Sony a7iv feedback

ahalpert said:
How far would you feel comfortable raising the ISO, Chris? And how do you think its high-iso performance compares to other sony cameras? Thank you
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Hmm! Depends on the subject matter and light levels. Up to 12800, I think I could use it in a lot of cases without having to resort to NR in post. Even at 25000, I have been surprised at how well the image holds up. Though I probably would use a light Neat Video on it if I wanted the best presentation. I prefer Neat to Resolve's NR as Resolve's seems quite crude at higher noise levels compared to Neat Video's processing.

Against other cameras? Again that's a hard choice as many of today's cameras perform well beyond anything we could have dreamed of a few years back. The other day out of curiosity we had the s7iv up against an a7siii and an FX6. This was purely a subjective visual observation as we didn't do any 'clinical' file comparisons. On a 50" screen I and the other two observers felt that between ISO 3200 to 12800 the a7iv looked quieter than either the FX6 or the a7sii. Also, a bit sharper looking using the same glass. A Sony FE 16-35mm F2.8 GM which we felt was a fair lens to use on all cameras so that we were comparing apples with apples. I feel the perceived sharpness boost is coming from the fact that the a7iv is downsampling from 7K in FF and 4.6K in APSC crop mode. The a7iv looking a little quieter in that 3200 to 12800 range didn't surprise me as the a7siii doesn't really step into its second stage ISO range until 12800 whereas the a7iv's second stage ISO kicks in at ISO 3200. In a real-world situation, I would be quite happy to use any one of the three cameras. As you push well above the 12800 range then the a7siii and FX6 start to show the benefit of their larger photosites. 8.4 µm pixels for the a7siii and FX6 with their 12 Megapixel sensors vs 5.1 μm for the 32.7 Megapixel sensor in the a7iv.

Where the a7siii and FX6 shine is in their rolling shutter figures coming in at 8.7ms which is outstanding. Compared to the a7iv in FF at 26.8ms which is in the order of 3 x slower that's enormous. I was aware of this possible issue when I decided I'd wait for the a7iv hoping it would have 4K 50/60. I fully expected that to be in crop mode only as it was rumoured to be a 33 Megapixel BSI non-stacked sensor. I rarely shoot anything under 50p where the rolling shutter on the a7iv comes in at 12.8ms which I can live with. The FS7 rolls in at just on 14ms and that has not proved to be an issue for me so I felt pretty safe with anything under that 14ms mark.

Final observation. CineD is stating 12.9 stops range on the a7iv as opposed to 11.9 stops range on the a7siii. I can't comment directly on that as I haven't had the opportunity to push the a7siii or FX6 to the extremes. All I can say is to date I haven't used any camera under the $5K mark that displays the dynamic range I'm seeing on the a7iv. For a $2500 camera, it's pretty impressive. I may even get a second one. Have to convince 'her indoors' before I take that step though :)

Chris Young
 
It looks like CineD measured the A7SIII at 12.4 stops DR, not 11.9? Nevertheless, a half-stop better than the A7SIII, and with supposedly less aggressive noise reduction at base ISO setting, is impressive. I do wish the camera had a faster rolling shutter and, relatedly, 4K60p uncropped. I suppose we all do! Still, it's high on my radar...
 
ahalpert said:
It looks like CineD measured the A7SIII at 12.4 stops DR, not 11.9? Nevertheless.
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Sorry A, I should have been more specific. I always tend to take note of the SNR=2 results at the higher second step ISO when looking at low light capable cameras. CineD quoted it as follows:

"IMATEST dynamic range reading of the Sony a7S III at ISO 12800 (native) in SLOG3 / SGamut3.Cine in UHD 25p mode: a solid 12.1 stops are calculated."

and

IMATEST calculates 11.9 stops at SNR = 2, which is really amazing for ISO 16000. So you lose very little going from ISO 640 to ISO 16000.

Basically, they say:

"Dynamic Range of the Sony a7S III at ISO 640 SLOG3 SGamut3.Cine. IMATEST calculates the signal to noise threshold value of 2 at 12.4 stops – a very good result but this has to be put into perspective."

My take on that perspective is who is going to shoot low light using S-LOG3 at ISO640? Not many I would suggest. The big appeal of the a7siii is its low light capability. That's one of the camera's key selling points. At ISO16000, which is a very useable setting on the a7siii CineD are stating that it is pulling 11.9 stops. More than ample in most low light situations.

