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Marcello Mazzilli August 19th, 2016 05:38 AM

Using iPhone 6+/SE
 
I am building a portable setup for my iPhone to use as a second emergency camera.
Around is full of cases, lens addons, lights, etc... I found what suits me and I guess each of you found their own gimmick combination.

My question here is on the video quality of the iPhone.
The camera has a 4032x3024 resolution when making photos but when making videos the picture seems cropped (less wide-angle) so the real sensor resolution that is used is around 3400x or even less.
So.. what about 4K video?
Is there some interpolation here?
How much?
And what if I use the zoom feature in 4K mode? Even more interpolation!
And, if I keep in HD mode? Can I use the zoom with confidence until.. let's say 2.0x believeing that there will be no interpolation here?

I know there are differences between the actual sensor size and the photo file (4032x), and I know that seniors have built in some sort of interpolation (to create square pixels from single circle/hexagonal RGB cells)... but i'd like to know more...

Can somebody address me to REAL ACTUAL TECHNICAL DATA on the iphone camera?
What is the real sensor size? How is video extracted (cropped?) from the original picture? What happens with zoom? Etc...

Thanks, M

Gary Huff August 20th, 2016 07:57 AM

Re: Using iPhone 6+/SE
 
I would think the best solution would be to test different scenarios and see how you feel about the quality of the footage and go from there. At some point, testing is far a more worthwhile use of your time then perusing specs.

Marcello Mazzilli August 20th, 2016 07:58 AM

Re: Using iPhone 6+/SE
 
I am doing my tests... I also found apps that limit the zoom to crop without digital interpolation... but still.. I would like to have the specs

Gary Huff August 20th, 2016 07:59 AM

Re: Using iPhone 6+/SE
 
Takes less time to Google than to post.

Marcello Mazzilli August 20th, 2016 08:52 AM

Re: Using iPhone 6+/SE
 
Tried.. Can't find it

Donald McPherson August 20th, 2016 12:32 PM

Re: Using iPhone 6+/SE
 
Is there not something about variable frame rate that makes it awkward to edit?

Marcello Mazzilli August 20th, 2016 12:36 PM

Re: Using iPhone 6+/SE
 
Yes.. I am having some problems with that too.
For example if I shoot a slowmotion at 120 fps then in Premiere I expect to have 1200 frames for 10 seconds of shooting and I expect to be able in the clip properties (INTERPRET FOOTAGE) to set whatever framerate I want. Let's say I put 24fps I should have 24 DIFFERENT frames every second... but sometimes Premiere gives me two identical consecutive frames and I don't understand why.

The only explanation is that the iPhone couldn't keep up with the 120 fps and created artifical frames from the previous one, so actually jumpong frames. Again.. I'd like to have proper technical data on this.

Seems Apple is very good at hiding REAL TECH info

M

Craig Seeman August 23rd, 2016 10:06 AM

Re: Using iPhone 6+/SE
 
You may want to look into FimicPro
Not only a very professional video app but perhaps their support can tell you a bit about the phone specs which they must know to develop an app like this.

FiLMiC Pro - Mobile HD Video Camera for iPhone, iPad | App of the Year | Mobile HD Video Camera for iPhone, iPad | App of the Year

Marcello Mazzilli August 23rd, 2016 10:12 AM

Re: Using iPhone 6+/SE
 
I already use Filmic Pro as well as another few pro apps. I wrote to them and they are very kind. They replied all my emails... except this one asking tech info on how they implement the zoom (other apps have a limit to crop resolutions and no interpolation...and if you select it in 4K you get, correctly, no zoom at all).
I am not a developer but I think the pro app developers haven't full access to the sensor (like for example the Magic Lantern people that created the alternative firmware for Canon 5D). I think iPhone app developers have to stuck with what Apple passes them. At present, for iPhone, I couldn't find an app that has the following...

