Batteries voltage drop might be influenced by the current drawn from the cell at the time of measurement so I am afraid I do not have enough knowledge about this to build a safe battery pack.

But I think this monitoring device (Arduino or any other microcontroller) should be integrated in the battery pack. Otherwise it could result in the battery pack catching fire and destroying the camera or worse if the operator selected the wrong battery type and only the camera is monitoring the cells.



As far as I know the next camera CPU will be based on a very similar chip to the beagleboard: A Texas Instruments Davinci .... ARM CPU with video coprocessor.

Sebastian/Philippe,

Alexandre mailed me an interesting link to an Arduino alternative (and possibly better):
Teensy USB Development Board (teensy++)
What do you think? Anyone here has experience with this?
Oscar

Teensy looks great:
-) smaller than Arduino
-) more IO pins than Arduino, better specs
-) Development Environment seems to be compatible with Arduino
-) cheaper than Arduino

Only con I see so far:
-) Cable on Mini USB jack detaches easier than the normal sized USB jack in the field


Small update on the Dictator:
-) I totally forgot 2 things: the Rec button and the on/off switch :)


Since the Teensy++ has 46 IO pins we could easily add more pushbuttons (they are very cheap as well). What other settings would you like to be able to change with a pushbutton?

Here are some images of the available pushbuttons of the competitors:
http://www.dvuser.co.uk/images/img/n...-back-1920.jpg
http://www.vanbrandwijk.eu/uploads/image/ex3.jpg
http://www.panavision.co.nz/images/_large/aghvx200.jpg
http://www.digitalcamcordernews.com/...-hvr-s270u.jpg
http://www.hd-tv.nl/images/news/282.jpg

Looks good. Would this be possible to build in some kind of project box (with pre-made holes for knobs, LCD and buttons)? This way you could make a DIY guide for people who want to make it themselves and we don;t need custom manufacturing. I'm searching, but didn't find anything yet.

EDIT:

Maybe we could look for things like this:
Product Photos
Product Photos

Here is a cheap battery+charger I came across:
Laptop Nimh Universal External Battery, 12V 3500mAh + Wall Charger for IBM Sony NEC etc (P1000) - CH-1540-UNC03

Very interesting link!
 

I found a very interesting company that makes custom designed front panels (with there own software) . So a simple project box and a custom front panel would make a perfect Dictator enclosure.
I did a quick test with the software (using Sebastian's design as reference): A black aluminum panel (100x60mm) would be $ 18.- (10% discount at 10 items, 20% for 20 etc.)

Home*- Front Panel Express, LLC > Front Panel Service for North America

Very cool!

For prototyping any CNC mill should be able to do the job. But 18$ looks like a very good offer (does it even incude printing/engraving on the panel) and the company you found could in general be very interesting for our needs.

very cool oscar the link
here is a link to an arm for the tablet or lcd
that is strong and good looking

Holding System By NOGA

pdf sheet

Very useful the dictator concept
I've not understand what does the two rotary encoders
or better, does we need 2 rotary and a 2axis joystic?

maybe with the next revision of the elphel we have some more processor power to do video output so a simple LCD + dictator could do the job

Interesting product Matteo.

Does anyone know if a 6mm c-mount intended for 2/3" sensors has the same FOV as a 6mm c-mount lens intended for a 1/3" sensor? I mean: is it calculated for c-mount in general or for the sensor size?
Or is it just that you can't fill the whole 2/3" sensor area with a lens that was intended for a 1/3" sensor?
If not, what is the multiplier factor?

Oscar,

I read (forgot where) that it depends on the lens. Some have enough coverage for bigger sensors, some don't... It seems you have to test. Well, if you order online, it's another problem :-/

exaclty as a aps-c for actual reflex and a 35mm lens
as you said Oscar "you can't fill the whole 2/3" sensor area with a lens that was intended for a 1/3" sensor"
take care that some industrial lens are for example 3mega pixel capable but only for the sensor size they are designed for
a 3mpix camera for 2/3" can resolve about 1mpix on a 1/3" sensor

for size and some info about thake that link
Optical Characteristics of Video Lenses

and look at the tamron catalog for c-mount lens
Tamron CCTV and Photographic Lenses for Factory Automation, Machine Vision & Security
they have monofocal lens that have a minimum object distance of about 10cm
(like fujinon one but fuji is more expansive) so we can use adapter without achromat lens to reduce that distance

CNC milled/drilled front panel
 

If you want avoid intl. shipping, the headquater of Home*- www.schaeffer-ag.de - Frontplatte, Front Panel, Face Avant, Frontplatten Designer are in Berlin/Germany, offering the same service in EUR. And they also offer case kits with alu profiles and plates.

PIXEL PARTNER (R)
Thomas Kumlehn

Ready-made part list
 

Hi everyone.

I'm working on the rods support design again. How about collecting all
ideas for ready-made (existing) parts?
By this I mean: hand-grips, rods, microphone holders, knobs, electric
wiring solutions etc..
There should be numerous cheap parts around to make almost the whole
Rods support and mount all accessories.

