NBTV Camera Question

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Postby Harry Dalek » Fri Apr 27, 2012 7:44 pm

DrZarkov wrote:Looks a bit like him:
:D


Hi Dr Z yes it does a bit but mine has one wonky eye till i do the electronics for the LDR one :wink:

Metallica Man X wrote:That thing looks freaken beast!

Hopefully it'll work without a hitch :)



Oh its a beast alright a little beast ...yes i really hope it works ...

i just finished the monitor part and am testing NBTV , looks ok ,least i have a way now of syncing the light sensor video..

I am using the 3 transistor led driver from newsletter 27 ,4 and works fine .

I think i will still have to do a little auto amp between the two ,i will look into that tonight ...

It will be interesting once finish enough to work and am getting close now .

I will post some more pictures soon .
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Postby Harry Dalek » Sat Apr 28, 2012 9:58 pm

Today i was testing the monitor part ,the magnifying glass to blow up the image in this case is not so good well so far ,i am finding due to the hole size is far to large for the picture size its not a good idea to magnify the problem ..its far better to see it real size ...

Haven't taken any great shots yet as its hit and miss what you get at this size ,and doesn't look good blowing the image up.

I might mask my light box off a bit its far to large for a little image like this .

Oh and i swapped to a Black cd its better for what i am doing.

I have made 2 other Nipkows today tried this time to do tiny and the smaller hole one is not viewable with the one watt luxeon.

But i will try them out for the camera part,i don't think i will get great pictures from the monitor at ths size apart from its, least i hope it will come in useful in getting the disk camera to the right speed.
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The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Postby gary » Sat Apr 28, 2012 10:24 pm

Hi Harry, I am not entirely sure what you are reporting here but just a few thoughts:

1) Aperture size - well yes but you knew to begin with that those holes are too large (for the camera as well don't forget) - you need the sizes I have listed previously.

2) I would have thought a 1 watt luxeon should be more than enough light - I had nowhere near that much light and I got acceptable pictures - sure, pictures this small will be dimmer than a larger one - but they are still very much viewable especially in low light conditions.

3) I can't quite work out why you keep saying having the monitor will help you with the camera speed - won't the input to the monitor circuitry be from the camera? That won't help with the speed as they are always in synch regardless of the speed of the disk. If it's NOT from the camera and you are going to pump an external video source to it to bring it up to speed then you don't need the additional 16 apertures and you don't need synch holes just use a printed encoder pasted on the disk encoder.
This may allow the camera apertures to come out to the edge of the disk if you had synch holes there - the closer to the edge of the disk the larger the apertures can be.

4) Disks this size are problematical, mostly in terms of accuracy, but you can do it - having said that, for your first camera, a whopping BIG disk would have been a better choice ;-)
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Postby Harry Dalek » Sun Apr 29, 2012 11:29 am

gary wrote:Hi Harry, I am not entirely sure what you are reporting here but just a few thoughts:

Sorry gary i was hooking up the little monitor part to my pc to test it ...i have a simpler circuit running it just really have brightness control only so some nbtv test cards work others not ,i just get a dark screen but can see its there but to dark to see any thing perhaps not enough amplification to drive that luxeon on some ...but anyway i also found the ones i can see don't look great trying to look at it larger,like i can see the baird test card but when i try to look at it larger detail is lost.
I am going to hook it up to one of my other monitors circuit that i know works ok to see.


1) Aperture size - well yes but you knew to begin with that those holes are too large (for the camera as well don't forget) - you need the sizes I have listed previously.

Yes thats why i tried now making tiny hole nipkow...but hole size i can only work this out by eye and my needle drill ,unless i can find one of those drill bits you had to do this more to a standard procedure .
I more than likely need to direct that light to a smaller area

2) I would have thought a 1 watt luxeon should be more than enough light - I had nowhere near that much light and I got acceptable pictures - sure, pictures this small will be dimmer than a larger one - but they are still very much viewable especially in low light conditions.

Its the luxeon circuit i am using i think and alsol i have swapped Laptops my other one must have a better sound output than this one as i noticed a large drop to this one...kids knocked it off my table bad part was the sound plug was in it at the time and its broken plug inside and i nad no sound out put till i get brave enough to pull it to bits to look.
But looks like i still have a bit of work on this side of it .

3) I can't quite work out why you keep saying having the monitor will help you with the camera speed - won't the input to the monitor circuitry be from the camera?

I mean it will help me get the camera to the right speed to output to record...i have not seen a monitor camera together like this run from start up to 750rpm so i am not sure what it will look like apart from it would be no syncing problems at the correct speed...i just wanted the monitor to see this part and adjust and stop any roll best i can to out put the camera signal.


That won't help with the speed as they are always in synch regardless of the speed of the disk.