If experience has taught me anything total dynamic range is a bit academic in many situations. Usually when working indoors with much lower dynamic range situations. Most modern cameras can deliver more than ample dynamic range in those conditions. IMHO what is far more important in low light shooting is what latitude do you have to play with if and when you have to recover certain parts of an image if it's under or overexposed. Especially underexposed because you are usually shooting to protect highlights. Or I am at least. CineD again on the a7siii.

"At four stops of underexposure, brought back to zero the limit of usability is reached. While the colors and image detail are still largely there, ugly blocky chroma noise artefacts are appearing".

re the a7iv

"Now, at 4 stops underexposure, things get interesting as all of a sudden quite some luma & chroma noise starts to show. Also, the image gets a slight pinkish tint this time. But still, all is good. Of course, you can further reduce the noise in postproduction if you like."

Virtually nothing to choose between the two models.

Both dynamic range and latitude are important. Learning in film latitude was nearly always our guiding parameter. You lit your sets or shielded extreme light sources to try to extract the levels that gave you your best use of the latitude of the film you were using. Not always possible but that's what you aimed for.

For me, from a purely practical point of view, the advantage of the 50/60p crop was that most of my lenses are S35 or APSC. These are generally smaller and lighter which also works for me. I also have FF primes and can still use them on the crop using a Meatbones Speed Booster a la FS7. Thereby retaining most of the FF look and DOF plus picking up that extra stop of light. A crop sensor has never been an issue for me as I've worked in S35 film and worked with S35 video for so long it's second nature. I also shoot production stills at times and the 33 Megapixel FF had definite appeal. The a7iv is a good "Hybrid" and that's exactly where it was aimed. Its hybrid characteristics and crop 50/60p are what finally tipped me towards it.

I came very close to getting the a7siii but the advantages of lens selection with my lenses made me hang out to see if the a7iv would do the crop 50/60p. I can even use the crop ClearImage at 1.4 x in conjunction with MTF's optical adapter and use a broadcast B4 lens in either HD or 4K if I need that kind of reach. I do not have that flexibility with a pure FF camera. That's also why I have steered clear of the FX6. If I move on from the FS7, which I'm tempted to do it will be to an FX9 as it offers me that 4K crop capability and a wider choice of glass. Plus the benefits of FF in certain cases.

Chris Young
 
Well now, that's cheating! Comparing the a7iv at low-base ISO to the a7siii at high-base ISO. One ought to compare them at the same ISO, no? And the high-base for the a7siii is 12800, not 16000. I get your meaning on measuring a low-light camera at its high-base ISO. Nevertheless, I shoot the a7siii at ISO 640 probably 60% or 75% of the time. Its performance there is very relevant!

I would also think that you'll get worse figures measuring the a7iv in crop mode since crop mode enlarges the noise.

Nevertheless, it's an impressive performance in both dynamic range and latitude for the a7iv and I'm definitely considering getting one. 60p uncropped and a faster readout and my order would be placed already. I'm sort of waiting to see if they'll release an APS-C camera with similar performance to the a7iv in crop mode. But at the back of my mind, I think that the a7iv would be the better choice for my 3rd Sony mirrorless camera anyway because 24p uncropped would be very useful and I would use it mostly in low-movement scenarios anyway (like a locked-off wide shot).

Thank you for all the helpful hands-on info, Chris!

Best,
Abe
 
Abe. Ah yes agreed. You would be using the base of 640 most of the time in decent lighting conditions. I went with the 16000 as that was what CineD referred to. They later corrected that comment to reflect the 12800 level. What I was getting at, probably not explained too well was to get the best out of the a7siii in low light where an ISO range of say 8000 - 10000 would work nicely you are better jumping to 12800 as the a7siii is significantly quieter when you hit that 12800. (12800 which I outlined in the previous post with the CineD quote.) That's where just observationally, subjectively we found the a7iv to be quieter in that very useable 8-10000 ISO range, even between 6400 and 10000 really. As I also pointed out previously above the 12800 threshold is where a7siii really shows its legs. But when comparing 8000 with 8000 and 10000 with 10000 the a7siii does exhibit more noise, especially in darker regions of the image. Which makes it harder to recover. Having that second ISO jump with the lower noise levels being at 3200 in the a7iv is definitely a big help in this regard.

One only has to look at the Noise (% of max pixel level) figures to see that. At -3 stops, hopefully not having to recover too much too often from that much underexposure the a7siii is showing noise levels of just about 0.75% of pixel signal level. That's low. But considerably lower at -3 stops underexposure the a7iv noise as a percentage of pixel-level is sitting at about 0.22%. That's a good two-thirds less noise vis-a-vis pixel signal level. On evenly well-exposed shots these figures become pretty irrelevant. Let me pose a scenario though. In a lot of high dynamic range low light scenes where you have large areas of low light with extremely bright practical source lights scattered through it, such as a dim nighttime street scene, darkness everywhere but with street lamps, car headlights, neon signs etc being your high-level practical light sources what do you expose for? Generally, you will try to protect the extreme highlights, which are generally the practicals if they are important to your scene.

