hi to all and happy new year!
Oscar: cool project but I think that is very difficult to operate this way, too small tolerance and too small part for a diy project
take a look at what I'm planning to do ....with an adapter but a medium format one( the ground glass is big and can be used to preview the scene also)
Andrey:nice to see you back to the thread one question... is it possible with the new 5mp sensor binning 2x and have a true full size 1/2.5" 720p 60fps camera with the software we have?(I've tried the binning option with a link on the wiki maybe from polto or spectr the 353 and , like the camera link you have provided some ago "matteo.elphel.com" nothing happen)
many thanks
Matteo

While on the topic of viewfinders, here is a simple solution for a digital viewfinder for I think any camera really.

http://cgi.ebay.com/Playstation-2-PS...sid=p1638.m118

Tear it apart and remove the 2.5" LCD. Hopefully the LCD controller is not much bigger. Looks like it has an AV connection, and only $18.00.

I doubt this thing would be any good for anything other than framing and going through menu options but hell its cheap.

I would personally rather have an optical viewfinder, but this is just another option.

yes is cheap and with a small cheap spy camera that record ground glass picture can be useful for real time digital viewfinder

You could also just display the RTSP stream real time. This way you see exactly how the camera sees so its possible to see the exposure, white balance, and other data such as audio and histogram.

I used a 7" touch screen with the 333 before with an interface I wrote but I found it to be clumsy. Also, when working outside it helps to shield it from sunlight. But to use the touchscreen its necessary to remove the visor and the glare is back. IMHO there is no replacement for buttons and dials.

On the other hand, here is a picture of the viewfinder from I think SI-2K?
http://www.hdforindies.com/uploaded_...ain-782743.jpg

Once im done with the 353 front end, I will try implementing a touch screen interface again.

Daniel I also think of using the touchscreen to control the camera
some ago I have made this gui ...have you seen it? http://www.webalice.it/teo.poz/elphel_GUI2/
I've asked andrey the permission of use an elphel 333 from remote ftp to try to write an html page but it was harder than I though (I'm a civil engineer and I do not know software programming so much) maybe now that andrey is changing the elphel control to php is simple
I've seen that you have the skill to program software so if I can help you (on the graphic side) or with some idea... ask me :-)

Matteo, I'm not sure how you want to have the mirror reflect the image from that angle without a perspective distortion, or am I missing something.
I have all the parts ready, and I'm about to drill a hole in the side of the Elphel. It'll be pretty hard to get everything inside a tube and focussed right, but I think it's doable.

Daniel, a touch screen would be nice, but have you considered an usb numeric pad with assigned buttons?

Mateo, we have two civil engineers in our camera team:) The problem in user interface design is not coding, it's design. Usability and best use of the limited screen space.

Yes, in fact this was my temporary interface: http://www.applelinks.com/reviews/gifs/n50a.jpg

It worked great as a way to interact with the prototype, however it has its limitations. For example it is designed for use with the left hand.

For a while I worked on a simple input device using an AVR atmega128. It interfaces with the pc by a serial cable. It allowed me to add buttons and rotary encoders to control exposure, gamma, and some other settings. I was planning to use a small graphic lcd screen to output status and other data.

It may be even possible to plug such a device directly into the usb ports avaliable on the 353.

But I do not have the time or resources to continue that project.

I appreciate the offer.

I do remember seeing that picture before, at first glance I don't think it would be very difficult to do. If you would like to try again, you can use the example application I posted a while back. Its crude, but should get you going in the right direction.

The front end I am working on right now is pretty general, and not optimized for our needs. It wont be long before its complete and I will start on the filmmaking version.