- RAW picture
- Flat colour settings
- Separate (truly) shutter controls (they seem to link to ISO and EXPOSURE, so you can't change them independently)... for video (in photo apps you can)

Gary Huff August 23rd, 2016 02:52 PM

Re: Using iPhone 6+/SE
 
Quote:

Originally Posted by Marcello Mazzilli (Post 1919783)
RAW picture

The iPhone currently does not have an API to allow raw image capture (raw is not an acronym). This is coming in iOS 10, but will require you to have the 6/6S, SE, or iPad Pro 9.7.

Quote:

Flat colour settings
There is no reason to have "flat" color settings. This is something that has to be built in at the imager level (essentially). Making an image "flat" after the fact means you're just adding back saturation and contrast that were already there to begin with and removed, thus stressing the codec and lowering the overall quality. If there is a Log gamma curve or color gamut, that will be built into the iOS and cannot simply be added by an app.

Quote:

Separate (truly) shutter controls (they seem to link to ISO and EXPOSURE, so you can't change them independently)... for video (in photo apps you can)
Apple has to provide the API for this. Not sure if that will be in 10 or not.

Marcello Mazzilli August 23rd, 2016 02:57 PM

Re: Using iPhone 6+/SE
 
Thank you Gary .. you seem well informed.

I know RAW just means raw and is not an acronym.. I just like using capital letters every now and then. R.A.W. would be how I write an acronym

I understand there are no APIs for shutter.. ok... let's hope for iOS10.

I don't completely understand your idea on the FLAT colours. I am not asking for a fake flat (first I have the colour, then I take it out etc..). What I was thinking (butI guess I am wrong) is that the chain should be

RAW -> FLAT -> CONTRASTED/COLOURED

So if RAW (full control on picture) is not available.. a FLAT (pre-treated) image might be.
Anyway.. Is great news to know that RAW will be available soon (iOS Beta is out already)

Are you informed also on resolution (real, interpolated, etc..) ?

Thanks, Marcello

Gary Huff August 23rd, 2016 03:01 PM

Re: Using iPhone 6+/SE
 
Quote:

Originally Posted by Marcello Mazzilli (Post 1919793)
What I was thinking (butI guess I am wrong) is that the chain should be

RAW -> FLAT -> CONTRASTED/COLOURED

So if RAW (full control on picture) is not available.. a FLAT (pre-treated) image might be.
Anyway.. Is great news to know that RAW will be available soon (iOS Beta is out already)

That's not how the chain works. The Sony FS raw setup (FS700, FS7, FS5) sends out a 12-bit raw signal with Slog2/3 and Sgamut/Sgamut3 built in. The C500/C300 Mark II raw outputs are also the same, with Clog/Clog2 baked in. It's a part of the upfront processing of what hits the sensor into the data stream that becomes the file you work with. It's either built-in or you're just faking it, and if you're just faking it, then you're stressing the codec that is the compression of said data (because you won't be getting raw video from the iPhone into a file format).

Marcello Mazzilli August 23rd, 2016 03:03 PM

Re: Using iPhone 6+/SE
 
I understand.
So you think iOS ill make RAW available to developers but not directly in the file for the users? Maybe some developer will make it so the file can be saved in a format with RAW info.

Any info about resolution and zoom?

thanks, M

Gary Huff August 23rd, 2016 03:07 PM

Re: Using iPhone 6+/SE
 
Quote:

Originally Posted by Marcello Mazzilli (Post 1919795)
So you think iOS ill make RAW available to developers but not directly in the file for the users?

With Lightroom for iOS, you will be able to take raw (not RAW, that still makes no sense. You get a .DNG or .ARW or .RW2 or .CRW) stills that will probably be a DNG file (which is an acronym that stands for Digital Negative). It does this on Android already.

This is for photographic stills.

Not for video.

Marcello Mazzilli August 23rd, 2016 03:15 PM

Re: Using iPhone 6+/SE
 
Thanks. Ok... I hope that if it is technically possible, some developer might do it for video too.


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