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Messages - Roman

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1
Hey,

Firstly please dont rip my head off if this is an idiotic idea, I dont know tooo much about audio but just had a random thought about audio and gain control. :)

People hate AGC, why?

Because it's automatically adjusting, and often not how you'd like. Once it's recorded, you've got no idea how loud it 'should' have been.

So first thing that comes to mind is turning the bloody thing off haha.

But I was thinking, what if there was a way to make the AGC aim to instantaneously normalise every volume to say 75% volume of what the mic can do... BUT the difference being that it datalogs the gain 'offset' required to get the audio to this level.

So something that would normally clip, records at 75% volume. Something that would normally be a pin dropping, records at 75% volume. So it would sound terrible, but the idea is that you post process this to use the 'offset' information to make the pin dropping super quiet again, and the clipped parts really loud again. But you never have to worry about clipping or signal:noise ratio being awful.

Here's a very poor visualisation of what I'm thinking.

First picture down is how you normally record... Volume goes up and down with recording.

Second picture down would be the "75% goal" AGC turned on.

And then third picture down would be the 75% goal AGC post processed into an 'HDR' audio file.




2
Share Your Photos / Re: Thread photos dual iso
« on: September 21, 2014, 09:42:51 PM »
Quote
with full respect but those examples are possible to shoot with just single iso..

And how are you able to judge that? From viewing an edited photo which has the contrast hugely reduced? lol.











3
General Help Q&A / Exposure adjustment finer than 1/3rd stop?
« on: September 14, 2014, 12:05:04 PM »
Hey,

So in the Canon menus you can set the exposure to adjust by either 1/2 or 1/3rd of a stop per click of the dial.

However! There are a few situations where having slightly finer control over the shutter speed would be beneficial.

Panning shots with motorsport, generally I start at about 1/100th of a second exposure time and then dial it up or down to suit distance from the vehicle, vehicle speed, etc.

However the jump from 100th to the next setting up or down can be quite significant, in terms of how much motion blur is in the picture. So sometimes I wish I had finer control.

Is there an ML option to somehow temporarily set the camera to increase/decrease exposure time in 1/10th stops or similar?

Or another option, is there a good way to take 3 shots at differening exposure lengths, say 1/80th, 1/100th, 1/120th while compensating exposure or aperture to keep the same brightness as the first shot? It would be handy for dialing in initially, which shutter speed suits best.

It's probably something that can be acheived already, but I'm not sure which combination of features would allow for it.

Apologies if this is a repeat or annoying question, I've used ML extensively over the last year or two but have not seen a combination which can acheive the above.
Thanks,

4
Share Your Photos / Re: Thread photos dual iso
« on: September 14, 2014, 11:54:51 AM »




5
Sheesh getting carried away a bit, Why even discuss mass production, when it's not even confirmed that it's possible to work yet?

6
General Chat / Re: My Rant on Canon's Lack of Innovation Lately
« on: June 13, 2013, 09:52:38 AM »
As has been said in other similar threads, most people impulse purchasing a DSLR are likely to end up with something Nikon, or something Canon with little or no tech knowledge about the differences.

So what are the motivations? With electronics there's the massive stigma that if you buy something old, you're an idiot and that's usually true.

If they go into the shop and see a 2 year old 650D or a 3 month old Nikon somethingsomething for the same money, they are going to buy what's newest on the assumption that it's better. Canon pushes out something 'new' each year in the ***D line for this reason, it would seem.

To be honest I think it's reaching a bit of a plateau in terms of what hardware features you can add to an entry level camera.

When you buy an entry level DSLR like a 700D, it's still bazillions better in terms of usability for first time shooters than it was 10 years ago.

In terms of the software innovation, which is effectively maximising the usability and effectiveness of the hardware with software - Magic Lantern has shown what each camera is easily capable of, if they chose not to ignore development in this manner.

Why in god's name no Canon DSLR has a built in intervalometer at the very least, so many years after a digital cameras have become the norm truly boggles my mind.

It seems Canon wants to treat it's DSLRs as though they are still film cameras, a mechanical item with the minimum software and firmware required to make it functional.

In saying this though it's sooooooo hard to change anything in a giant corporation, it's like trying to do a 3 point turn with an oil tanker.

If there's a "Dont fix what aint broke" mentality there, it going to change any time soon.

7
Raw Video / Re: Current raw video capabilities - All ML cameras
« on: June 11, 2013, 04:45:47 AM »
Updated 50D to new speed available - 70 to 73mb/s with the new build. Woot!

8
Raw Video / Re: Aliasing with RAW
« on: June 10, 2013, 10:28:19 AM »
With the 5D3, is it possible that they are sampling from the entire sensor, rather than skipping?

So for example to make one pixel, they take an average from an entire area rather than skipping sections and reading from only one part.

9
Raw Video / Re: Aliasing with RAW
« on: June 09, 2013, 09:54:08 AM »

Maybe, but isn't a crop mode made out of 1920x1080? (I mean picture with 1x magnification, resolution say 1792 x something)

Think of it as, because the sensor is downsampling in a way that means certain parts of the sensor are skipped,  there is a gap of a certain distance between parts of the sensor it records from.