Lets first bring together ideas and put it in an open google-document
later on.

So far I noted:
hand-grip:
AF10926 Barska Accu-Grip Handheld Binocular Support System, Pistol Grip with 1/4-20 Male Thread, Black Plastic.
universal holding arm(Matteo):
Holding System By NOGA
Ready to use battery system(Polto):
DigiPower

The first thing I'm looking for for the design is a universal laptop
or monitor holder. One that should be adjustable to hold any small
type of laptop/tabletPC/7"monitor. Something that fits this design
Image:Perspective2.jpg - ElphelWiki .. so
it doesn't need to have an arm.

All ideas are welcome!

Slightly updated Dictator concept.

The whole interface can be locked with a sliding switch and 2 sliding switches can lock each rotary encoder individually.



About the parts:

How does this NOGA arm system compare to a traditional magic arm? Price, weight, ease of use, ....

The Handgrip looks good and cheap. For later revisions we might think about our own design with some buttons to start/stop recording for example.

About NOGA arm:

HoldIT - DG Holder 3/8" - 1/4" +Nut. - DG11043

I've contacted an italian distributor (by phone) and they told me that
the price for the DG11043 is 80euro (support for 4kg)
and for MG11043 is 95 euro (support for 8kg)

but these are for cinematography purpose
I think that the same result could be achieved with the arms in the first noga link I've post
that, as distributoris said, are cheaper.

We should also be looking for something like this: RAM-234-6 Tough Tray II because the NOGA arm can not mount a laptop or tablet PC.
This is the only laptop "clamp" I could find. Does anyone know of other/cheaper ones?

UPDATE: Prototype and website
 

Time to show the first -rough- prototype of the APERTUS based on this design
This is of course based on my own DIY microwax 35mm adapter, but it should be pretty universal. Besides 35mm adapters, it can also be used for bigger c-mount TV lenses if needed. I'll post some tests with different setups in the future.

There is still some work to do on this prototype before I can test it.

Another thing we forgot to announce here is the new APERTUS website:
Home page | Apertus Open Source Cinema
It's in the early stages, undergoing a theme change, so it's a bit off here and there. Thanks to Philippe Jadin for setting this thing up!

I thought my current 35mm wax adapter looks too bulky.
So I decided to adapt a macro bellow for 35mm cameras for the wax adapter. The focus mechanism (although not very subtle) can be used as follow focus.
I also want to try to integrate a sort of relay lens into the adapter.
I've discussed this with Andrey Filippov, he suggested: "A trick we did (that was to transfer 1:1) - take 2 identical lenses and put them face-to-face.
In your case you need ~1:5 transfer, so you need the second lens 5x the focal length.
I.e C-mount with f=8mm and a 35-mm with f=40 mm"

I've done a quick test and it seems to be working! Anyone got more input on this?

hi oscar cool work
seem exaclty as the render
one question about your test how does it manage the light loss and the spherical aberration
did you need also a condenser/aspherical-condenser between the 5x lens reversed and the GG?

Matteo, the wax screen is sandwiched between two condensers.
The light loss on my waxscreen is about 1 stop I guess but it depends a lot on the lenses (also the c-mount) I have to test this (and the spherical aberration) further.

In the future I want to test different 35mm adapters on the APERTUS.

hey what do you guys think of this: if the camara gets more light by pixel binning, then why not make two processes, first the normal image ("un-binned") you get a "low luminosity" image and save it, then the pixel-binning processed image "high luminosity", and compare the burned parts of the "high" image to the "low"

obiously both "low" and "high" should be extracted form the same raw frame (to make sure that both images come form the same original stream and have the same exact features minus the exposure diference)

wouldn't this gave more dynamic range to the final image? maybe the camera can't do this in a workable framewrate, but this could be a begginning, no? what do you think?


------------------

i have to admit, i love Apertus! how is wobble effect in the elphel?

@Biel
I think that something is in development
JP4 HDR - ElphelWiki

and also in hardware:
info from the aptina data sheet
Pixel dynamic range 70.1dB (full resolution),
76dB (2 x 2 binning)

Matteo i've seen this, but my idea isn't exactly this, the idea is to use the same info coming form the ccd before any pixel binning is done, the idea is to use the original image and the "pixel-binned" one and merge them to get a little nit more of dynamic range (only if by pixel-binning on gets more light, otherwise this porcess would be futile)

anyway if this porcess is not futile and also the Process Matteo said one could get an awesome dynamic range gain from the same camera, what do you guys think?

Interesting idea.

In theory it should be possible to gather higher dynamic range data with this.

But I see some potential trouble:

-) As you mentioned this will not be possible at full fps. Changing binning mode will require at least one if not multiple frames to execute.

-) Binning is a CMOS on-chip feature rather than a post-processing step so it is not possible to get the data "before" it happens. You can only take 2 shots one after the other, one with binning on (2x2 for example) and one without binning.

Binning does not only mean more dynamic range but also more light sensitivity. 4 pixels are brighter than one.