Daniel: what did you mean with front end? maybe I have not understand it
for my interface have you tried to press the buttons!? I have developed it with the silicon imaging one in mind and starting with the idea of using a 2 frame html
the upper filled with the elphel camera main interface (so that you have all the control if you want) and the bottom with a flash type vector interface like I've done (with the cinema camera most used controls)...yes it have to be checked(in particular the gain and white balance and black setting) but I think it is useful the idea of choosing a parameter to change and the big single slide that appear :-)

Oscar: I think that the mirror is ok maybe it have to be checked the right angle ...try to put a picture 90° on your bathroom mirror and you'll see what I mean :-)

John: nice to hear that, 2civil engineer in a project like your! cool

Sorry, I have noticed that I use the words interface, front end, and application interchangeably. Really they all mean the same thing. A front end is the client side of an application. Its what a user will see and interact with. Generally the term front end is associated with a website.

I just tried the buttons, did not realize it was flash. Thats pretty neat, looks like you through it through. You could easily interface this with the 353 by making calls to PHP files.

http://www.kirupa.com/developer/acti..._php_mysql.htm

I know that I can interact with php with flash :-) but not already how so thanks for the links
I think I have also to understand how php really works before :-)
also I want to leave the flash web interface and make a simple html one so that it would be faster and "really open source"

I've made some progress with the viewfinder. Making everything adjustable so I can focus everything right will be difficult, but you can see it should work out.


It seems that I have to cut a little bit from the side of the body too.

Hi Daniel,

I've been thinking about that as well - and using this:
http://www.arduino.cc/

I bought the USB version and its very easy to program.
You download/install the compiler, write a few lines of code, hook up the USB connector and just click the flash button...and a few secs later your code is running on the ATmega board. I made a time lapse controller for my 20D in about an hour. :) - In the end though I decided it would be too much work and I think I'll be controlling my Elphel with a touch screen mobile phone running a web page from the Elphel via wifi from a USB dongle in the Elphel. That means no building stuff...keeping it a software solution. That in turn means whatever I end up doing is so much easier to share with others...and that makes it a lot more fun. //O.

Many thanks for your quick reply Andrey! I have a few more questions regarding the purchase but I'll put that in an email to you instead. Thanks!! //O.

I had some great tests with the viewfinder. Very clear and bright image. Perhaps it'll even be good enough to focus most shots. I still have to put everything together though and make a robust housing around the tubes.

Daniel, what are your thoughts about an internet tablet and the Elphel+HDD? (skipping a Laptop/PC) I'm thinking about a combination of the optical viewfinder and 'only' a 2x or 4x focus aid on the tablet screen. (not necessarily at full frame rate)

The two ways to get a preview image from the 353 is to either use the imgserv which will provide a jpeg image of the last captured frame, or to use the real time RTSP stream.

The problem with both options is that they are going to be very high resolution images of 2000x800 for example. At the moment the camera has no ability to downres images for preview. This is overkill for small devices such as cell phones with lcd screens of ~64x64, PDAs 240x320, or internet tablets of ~640x480 - 800x400.

Not only does it become a problem to display such an image, but its a lot of data to process and the CPU capabilities of such devices are limited. Furthermore, when displaying the full frame most of the data is processed and disregarded.

One of the options I was considering is to have a device server. Clients such as a PDA, cell phone, internet tablet, laptop, or desktop pc would connect to this server. The server would then format the RTSP stream from the camera optimized for the connected device.

For example, the DOP may be using an internet tablet or a similar device to get a preview of the picture. He would turn the device on, it would connect to the server over WIFI and he would get a properly formated image of 800x600 for example. If he wants to zoom in for focus aid or detail all he has to do is use the touch screen, and the server would send a new, or reformatted video feed/image. Using this device he can also configure the camera and more.

Or here is another example. The visual effects supervisor would like to get an idea of how well a scene matches a miniature shot, key out the bluescreen, do a basic comp, overlay videos/images, or would just like to simply give the director an idea of things are coming together. Using the handheld device connected to the server he can do this by the touchscreen, it would be computed server side, and receive the realtime or image preview.

The possibilities are endless.