A blurs the image an exact minimal amount, so the light that would have fell apon 'the gap' reaches the parts that are recording.

When you change how much of the sensor you are using, or using the full sensor at a different resolution, the size of the gap changes so the VAF filter will either now make your image blurry (if now less of a gap) or not work as well as intended (if more of a gap)

For what we're doing with raw, generally filming at higher resolutions with the full sensor, I would expect a vaf filter to remove aliasing at the cost of the image being blurrier than you'd like.

10
Also people are going "If we can shoot at xyz bits, we can use 10million x 8million resolution!"

Forgetting there's a certain sized resolution that's the maximum for each camera, some/most of which are already recording at the maximum available.

11
Infact this is exactly how I shoot computer monitors at work. Often you find a moire effect when the screen pitch matches that of the camera resolution (a form of extreme brick wall). The easiest way to solve this is to back off focus just a little bit. But sure you get a little contamination in the blacks/edges.

Or perhaps, (if lighting allows) stop down as far as you can go, to introduce diffraction... I think that's essentially the same as what the aliasing filter does.

12
I just came across this optical filter solution for moire. I'm intrigued:

http://recordingsofnature.wordpress.com/2012/12/04/cyl-filter-moire-and-aliasing-filter-for-hd-dslr-video/

Since there are lines skipped causing the aliasing, the problem is that some light reaches one pixel*, some light reaches the gap in the middle, then some light reaches the next pixel across.
So what an aliasing filter does is blur the light coming to the pixels, so the lost colour information that otherwise gets sent to the 'gap' is included.

 Which obviously reduces sharpness and contrast to some extent, but the idea of the aliasing filter is to reduce it by the exact minimum amount required for sensor size and how much line skipping it's doing so it's not noticably blurry...

Could you not acheive exactly the same thing, by shifting the lense focus by a tiny amount forward or backward from a 'perfect' focus and then sharpening the image afterwards?
I know that sounds pretty blasphemous to a photography crowd to intentionally misfocus, but maybe worth experimenting with.
Or just smear some butter on the front of your lense, hahaha.

* = I realise this isnt the correct terminology, not sure what the RGBG cluster type thing is called that recieves light on the sensor.

13
Raw Video / Re: Current raw video capabilities - All ML cameras
« on: June 06, 2013, 04:42:31 PM »
Does the indicated buffer change, depending on settings? As I get the 30+25 for 600D and that's it.

14
Raw Video / Re: Current raw video capabilities - All ML cameras
« on: June 06, 2013, 04:13:38 PM »
Ahh great stuff! Thanks.

600D buffer is 30+25

And 50D is 27+27+27+27+27+27   (27x6)

15
Raw Video / Re: Raw for the 7d
« on: June 06, 2013, 01:18:49 PM »
If you're concerned with aliasing then maybe give the 5D2 a test run before committing to buying one.

The available resolutions for the 50D in 16:9 aspect ratio are:

640x480     - 9.2mb/s
720x406     - 11.6mb/s
960x540     - 20.7mb/s
1280x720   - 36.9mb/s
1329x742   - 39.2mb/s
1440x810   - 46.7mb/s
1592x896   - 57.1mb/s   (max res unless using 5x zoom)
1600x900   - 57.6mb/s   (5x zoom only)
1720x960   - 66.0mb/s   (5x zoom only)
1880x1056 - 79.5mb/s   (5x zoom only)
1920x1056 - 81.2mb/s   (5x zoom only)
1992x1056 - 84.2mb/s   (max res for 5x zoom mode)

So it doesnt go as high as the 5D3, and doesnt have options like 60fps or whatever.

However given that it's 1/5th of the price or less, it depends on what that extra res, lack of aliasing etc is worth to you.

In saying all of this, it's still early days.
Unless you've got a burning desire to film in raw ASAP, it'd be wise to wait a little before committing $$$$$$ either way.

If money isnt much an issue, there's no disputing the 5D3 is king.

If you want to take a punt, then there's not much to lose with buying a 50D, even if as soon as you buy it the value drops in half, you've still lost less than the 'not brand new in the box anymore' depreciation of a new 5D3.

16
Raw Video / Re: Current raw video capabilities - All ML cameras
« on: June 06, 2013, 09:53:00 AM »
Yep I've updated so far with the numbers that Alex has provided - Is there any way I can find out buffer size etc for the cameras I own? As I could add 50D and 600D buffer sizes if so.

Most of the information left which needs filling in is ML related, so cant find it by looking at camera specs alone.


17
Raw Video / Re: Raw for the 7d
« on: June 06, 2013, 09:48:33 AM »
Wouldnt hold your breath for a 7D port at this stage...

As per usual the dual processors are the thorn in it's side when it comes to trying to make anything work with ML.

I think I remember reading in one of the threads that ML can be loaded onto one processor, but the raw stuff gets loaded onto the other, and the transfer speed between the two isnt good enough for a reasonable raw output.

