Sony Nex-7 video settings.

[Photon-hunter]

Hi all.I am trying to shoot some video for a personal project with the Nex-7. I have a European version of the camera , so my camera does 50p/50i.
When trying to record HD there is a plethora of settings that I am trying to understand. First there is the choice of MP4 or AVCHD. I don´t really understand the difference (else that my Mac won´t read/edit the AVCHD files unless I convert them).

Should I decide to shoot in AVCHD, then the number of options (for a video ignorant as myself) is a bit overwhelming. I don´t even really know what is the difference between 25/50i & 25/50p. Then there is a large number of options for both 50i and 50p (where the difference seems to be the file size or bit rate).I am lost. Something inside me says, "shoot the highest setting (50p 28M - PS) and then worry about converting after", but this may very well be a wrong approach..

I want to edit this film in BW, so I wonder if I should shoot in BW directly from the camera or shoot color and convert in editing.

Also, I want to shoot a part of the project in a way that I can slow down the action (semi slow-mo) and, the rest, I just want Full-HD quality to be edited in my Mac (iMovie or FCP).

Any input, help, explanations, links would be most appreciated.
Thanks, and excuse my ignorance in this subject.
Best,
E.

[Morgan_Moore]

I think AVCHD is higher quality - its easy to sort out with clipwrap mpegstreamclip or both

Typically you want to present in 25p .. thats 25 frames per second shown in your final film

You would record at 25p (25Progressive frames per second) - you want the shutter at 1/50th

Now if you record at 50p (1/100th shutter) - you have twice too many frames

So when you play those 50 frames back on a 25FPS timeline you get 50% slowmotion

Getting those 50 frames to play back at 25FPS will be a hoop in post production

Ideally you want to shoot the slomo bits at 50p and the rest at 25p

If you dont know what you want to be slo motion then shoot the project at 50p

Now if you play that 50 back at normal speed you will have to chuck every other frame out (another post hoop) - which will give a slightly stuttered look

its actaully pretty easy after a week on google..

BTW i = interlaced .. = avoid unless you are paid to deliver in an i format

S

[Morgan_Moore]

As for B+_W v colour .. I cant help

As for quality you want this highest MBs - that is more data per second

Now shooting 25 frames per second will give more data to each frame - so will be higher quality than 50FPS at the same data rate

S

[Photon-hunter]

Thanks for the kind reply. I thought that asking here would save me a week in Google..  ;-)

I hate to be a pain, but just a few things:

If I understand correctly, unless I am planning on using the images for slow-mo, there will be no benefit from shooting 50p? So I should stick to 25P then for the normal footage?

Also, when you say that the shutter speed should be 1/50 (1/100 for 50p), I guess that what you mean is that those should be the min. shutter speeds..?

Lastly, if I shoot 50p and import into a normal project (25p), the footage will automatically slow down 50%??

Thanks again for your input, most appreciated.

E.

[Morgan_Moore]

Thanks for the kind reply. I thought that asking here would save me a week in Google..  ;-)

Explaining the post according to your edit system will be beyond me.

If I understand correctly, unless I am planning on using the images for slow-mo, there will be no benefit from shooting 50p? So I should stick to 25P then for the normal footage?

Absolutely in fact you will be making a choise to merge the frames or throw some away - both affect the look for the worse

Also, when you say that the shutter speed should be 1/50 (1/100 for 50p), I guess that what you mean is that those should be the min. shutter speeds..?

No - the shutter speeds should be those numbers only ! - using a higher shutter will create sharp images that have no blur - and your footage will get a robitc juddery look that will give your viewers a headache

In bright situations you should control light using ND filter or a smaller aperture

(slower shutter is sometimes used for a dreamlike - more ill - end of Bourne look - faster shutter for fights - particularly saving prvate ryan) - the 'rule' is 1/50th for a 25p film

Lastly, if I shoot 50p and import into a normal project (25p), the footage will automatically slow down 50%??

No different software do different things - often just throwing half the frames away or blurring them together (nice)

In FCP you 'conform the 50p footage to 25p' using 'Ciname Tools app - its fast

[Photon-hunter]

Thanks for the detailed explanation. That was very helpful. Off to experiment now...

Best,

E.

[Morgan_Moore]

Some notes on your experiments.

Firslty your camera monitor (screen)  may not be representative of what you are recording - it maybe 50i all the time - you should watch on a computer

Your computer may also stutter and add issues if it is old!

Secondly

My first videos I often shot at 1000/th - and did not notice the stacatto look- now I would see it straight away - also wathcing footage at 25FPS looks lovely while 50FPS (at 50 timeline aka FPS)  footage makes me feel sick as it is woozy smooth

You develop an eye for it

S

[fredjeang]

E,

The reason why you have to shoot at those speeds are the ones Morgan mentionned.

I'd like to ad that it also has to do with the light frequency of a particular location.

The rule is that if you live in Europe, your speed will be 1/50 (wich coresponds to 50 Hz)
If you are in the States, it will be 1/60 (wich corresponds to 60 HZ).

If you shoot in Europe with 1/60 under artificial light (your house, the street...) you'll see a strong banding appear.
That's because your speed is not in alignement with the light frequency.

----------

AVCHD.

You have to think AVCHD like if it was a compressed JPEG. Let's say at 6 or 7 quality to simplify.
It's a "good" format for adquisition, but a really really bad format for editing.

The image recorded by your consummer camera is degradated quite a lot to be able to handle the amount of datas that motion involve.

You need to stop the degradation in post production, so you'd need to convert AVCHD to a suitable editing format.
AVCHD requires also in post a lot of calculations that tend to slowdown the editing.

Although many softwares can edit natively AVCHD, it's not recommended at all. So you need, to keep going with stills images, to save a Tiff from this Jpeg before you start to work on it.
The "tiff" would be your editing format. It could be Prores, DNxHD, HQX depending on the brand-system you're editing.

In the editing process, you'd prefer to work with low-res versions to speed-up the workflow and then on the color grading stage, you'd work with high quality versions to maintain intact the datas.
So you need to do an inquiery according to your system of how this can be done.

Then you do a master at the max quality possible.

From this master, you will create videos for the web, dvds, whatever your needs are.


Best luck.

[blgordon]

OK, I'm starting out by assuming that I'm an idiot and I need some help.  I don't understand at all why my NEX-7 acts like it does.  My understanding was that the camera used the settings that you had set up for still shots and that you could adjust aperture, shutter speed, etc. during a video shoot. 

I can change my camera to manual and get all the settings correct for 1/50 shutter speed with correct exposure, but as soon as I hit the video button it will jump to a much higher shutter speed and a wide-open aperture.  This happens in all modes as far as I can tell.  It is like it has a mind of its on regardless of what settings I want to use.  It acts like it is on "auto" even when I try to manage settings to get the correct shutter speed.  Once it starts shooting video I don't seem to be able to adjust anything but ISO. 

Can someone please tell me where I'm going wrong.  I'll be very grateful.

Bruce 

[blgordon]

If it helps.  I'm using a Sony Zeiss 16-80 A-mount with the Sony adapter.