The disadvantage of using such a server is that its going to make the system more complex. Additional power will be required, and it would make the camera package bigger. But you did ask about my thoughts :)



It is not imposable to just use a high resolution image from 353 directly on the hand held device. Devices with wifi abilities are best suited and would take minimum work to implement. You could possibly get the imgserv jpeg at ~6 FPS. The RTSP stream requires a lot of cpu resources. I believe the recommended was 3ghz for optimal performance, so I don't think thats a realistic option. It is also possible that requesting an imgserv image at a high rate will take a toll on the camera CPU and lower the recording frame rate.

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).

There is also another feature in the FPGA - not yet used (and needs some code to connect it to the output) - the amount of high-frequency components fro each of the 16x16 macroblock used in compression. This data can be used to provide info for the quality of focus if you average that data over selected region of the frame that you want to be in focus.

Andrey, ..this goes a bit above my head I guess. With data, do you mean in the form of a histogram or something?

What I meant with focus-aid, was only to show a the center of the image zoomed in 2x (like used in the ajax interface) and show that on the mobile device. The whole image would be unnecessary, because I would have it on the optical viewfinder. This is just an idea, because I understand that not everybody would be able to make the viewfinder... but than again, it would be a simple starting point.

Oscar,

It is more difficult to implement zoom window (w/o slowing down the main data) than to provide (per 16x16 tile) "focus quality" data, it is a by-product of the compression process, most of it is already implemented. Next time I'll get into FPGA code I can add output of such value over the specified window, we can display it as a bar in the UI.

Excellent!!! That would be VERY useful!

The resulting preview image would be perfect to ensure framing and make it very easy to control the camera using a wifi enabled device...like a cell phone with touch screen or an internet pad. Resulting in a very compact setup.

Even better! I was hoping for a feature like that but thought it was impossible. (due to CPU power) This would be an excellent way to check image sharpness.

Exciting news!

If possible - please implement this! It would make it totally possible to not just control but also frame/focus the camera with a wifi device.

I'd love to build a PHP web page where I can switch between a 1/8 or 1/16 sized image stream for framing...and be able to switch to a "focus quality" image to check for sharpness. Add to that a few controls for exposure/timing etc and we have a really cheap and compact camera controller. very cool

//O.

Oh wonderfull
 

great that would be heaven, will it be ready some days ??

Yes, sure. And focus quality in a specified window can be really soon.

What do you think - maybe this can be used to control the camera?
http://linuxdevices.com/news/NS2593777857.html

Viewfinder update...
 

The optical viewfinder is almost ready to be mounted on the Elphel. I will make it detachable, so I can always adjust things. And I'll probably make another one without the image inversion, so I can see the image from the 35mm adapter right way up.

Andrey, I'm very exited about implementing the focus quality. How can it be used in the control-panel (how should you read the focus quality)?

Oscar, that will just be a value that will be updated after each frame compressed. The focus will quality will be controlled fro specified window (in 16x16 pixels increments.

It has some resemblance of the JPEG image size (but that depends on all the frame, not just the center area). If you make a series of images with different focus settings (all the rest being the same) you can compare image size - the larger, the better is the focus.

cool the focus aid!
maybe ca be used the magnification area
1- position the magnification area in the point of the picture we want to focus
2- press the button focus aid
3- roteate the lens focus wheel to the right
4- press button focus aid
5- roteate the lens focus wheel to the left so that the software can calculate back the image size of the same (more or less) frame of the right rotation of the lens focus wheel and when the size of the frame is similar to the higher achieved a green indicator on the gui will tell you!

nice work oscar!

The viewfinder is about ready and working great. I haven't had time to put the sensor and main board back in the camera body, but that'll be ready tomorrow.

That would be awesome!
..might be tricky though as it doesent have wifi...? ..or maybe there's a way to hack it and use the USB port?

