[I]" I'm doing my own research on the various formats and quickly learning that the price of a good Pro camera is not always the best way to determine it's value."[/I]

As far as I've seen for Sony it pretty much does although recently it's confusing as Sony are dropping the price point at which many features get added.

I've just seen the announcement of the PXW-X160 and if I had the money to spare I'd be very interested as the EX1 is getting a bit old and the G series lens with 25x zoom (650mm equivalent) would be better suited for shooting stage shows. The 100Mbps 10bit XAVC Intra recording seems a bit over the top though. Hopefully it'll have other choice that don't eat through memory cards so quickly.

Bob.

>> another advantage of 4K is the ability to crop

I would also add that another advantage of shooting 4K is that it is the perfect acquisition format for high quality 1080p delivery. Why? Well, look at the Panasonic GH4 for example. When shooting on SDHC cards, its acquisition format is 4K 8 bit 4:2:0. Drop that on a 1080p timeline and basically you will be editing 10 bit 4:4:4 video. That will give you spectacular results.

More here: http://www.eoshd.com/content/12140/discovery-4k-8bit-420-panasonic-gh4-converts-1080p-10bit-444

In other words, if you are delivering 1080p footage regularly, you should sell all your current gear and get a 4K acquisition system *now*, for example the GH4.

I have been looking at the GH4 and the Sony A7s, and for me, the GH4 seems to have some very significant advantages. Some are mentioned here, but I would also add that, with an external recorder, the GH4 can deliver 4K 10 bit 4:2:2 video. Considering the amazing quality of its 4K 8 bit 4:2:0 down sampled to 1080, starting out with 4K 10 bit 4:2:2 should yield even more spectacular results.

At the moment I think the GH4 is the one to beat, and it doesn't seem like anybody is wanting to compete. Yet. Apparently it sells like hot cakes and is difficult to keep in stock (as is the Panasonic 12-35 f/2.8 lens most people would get with it). I can understand that. From what I have seen, the GH4 blows the 5D iii with Magic Lantern RAW out of the water, even in low-light scenarios apparently. Seemingly it is a match (except for rolling shutter) for a Black Magic production camera too. Seems unlikely, but that's what "they" say.

Terje thanks for your input. Your work if simply amazing and inspiring.

I decide to get myself a DSLR for video and was wondering what to go for either the Sony A7s or the GH4. I wanted to go with the A7s because my other Alpha lenses would fit. adapters available for the GH4?

[I]" Well, look at the Panasonic GH4 for example. When shooting on SDHC cards, its acquisition format is 4K 8 bit 4:2:0. Drop that on a 1080p timeline and basically you will be editing 10 bit 4:4:4 video."[/I]

Read the article and I agree with the better chroma sampling, that's a long recognised advantage but the 8bit to 10bit claim I don't get and it's not explained either.

[I]" At the moment I think the GH4 is the one to beat, and it doesn't seem like anybody is wanting to compete."[/I]

The GH4 has a 16 megapixel MFT sensor up against sony's A7s with a 12 megapixel full frame sensor for an extra $800. I know I'd certainly spend the extra $800 in a heartbeat.

Bob.

>>>>>where the new A7S boasts a max ISO setting of 409,600<<<

I can get 1979 honda and put in an odometer that goes up to 200mph. Sony did the same there only instead of fake mph theirs says ISO.

Full frame vs. MFT sensor, not much difference

MFT lens options vs. Sony's choices and Sony's dependence on an external HD.. Huge difference right now.

A7 should sell for about $1000 because that is about what it's worth as a camera. I generally like Sony hardware, but I just don't feel it with this camera at its current price. By the way, Panasonic does have a full frame camera that shoots 4K for about $1000 or so. Don't know if it's out yet.

By the way, my 10 year old Canon HV20 ( which I haven't touched since 2010 ) shoots HD just as good as both of these. The only real advantage to these newer cameras is that they shoot better stills and finally can match HD video from a low end camcorders from 10 years ago. It's more convenient these days, but let us not get carried away with supposed quality of the footage. It's still just video and completely unsuitable if you want to get the "film" look ( in this context that means anything that can be shown in a theater or on a good TV without looking like a cheap indie movie ).

I'm sticking with GH2 for now. Don't see any real world/practical difference in quality. Unless you are a YouTube/Vimeo video test masturbator desperate for YouTube views trying to show off features no one will ever use it really makes no difference.