In post, it's a lot easier to recover detail in those darker underexposed areas of a scene if the camera's SNR is reasonably decent. A case in point. One scene that I was called for was a shot of somebody looking out of a window from a brightly lit room on a rainy night. The main character in the window was what was exposed for. Yet we didn't want the visible parts of the exterior to be totally black when the shot was processed. The director wanted ambient light only. No extra external lighting! In that case. Being able to recover detail in those underexposed exterior parts would have been easier with a camera with a better SNR in the lower parts of its exposure range. The a7iv's pretty decent SNR in those sorts of scenes is definitely a step in the right direction as recovering detail in the lower light regions is easier as fewer noise artifacts appear.

I'll leave it at that. For observers who want to find out more, It's all there at CineD. Their RMS noise tables show the effect pixel noise can have on dynamic range. Especially at the higher end. 7.38 stops vs 9.11 stops. At those levels, it starts to become quite noticeable to the human eye. From our brief observations, the a7iv still appeared quieter in crop mode at those 8-10000 ISO levels against the a7siii between 8-10000. Probably because it is doing a 4.6K downsample. Downsampling done correctly nearly always helps in reducing noise levels.

Enjoy chewing the fat in the cause of enlightenment. Stay well Abe!

Chris Young

a7sii+a7iv.jpg
 
cyvideo said:
In a lot of high dynamic range low light scenes where you have large areas of low light with extremely bright practical source lights scattered through it, such as a dim nighttime street scene, darkness everywhere but with street lamps, car headlights, neon signs etc being your high-level practical li
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This is true, and I will readily admit that I have basically given up on protecting highlights with the a7siii in the aforementioned scenario because of the deleterious impact that underexposing has on the more important stuff in the shadows. In other words, I'd rather give the people a boost and get them away from the noise floor at the expense of clipping the practicals because it's true that I'm not happy with how well the camera recovers the shadows. It's not the end of the world. I try to find a nice place to clip the highlights so it lookss natural. But the camera does not give me everything I want.

But it sounds like for the a7iv to save me, I'd have to be in the ISO 3200-6400 range. My preference, from trial and error, is to push a sensor only about a stop above the base ISO, or at least the high base ISO. I don't really like the a7siii above ISO 25600. I use it between 12800 and 25600 and then between 640 and maybe 5000 or even less. It definitely starts to get dodgy at 3200.

There are definitely low-light scenes where I could be at 3200-6400, but a lot of the really desperately dimly lit doc/event interiors are up in that 12800-25600 range, especially if I'm shooting 60p and want 1/120 shutter.

Nevertheless, I like what I'm hearing and seeing about the a7iv DR and latitude and detail. It could definitely be a nice option to have in my arsenal!
 
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Understand where you are coming from. For shooting it as it happens what you are doing exposing for the important areas, namely, the people is where it is at and the highlights have to look after themselves.

BTW. Like your footer:)

Chris Young
 
Indeed! But at ISO 640 I've got enough range and recoverability that usually I can keep my cloud detail, underexpose the people and get them back without any issues. It would be awesome to have that latitude at 3200. And as far as DR goes in well-lit scenarios, the only time I'm hurting is sun in frame or, more likely since blowing out the sun isn't the end of the world, beautiful back-lit clouds at dusk plus people in frame without fill. The camera is almost there but just so slightly out of reach to keep all that in the comfort zone. It sounds like the a7iv might have enough for that situation
 
Well, you talked me into it, Chris! I just ordered an a7iv. On top of the surprisingly strong IQ fundamentals, I thought about my other current and potential options. I want to spend less than the cost of an a7siii, so the a1 and possible a7rV are out. An aps-c camera would work, but I'd miss the full-frame format for locked-off wides. My 24mm is no longer 24. Speedboosting means bringing extra non-E lenses and losing AF. I only really need 4k60p in crop format anyway as a de facto teleconverter on my 70-180 since I can get FF 4k60 on my a7siii and fx3.

I'll probably not receive my unit for 6+ months, but I'm excited. And with 3 4K Sony mirrorless + FS7, I'll sell my gh5 and gh4 plus probably also my c300 and 5dmk3 and most of my EF lenses. Even at pennies on the dollar, they should cover the a7iv. 3 cameras with matching batteries and lenses and largely matching color = bliss

Thanks for all the hands-on info!
 