(or along those lines)

It's a real pity the 60D has an SD card slot, it would be awesome if it could get CF speeds.

50D is alright but I really wish it had a flip out screen, and a nicer LCD resolution and a few other things I've become accustomed to with the 600D.

18
Raw Video / Re: Current raw video capabilities - All ML cameras
« on: June 06, 2013, 09:38:21 AM »
Thanks for the information - Yes I'll work on a better format that's updatable, later tonight.

However in the meantime if anyone's able to fill in any of the blanks as per above, appreciated.

Interesting to know about the 60D buffer - If only it had the CF slot.

Interesting about the 6D record rate too.

19
Raw Video / Re: Current raw video capabilities - All ML cameras
« on: June 06, 2013, 09:05:59 AM »
Okay thanks... Yep if people can specify exactly which resolution each camera is capable of in 16:9 @ 24fps then I'll update it to show the resolutions instead.

20
Raw Video / Current raw video capabilities - All ML cameras
« on: June 06, 2013, 08:54:13 AM »
Hey, I thought I would put together a quick comparison of where things are currently at with raw video for each camera type, and what the comparative upsides/downsides/limitations/strengths/etc of each are.

I've listed them top to bottom, of which to my understanding are currently the best options.

Here's a google docs version that you can edit:
https://docs.google.com/spreadsheet/ccc?key=0AgQ2MOkAZTFHdFFIcFp1d0R5TzVPTVJXOEVyUndteGc#gid=5

Note:  The image below is simply a screenshot of the chart, and may not contain updated accurate information.  Please visit the link above for the latest updated chart.



21
General Chat / Re: Build quality 600D
« on: June 05, 2013, 05:29:09 AM »
If they changed the 600D to what you want, it would be called a 60D and you wouldnt have bought it because something else was cheaper...

I've used my 600D on the end of a camera crane, and having something LIGHT makes a big difference to how much counterweight you need, makes the whole setup a lot less cumbersome.
 
No doubting that other things feel built a bit more solidly, but unless you're planning on throwing it down a set of stairs or something it's irrelevant in terms of reliability or longevity. Being light is one of the best things about the 600D, plastic ftw.

My 50D feels a lot more solidly built, but to what end? If I drop it, i'm more mindful that the extra weight is going to make it more likely to smash a lense. If I graze it it's still going to scrape the paint off... And not having a flip out screen is a pain.

If only the 60D had a CF card slot, it would be the best!

22
So just to be clear though, it hasnt been tested connected to an actual camera?

As that's half the battle by the sounds, making sure it's all a format etc that the camera is willing or capable of interacting with.

I wouldnt be getting carried away with getting 100s manufactured etc at this stage, if it's not been proven to work with a camera yet.

23
Depending on which picture option you select, the camera reserves more (or less) memory for that, which then becomes unavailable for raw recording.

So basically we're trying to select the option that hogs the least amount of memory, to give a bigger buffer available.

24
Feature Requests / Re: USB port mic on the 50D?
« on: June 04, 2013, 05:50:02 AM »
Just thinking about this some more, it seems obvious that the gopro would have some onboard sound hardware to interpret the signal etc. So a straight mic jack to USB plug wouldnt help if there's nowhere to send the analogue signal on the 50D.

However I'd imagine a regular USB mic has this onboard, and just uses the USB port to stream digital data and send/recieve requests like stop/start.

Something like this perhaps, with an adaptor to mini usb:

http://www.planetheadset.com/usb-microphone.php

Although it needs drivers installed to work with windows, so I've no idea how/if there would be any useful way to transfer data to/from a camera with it where things are a bit more limited.

Or alternatively, the Blue Yeti mic doesnt need any drivers installed to make it run... And I've got one of these already.

http://bluemic.com/yeti/

Might see what else I can find out about it.

25
Feature Requests / USB port mic on the 50D?
« on: June 03, 2013, 09:58:34 AM »
Hey, Just following somewhat on the train of thought from this topic:

http://www.magiclantern.fm/forum/index.php?topic=5915.msg45075;boardseen#new

It seems it's possible to transfer data to/from the camera via USB port in non ordinary ways.

Soooo, being a new found 50D owner, the natural conclusion...

The gopro camera has a cable that converts its mini USB port into a mic jack:

http://gopro.com/camera-accessories/3-5mm-mic-adapter

If using a battery powered 3.5mm mic, would it be possible to stream the info from it into the camera in a way that would be useful to gain audio/wav file record? Or even just a very basic audio data or some sort that could be comprehended in a way to make it good enough to synch an external recorder with.

I realise the 50D has the same digic processor as other cameras, but does this handle the audio component too, or just image processing? I think I recall someone saying something about seperate audio chips for various cameras.

Obviously the 50D has the most to gain from this possibility, but it could also be handy for other cameras having a second audio input/output if that helps with monitoring or whatever perhaps...

Yes, I have checked the "Dont ask for this/not possible" thread first... If this gets added, so be it :)

If it seems somewhat possible-ish I can find the pin outs for the gopro cable etc if need be.

Thanks.

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