Show posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Show posts Menu

Messages - dpjpandone

Camera-specific Development / Re: Canon 50D
May 22, 2014, 06:04:11 PM
Here is a cbetter picture of the blotches and lines
Camera-specific Development / Re: Canon 50D
May 22, 2014, 05:55:43 PM
Here is a screengrab to show what I am describing:

This is shot at f2.0 1250 ISO (1600 pulled down to 1250 with ML-3)
shutter speed is 50, FPS is 23.97

Now this is a scene lit only by a 100w table lamp, but at these settings I can get a great exposure with reasonable level of noise on 600D, is there something wrong with my 50D's sensor? Or is this normal? It looks fine with adequate light, but in low light the noise is unbearable....

BTW, does RAW Video benefit from the iso's pulled down?

Am I just not used to seeing this noise because H.265 clips the shadows and applied a picture profile? Or is this an unusual amount of noise? I really don't know what to expect because I have no experience with this sensor... I see small black blotches that come and go and a strange criss-cross pattern of vertical and horizontal banding. It looks like a defective sensor to me..

General Help Q&A / Re: Wireless Audio Sync Module
May 22, 2014, 04:13:38 PM
Optocoupler? This is a component used to isolate two systems with two power supplies. I think you mean a photoresistor....

anyways, this would be a very poor solution, it would be unreliable. I would not trust it to trigger my audio, it the tape falls off your audio will get triggered by ambient light in the room. If I have to use LED, I will remove the LED and wire directly to the leads.

I'm still hoping to get it through the shutter port so that the transmitter can stay in the battery grip.

USB is somewhat crippled during RAW capture...

This is not to discount your idea, I appreciate feedback. Please keep it coming.

General Help Q&A / Re: Wireless Audio Sync Module
May 22, 2014, 04:14:28 AM
I measured the half-shutter pin with a voltmeter. When I press the halfshutter button on the camera, the halfshutter pin goes from 3.3v to 0v, I was hoping that I would find the same behavior when starting the camera from the "set" button, with sticky-halfshutter enabled I expected to read 0v from halfshutter pin until recording stops and then back up to 3.3v, but it seems that the software is not changing the logic state at the shutter port, only the mechanical switch on the camera's shutter button does this.

So A1ex, can you think of a way to change this behavior, do you think it is possible to pull the physical pin low in software? I don't like the idea of using an LED because the camera will have to be modified. I think most people would be more comfortable hacking into a $30.00 battery grip or remote shutter cable.

if this is not possible, is there a way to ensure a constant delay between when the halfshutter button is pressed, and when the camera starts recording?

General Help Q&A / Re: Wireless Audio Sync Module
May 21, 2014, 07:25:19 PM
I was hoping someone could tell me if this is possible? To set the half-shutter pin to a logic state (LOW) from software? If not, is there some other place I could just send a logic signal out of the camera? preferably not audio since 50D has none...
Quote from: sync24fps on April 15, 2014, 04:10:37 AM
The 50D is a better performer in low light for RAW capture than the 5D MKii and 7D!  At only 25% less resolution than the 5D mkii, its surly worth the price to pick one up. 

I am experiencing iso noise that is sooooo bad I'm afaid to shoot anything higher than 320. Can someone tell me is everyone just removing it in post? Or am I the only one who feels this way? I have used the t3i for the last two years, and I'm comfortable shooting all the way up to 1250, but 400 on the 50D looks worse than 1600 on the 600D. (to me) am I spoiled? Should I just treat it like a slow film stock and avoid high iso's or is there post magic that makes the higher iso's acceptable?
General Help Q&A / Re: Wireless Audio Sync Module
May 18, 2014, 05:14:06 PM
OK! I started writing a blog post to show you guys how to modify the battery grip, complete with pics and arduino code:

I am so pleased with the result! I was thinking of a way to mount this for a while, initially I had the arduino in a small project box that I attached to the hotshoe, but this is so much cleaner, no wires attached to the shutterport, and arduino shares the camera's battery for power. It can be turned on and off with the battery grip switch if you follow my instructions for wiring!

So if anyone can help with the module I described earlier, I will happily send you a pre-modified battery grip for your camera so you can play with it!
General Help Q&A / Wireless Audio Sync Module
May 18, 2014, 04:57:36 AM
Hey guys,

I have been experimenting with arduino mini with built in wireless radio like this:

one of the projects that has been very useful is I made a wireless sync system for all our dslr's and ext. audio. Using the "start record from shutter half press" feature of ML, I press a button on my base unit, and all cameras + audio start simultaneously. There is a few frames of variance (delay) because the delay between triggering through shutter port and recording actually starting varies from take to take. What I would like to inspire is  a module that triggers shutter half-press when the first frame actually starts recording, so that a camera can be used as master and there will be no variance between the master camera and ext sound. I am currently working on encasing the wireless modules inside of one of the battery slots in a battery grip so the whole thing is self-contained and the arduino can draw power from the camera battery or ac adapter.

The biggest advantage would be for 50D users (I am one), since there is no reference sound for plural eyes, it is of the utmost importance that there is a predictable amount of delay (that I can compensate for on my dr-40 audio) This will also be useful for the other models. I plan to have some pcb's fabbed that fit inside of battery grip since I need several, I could offer a kit if anyone else is interested in building the wireless sync system I am using.

So the way it should work is like this: you press "set" to start recording, once the first frame actually starts recording, the camera pulls the halfshutter pin low, the arduino sees this event through digitalRead, and then transmits to the arduino connected to ext sound device, which triggers sound recording. This way, there is a predictable amount of delay (we can calc time for transmission and program this as pre-delay value on our ext sound recorder)

You can put as many transceivers on the network as you like, to trigger all the other cameras via shutter. The range of the RFM-69HW is well over 300meters. It's such a nice system to use for live events where you are using a lot of static cameras. I am also working on wireless video rx/tx (sadly only composite) but I'm testing some low cost transmitters because Ideally I'd like to have a wireless video feed from each camera and trigger each camera from buttons on a small 7" monitor. So I can enjoy most of the concert, and have visual feedback of battery and memory status so I know when to make my rounds.

What do you guys think? Can you help me get as far as a module that pulls halfshutter pin low on record? I already have everything after that working. I plan on getting into development on ML too, but I thought this would be really easy to implement for someone who is already experienced, and I could focus my efforts on the external hardware for now.
Camera-specific Development / Re: Canon 50D
May 16, 2014, 02:25:12 AM
Can someone tell me what to expect using an external monitor with 50D when shooting h264? what about RAW? am I limited to 480P like on t2i? Does the screen blank for a second when you hit record? what external monitor do you recommend for 50D?
Hey ML forum,

I have been a fan of your work for so long. I have always been very satisfied with the stable build on my 550D and 600D. I recently started experimenting with RAW on the nightly builds,  which has led to me getting a 50D. I have some experience coding on arduino. You can read about my wireless follow focus and other video related projects here:

So I would like to try to contribute to the development efforts. My 50D will arrive tomorrow, I'll be setting up the toolchain and reading a lot today. Thanks for letting me be a part of this community!