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For one man bands, matching cameras are.the shizzle. Saves so much time and offers flexibility knowing whatever route you choose, the look will be there.
 
Just before going live. A quick HD sample from the a7iv. XAVC 50p 422 10-bit shot with the cheap and cheerful Sony 10-18mm f/4.0 OSS.

Chris Young

 
Another a7iv test that's come about as it was a lazy holiday break day. Wanted to see how Sony's HLG2 2020 would come across to Rec 709 using Resolve's Color Space & Transform. It offers a pretty reasonable result and squeezes a lot of the HLG dynamic range into a pretty respectable looking 709 image. Again a nice strong sunlit day with good deep shadows to pull detail out of is always a good test for most cameras. The lenses used were the 28-135 F/4.0 G OSS in FF and the Tamron 18-300 in the APSC crop mode. All shot in XAVC-S 50p 422 10-bit at 125 ISO.

Chris Young

 
wow my a7iv already shipped and is arriving tomorrow. sony must have really stockpiled units before the announcement! I put my order in just 2 weeks ago. With the a7siii, if you didn't pre-order it then you had to wait 6+ months to get one
 
ahalpert said:
wow my a7iv already shipped and is arriving tomorrow. sony must have really stockpiled units before the announcement! I put my order in just 2 weeks ago. With the a7siii, if you didn't pre-order it then you had to wait 6+ months to get one
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A similar situation down under I've heard. Apparently, someone heard a comment from a Sony rep saying because the a7iv is aimed as much at photographers as video shooters it was felt it would appeal to a much wider market segment so aimed for a much larger initial launch. I can sort of understand that reasoning, kinda' makes sense.

Chris Young
 
A funny thing happened with my a7iv last night. I was rolling 4k60/24 s&q in s-i codec when my cfexpress card filled up. The camera threw an error, I can't remember if it was that the card was full or that my other card was too slow. But it seemed to keep recording without stopping in the same settings onto the v90 SD card I had in the 2nd slot. After a couple minutes, I stopped recording and reviewed the clip to see if it was actually 24p instead of 60/24 slow mo. Nope, it was slow mo (and the file size later confirmed the bitrate). But then I pressed record again and the camera refused to record in that setting on the SD card. (V90 should be able to at least 720Mbps whereas this codec is only 600Mbps.) Sony has really screwed us media-wise with the cripple hammer
 
ahalpert said:
A funny thing happened with my a7iv last night. I was rolling 4k60/24 s&q in s-i codec when my cfexpress card filled up. The camera threw an error, I can't remember if it was that the card was full or that my other card was too slow. But it seemed to keep recording without stopping in the same settings onto the v90 SD card I had in the 2nd slot. After a couple minutes, I stopped recording and reviewed the clip to see if it was actually 24p instead of 60/24 slow mo. Nope, it was slow mo (and the file size later confirmed the bitrate). But then I pressed record again and the camera refused to record in that setting on the SD card. (V90 should be able to at least 720Mbps whereas this codec is only 600Mbps.) Sony has really screwed us media-wise with the cripple hammer
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It's very frustrating. I have a bunch of 128GB Sandisk Extreme Pro SDs that recorded 400Mbps 4k material from the XT-3 without ever missing a beat. Ask the A7iv or FX3 to record 250Mbps 25p material to them though? The cameras point-blank refuse to do so.

Interesting that you can technically bypass the lock-out, by having the camera roll-over on to a new card.
 
In video I can have autofocus with peaking on but I can't find this when taking stills. I mean when I half press shutter button I can't see if my subject is in focus or not with peaking. Is this possible? Or another tip?
 
BONLEV said:
In video I can have autofocus with peaking on but I can't find this when taking stills. I mean when I half press shutter button I can't see if my subject is in focus or not with peaking. Is this possible? Or another tip?
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In stills, select the DMF (Direct Manual Focus) focus mode in your Focus Mode settings. This allows autofocus in the normal manner but allows you to manually override the AF should you wish to do so. In this DMF mode when you half depress the shutter button it will autofocus in the normal manner but the peaking if turned on will immediately light up once focus is found. Now if you wish to fine tune the focus or select a different point in the frame you can manually roll the focus to achieve that correction/adjustment.

Edit: Forgot to mention. While depressing the shutter button for AF if you manually rotate the focus ring, the camera will jump into the magnified focus mode for critical manual focusing with peaking.

Chris Young
 
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