8bit 4k to 10bit 2k can be simply explained with basic math. Take 4 pixels 8-bit data (0-256) and combining all the values into one downsampled pixel is 10-bit (1024). But it is just an average of chroma values and doesn't offer any real visible advantage.

10-bit luma is the real improvement, not so much chroma, based on what I have seen and read.

Deusx, your HV20 shoots video as well as the A7s? You must have one really special HV20.

+1 jc - deusx, if your hv20 shoots as well as a dslr then you've got the only one in the world that does so.....

If I uploaded some HV20 HD video to TouTube or Vimeo and told everybody that it was from A7s nobody would doubt me. You could not tell the difference.

How many of you have actually held A7s and GH4 in your hands and watched files from those ( not YouTube or Vimeo uploads, but actual files? ).

I have done both and I see no reason to not continue using GH2.
I'm not a pervert who sneaks around the neighborhood in the dark, so I don't need higher ISO. Don't do much green screen work these days which is one area where these 4K files may do better. But showing you a normally shot video from GH4, GH2, A7s or HV20 on a HD TV or somewhere on the internet you would have no clue which is which. Nobody would.

"I'm not a pervert who sneaks around the neighborhood in the dark"

That isn't at all the point of being able to shoot noise-free video at an unusually high ISO, it allows you to use much more dramatic lighting using less powerful LED fixtures and practical lighting. Something an HV20 simply cannot do.

I'm playing with new RX100M3. Full sensor readout immediately and dramatically noticeable compared to predecessor...very excited about A7S.

don't know about the A7, but I also have an HV20 and did a side by side with my Canon T3i - nearly ZERO difference. Thus, HV20 looks as good as COMMON DSLR, just different. And the HV20 had much less noticable MOIRE!!!
I attribute this to Canon lieing about their HD: where 1080 is more like 600 ACTUAL lines of resolution.
The T3i has way more manual functions and lens options, but image quality is identical believe it or not.

It is no way identical.

It is that some eyes can not see the differences.

The real difference, easily noticeable, will be low light noise.

I can post up image comparisons. I was shocked and disappointed the T3i looked no better than HV20. The biggest difference I noticed (other than coloration difference easily adjusted in post) was the LESS MOIRE in the HV20.

Yes, DSLRs have moire issues and the A7s is no different. What the A7s does have is close to 14 stops of dynamic range.

[I]"Yes, DSLRs have moire issues and the A7s is no different"[/I]

I would anticipate that the A7s would have less issues with moiré and aliasing than the A7 and less again than the A7r because the sensor resolution matches the resolution of the target recording.

Bob.

It remains to be seen how exactly the 7S will perform, but based on what I'm seeing with the RX100 Mark III (which uses similar tech), it's going to be stunning...

S-log2 3200iso gimp is newly imposed by Sony and stopping my purchase.

I would think the Sasquatch hunters would be interested in this type of camera.

>>>The real difference, easily noticeable, will be low light noise.<<<

Not if you know how to light your scene which even 1/4 pros should know.
You will notice absolutely nothing I can guarantee you that. This is the exact same bull$hit we went through with more megapixels = better. Just marketing.

Didn't we have shootouts which concluded that GH2 was as good or better than Red and Arri cameras? I mean seriously, it's all bull$it perpetuated by people who want to attract viewers to their blogs. And in normal lighting conditions my GH2 looks no better than my HV20, absolutely does not, so am I to conclude that HV20 is as good as Arri?

Then GH4 and A7s should sell for $500000000 since they are so much better than GH2, right? Seriously, let's calm down a bit. It's just another camera.

"You will notice absolutely nothing I can guarantee you that."

There is a trend in cinema these days to use less light for more dramatic effect, this was not possible until the advent of high-sensitivity digital cameras with low noise. Read some interviews with the DP of the highly regarded "House of Cards" series on Netflix, for example. One is no longer limited to "normal lighting conditions", it is now possible to get clean, nicely lit, low light shots with good contrast. What the A7s brings to the table is being able to do this with 15.3-stops of dynamic range much less expensively. Apparently, you can't appreciate the potential so it's probably best that you just stick with your HV20.

"I would anticipate that the A7s would have less issues with moiré and aliasing than the A7 and less again than the A7r because the sensor resolution matches the resolution of the target recording.

Bob (farss), I stand corrected, you're absolutely right. The A7s' "direct pixel readout" utilizes the entire width of the full-frame image sensor without line skipping or pixel binning essentially eliminating moiré and aliasing.