Even if it is not possible to do it at a usable FPS it would be interesting to do it as a proof of concept no?so when chips get more fast it will be prooven no?

is there a way to get the info from the chip in order to pixel-bin, but do it as a post process? like getting the image from a non-pixel-binned process and pixel-bin it when its not al already done, i mean do a porcess in post (than means after the chip has got the image (not "post-pro")) from a non-pixel-binned iimage:


lens - chip - stream data - pixel-binning - stream data + pixel-binning - raw enconding - file

here pixel-binning and the operation joining the two diferent streams would be a postprocess before the raw encoding of the file
instead of:

lens - chip - pixel-binning - stream data - raw encoding - file

or does pixel.binning actually means that the chip uses 16 photosites instead of the normal 4 for a final pixel? if that is pixel binning then maybe its not possible...

Exactly that is binning!

Instead of a single photosite the sensor can add up the charges of blocks of 2x2, 3x3, 4x4, 5x5, etc. photosites.

Anything regarding resolution reduction after the sensor is "resizing".

well then...
damit i loved that idea because it's simplicty! :(

Hi Biel,

I don't know if it's really impossible, but I guess it's not simple. Anyway, we where just talking about the Elphel's FPGA features, here's part of the discussion:

Over a year ago Andrey wrote: "For the viewfinder mode it will be
rather easy to make FPGA to provide 1/8 (or even 1/16) resolution (so
1/64 or 1/256 number of pixels) of uncompressed data in parallel to
the video, virtually without using additional resources (so not
slowing down the recording)."

"Anyone know if this still true?
....is this also one of the goals for the Elphel Vision interface?
... the 7" tablet PC has a lot of trouble with the high resolution stream. I don't think it'll ever show real time HD video.
A horrible blocky image is even preferred if it's real time above a beautiful HD image that is one second behind.
Especially if we have the focus aid.

(Oscar)

"...apparently this has never been implemented. But as I also recently
learned is the FPGA only filled 40%. That means there are plenty of
resources. If we find someone who is a skilled verilog developer it
might be possible to have the feature added.
....After all I also think its the only way to enable us using something
like the beagleboard as viewfinder."
(Sebastian)

Regards,

Oscar

i don't get it Oscar, what are you triying to say? does resizing have the same benefit of the pixel-binning? can luminosity (ore even chroma component) of 16 pixels combine and form a brighter (and maybe a more color-correct) 4 pixels?

and then combine that image with another resized (16 to 4 without the post-pixelbinning process)

and get a similar latitude as the process i wanted to do?

Very first alpha version of ElphelVision Java Applet is ready!

This is still in a very rough and early condition but it should work and maybe already be kinda useful.

It lets you view the video live stream, shows camera infos and record video files to camera internal HDD.

Detailed instructions on how to setup and use are included as README.txt
Currently only works under windows.
Final version should be platform independent as long as your platform can run Java and has an mplayer build.


Please let me know if it worked, how it worked, etc.

http://community.elphel.com/Apertus/...on_Alpha01.zip

hey Sebastian, that's good news! I'll try to test it right now, or first ting tomorrow (just came back from a trip to Holland) No problem it's only Windows, I just installed Windows 7 (test version) on the tablet PC. I guess using Windows for the end user makes it a lot more attractive for lots of people.

Sorry if I'm confusing things :-) I'm not a programmer, but I was trying to follow your idea: I thought it might be relevant to mention that we were talking about two 'streams' parallel.

ah, ok, now i get it, but this "uncompressed stream" means this, uncompressed stream ,not before the raw encoding but after the raw encoding, i was referring to the stream out of the chip, that means before creating any raw file, but as Sabastian said, you can't have both binned and unbined images out of the chip, you only can have one (or is it possible?)


sebastian---
i'm strating to program in java and i would love to contribute to the program, i've done a little aplication that converts a given number of frames at a given Fps to a SMPTE timecode(at the moment it's is only itegers, so i don't know how to do 29.97, but I'll learn)

are you interested in it?

Open source software development is all about collaboration and working together. So this is a good idea in any case.

My suggestion for the next lecture: Read about the float datatype :)

no, no i know it :) but what i don't wanna start getting is float frame numbers, so i need the computer to understand that you can't have 3.5 frames, there is 4 frames or 3 not 3.5, you know, all that kind of things, anyway sorry to go offtopic, i'll send you the program and you decide

i'm triying to do a java libarary of SMPTE workarounds like let the user enter a String and make the computer understant it as a SMPTE code, or give a exception signal back to the user if what he has written is not a SMPTE timecode... all that kind of things

OK, I've uploaded the files to the camera. Anyway, it a great start! It seems to be working fine. I had to restart firefox a couple of times till I found out how to use it, it seems to hang when you do something wrong.
I noticed that it only works when camvc is also running and updating the image. So camvc is showing a frame a second or something, but Elphel Vision is streaming the video at full FPS. The stream (on my fast laptop) is not real time, I think 0.5 sec behind.
So far my findings, I'll test it on the netbook tomorrow.
Again, great job so far!

Now that we have a dedicated forum for Apertus, it's time to close this particular
thread. Please continue any further discussion by creating new threads. Thanks all,