colleagues try it as well as sales people at BH . No one wanted to apply the amount of pressure needed to make contact for fear of damaging the connection. Clearly it was too tight , but now...no problem. 

 

FYI, Id like to thank the head engineer who was so engaged and helpful. He asked me not to mention his name. Aside from solving my issue, I got a mini tour of their headquarters in Newark and got some insight into the momentum the gh4 is gaining and the future of mirrorless in general.I also learned that theres a new verb bouncing around Hollywood..."Lumix it!" 

Thanks Panasonic:)

I've got to say, I'm impressed with the way Panasonic is actively involved with customers and addressing issues.  It seems like they really want to be tops in this market.

Michael

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

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? 

 

“Accordingly, the photographer has no way to detect that he/she has not benefited from the increase of light transmitted. Of course this increase in ISO translates into other downfalls – mainly in accrued noise. But these remain unknown to the operator,

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

Michael

Nice tutorial.  What have you been doing regarding the yellowish skin tones?

Michael

Here's another wonderfully done no-budget short that hasn't gotten nearly enough views: 

 

Nice short, but if it was done by Kendy Ty, the credits would have been him, the actor, and that's it.  That's one thing that is so impressive about him.  When other directors yell out, "Lights, camera, action!", Kendy only yells out "Action!".  There are no lights, and the camera is in his hands. :)

Michael

Hi Michael.  The pixels are made larger on the a7S to be more sensitive/accurate to light (especially low light).  This has little to do with processing speed.  If the camera has a problem it's that it can't save internal 4K.  The drawback of larger pixels is less resolution for still photos.  There is no drawback for 4K full-frame video--only positives (AFAIK).  You should also know that there is space on a sensor between each pixel, space that can't be used to read light and space which creates aliasing issues.  

 

As for color science.  White balance is so difficult to get perfect without expensive equipment that it's really impossible to factor out user error.  Even on my own somewhat calibrated monitors each video looks different.   For properly exposed video, I believe all the manufacturers end up with the same values.  Even if a camera has a certain "color cast" you should be able to adjust for it.   I'm no expert in color grading, but haven't heard it a problem for anyone.  Dynamic range or bit-depth is another thing.

Hi Maxonics,

The reason I say that the direction will be to more pixels again, is because as time has gone on, low light performance has improved, even as pixels have shrunk in size.  Right now the 1:1 pixel mapping used for 4K, is really just mapping pixels which are sensitive to one color to a pixel on the screen represented by a red, a green, and a blue pixel (excluding color subsampling).  The ideal case is a set of RGB pixels per pixel of resolution for maximum color fidelity, similar to what is done on 3-chip cameras.  In addition, I think DSLR cameras (vs. dedicated video cameras), will always be under pressure to perform well as a still camera, and that means high pixel counts.  Sony is really pushing the limits of creating a video camera in a DSLR type body.

Also there is the issue of hot and dead pixels.  It is easier to cover those up with more pixels to work with.  I saw one test where the a7S had a lot of (big) hot pixels if the noise reduction was off, way more than they saw on the a7R.

I am no expert, but I would be surprised if you could fix the bad color science I am seeing by just tweaking white balance.  White balance adjustment would shift all colors, but from what I see not all colors need shifting.

Michael

Got to hand it to Panasonic, they really take these issues and the GH4 seriously.  That was fast!  They are going for blood. :)

Michael

I see the low pixel count sensors as a temporary phenomenon.  I believe pixel count will rise again in hybrid DSLRs as CMOS read speeds increase, and processing power increases, as they naturally do over time.

What is concerning regarding the a7S is the color science.  I have been using comparison tools at various websites  The a7S colors are just off.  It's particularly noticeable on flesh tones.  The a7S has a strong greenish-yellowish cast, that makes people look like they have Jaundice.  The Canon 5DMkIII seems pretty much on target, and the Nikon D610 and D800 are close with a slight magenta cast.  The Panasonic GH4 also tends towards a yellowish cast, but it is subtle.  These results seem to align well with what I have seen in videos.

Michael

 I still haven't seen ANY footage from the A7S that looks really convincing in terms of colour.

 

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