Maybe this one would be easier (although not linux based :( )
http://www.youtube.com/watch?v=lbdmM...eature=related
Its got opera, wifi and fast mpeg-2 playback.

Err - I just realized - archos is linux based and uses Qtopia... http://trolltech.com/products/qtopia.../qtopiadevices

Size & framerate...
 

Hi all,

I made a little framerate calculator...and thought you guys might find it useful too. You can enter the sensor size and full frame framerate and it will give you an approximation of the framerate att smaller image capture sizes.

Please let me know what you think.
If you need any other features - ask and I might put it in.

http://www.oddpixel.com/fps.html

//O.

or better :
a upper green arrow if the current frame is bigger than the previous 2 and a red down arrow beside the magnification 2x, 4x square if the current frame is smaller!
:-)

Hmm since it's just a value representing the sharpness of an area...I could write a little flash app that plots a little graph + does the arrow business on a continous basis.

It will not be of much help on a mobile device (maybe a small piece of php would work on those) but on a pc it should give pretty fast response!

I bought my 353 yesterday and I'll make that app as soon as it's arrived!! :)
(and post here of course)

cheers
//O.

That's great to see more people using the 353.
I have to put everything together again to use mine, but I have to get a new IR filter (I couldn't prevent it from braking when I cut out the piece for the viewfinder.) .(
In the meantime, I'm building a rod support for the Elphel and all other parts (adapter or lens, batteries and things like that.)


Elphel camera's come powered with 48v DC (unless you get a custom made version with 12v). What are the possibilities to use battery power?
Is there some affordable voltage doubler(or 4x when using 12v) available?

Ah! I didn't know I could get one custom made for 12v...hmm too bad.

The 48v issue should be possible to fix using a DC to DC converter...I'll have to read up on that been a long time since I did electronics.

We should probably ask Andrey...

48v converter
 

I don't know of any existent ones for the correct power, this is something I was planning to build - a simple 48VDC power injector that will take power from lower voltage source. It is even possible to make one that will take 5V power from 2 USB ports (1 is not enough)

Maybe we can keep in mind, lots of the batteries for 'consumer' DV camcorders are 7,2v. Is it also possible to convert that to 48v ?

That explains why I couldnt find any when browsing the net ;)

..is it still in the works - just postponed?

It would be real cool with a solution that doesen't involve modifying the camera itself, but instead something to hook between the camera network connector and a battery source.

If you decide to make that power injector Andrey, please put me on a pre-order list ;) hehe I'd love one thanks!!

Has anyone seen a good solution to hook up a Canon EF lens to C mount? The only one I found was birger.com's _very_ expensive solution...

I have a few C mount adapters & EOS extension tubes on order from Ebay, hoping to find a way to make one - with or without a groundglass.

Anyone tried this?

I saw the shots of your EOS experiments Andrey and that got me inspired! Btw I got the camera today!! Thanks for the excellent packaging and the extra body! Much appreciated! Doing my first tests now...

Odd,

Large (EOS) lens makes sense _only_ with the ground glass (or similar) adapter. If you just use EOS-to-C-mount adapter you will get quality worse than with the modern C/CS mount lenses, the sensor pixel is just 2.2 um x 2.2 um. The sensor size is about 5 time smaller than 35mm frame, so to get 5MPix resolution you need a 35mm lens capable of (5 x 5) x 5Mpix = 125MPix resolution

Ah! But of course...doh! Thanks for the clarification!
This is very much a learning process to me. :)

What I really want is to do a groundglass solution as I want the depth of field you get using the whole lens... - the EOS directly to C mount was more of a starting point.

Well you made it quite clear I better go for the groundglass solution right away. I better go read up on optics. ;)

Odd,

As the lens is removable, I would recommend to use a fancy one with a ground glass and just a C-mount type one as an alternative. To get the full resolution you need a really good one, but just to experiment with the camera operation, you can probably get 1/2" format C/CS-mount lens for the same price or cheaper than the adapter.