This i was expecting but i think i am right in saying you will get a locked image half or correct or double the 750rpm speed ? again i am not sure what it looks like between these speeds same as looking at any nbtv signal till you get a picture at the correct speed gary ?

If it's NOT from the camera and you are going to pump an external video source to it to bring it up to speed then you don't need the additional 16 apertures and you don't need synch holes just use a printed encoder pasted on the disk encoder.

I haven't got around to this part yet i recall you saying just paste the print out on the disk for the sync signal outputting part...i have seen that disk on the forum post a while back ,i have it on my other laptop that had the nasty accident .

This may allow the camera apertures to come out to the edge of the disk if you had synch holes there - the closer to the edge of the disk the larger the apertures can be.

The two other nipkows are larger closer to the edge i suppose you use as much space as you got for size with these things.


4) Disks this size are problematical, mostly in terms of accuracy, but you can do it - having said that, for your first camera, a whopping BIG disk would have been a better choice ;-)


I do make life hard for my self ! oh one thing i was wondering about the picture you posted was the thickness of you Nipkow looks pretty thick is it a lens disk Gary?
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Postby gary » Sun Apr 29, 2012 12:07 pm

Yes it's a bead disk so the thickness doesn't come in to it (within reason) - that, of course is not the case with a normal disk - on the camera used for your first example I used a club Darvic disk - and even this type is really too thick for a camera - ideally some very thin aluminium or stainless steel should be used.

BTW and I hesitate to say this because I know how easily you get distracted ;-), but it would be quite easy to turn your cd disk into a bead disk which would mean aperture size would be no longer an issue for you.
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Postby Harry Dalek » Sun Apr 29, 2012 2:55 pm

gary wrote:Yes it's a bead disk so the thickness doesn't come in to it (within reason) - that, of course is not the case with a normal disk - on the camera used for your first example I used a club Darvic disk - and even this type is really too thick for a camera - ideally some very thin aluminium or stainless steel should be used.

BTW and I hesitate to say this because I know how easily you get distracted ;-), but it would be quite easy to turn your cd disk into a bead disk which would mean aperture size would be no longer an issue for you.



I was thinking it might be that ,no Gary i will not go off track yet making a bead disk ,i wouldn't mind trying it some day .

I still have in mind once i see it working to improve it cutting out most of the cd and glueing a thin disk perhaps paper as i used in the drum monitor ,or tin foil ,you'd have the round outer edge of the cd or dvd and 3 or 4 thin arms holding it to the center and glue the thin disk to this skeleton dvd cd might work or perhaps it might be worth a bead disk try then too least i would have a test bed to test these disks out on .

Had in mind to see if it could project nbtv its a luxeon i am useing as a light but i think it has some electronics to it as different off then on signals to it cause it to flash or dim brighten ..so might filter out the video.

I was reading in one of the news letters a while back someone made a pin hole camera doing away with the lens ,and some one else has made a cd camera read a mention of it so that must be possible even if i fall flat on my face but i will give it a go.
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Postby Harry Dalek » Tue May 01, 2012 12:09 am

Today been working on the monitor redesign the light box is now just above the projection light and directing the light to a smaller area and i can now use the tiniest hole nipkow i have made so far the lights don't seem to interfere with each other .

Its scanning the right way now so that helps ! just a few lines difference to the projection light one so thats not to bad the other way was bothering me.

I got some test cards up today but mainly high contrast ones checker board NBTV signs stuff like that stuff every thing else looks washed out or out line looking .

I am also just using a LM317 to control the motor but even on bottom setting its running this tiny motor to fast to control ,i think i am going to swap to a PWM circuit i know i can run it better then and take some pictures of the monitor ,its not to bad now via the Magnifying glass.
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New monitor design
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Postby Harry Dalek » Wed May 02, 2012 12:54 am

My PWM motor drive circuit worked so i tried to take some pictures tonight but have run out of time this is the best one that came out and thats not great of the NBTV letters .

This is via a lens the image is only a few tiny millimeters ,i can see from playing around tonight i need more light out of this luxeon some thing is up i will adjust some of the resistor values see how that go's...
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Picture 31970.jpg
My first very bad shot of nbtv test card
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The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Postby gary » Wed May 02, 2012 1:21 am

Harry, you seem to have your signal inverted.
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Postby Harry Dalek » Wed May 02, 2012 7:52 am

gary wrote:Harry, you seem to have your signal inverted.


Yes its just a one transistor circuit i need to Just make the club circuit with the opamps thats always worked well for me ,i noticed in Alberts post there a version with a transistor at the front end not seen that one before /
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Postby gary » Wed May 02, 2012 9:49 am

What is the source of your signal? (e.g. PC, CD, etc)
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Postby Harry Dalek » Wed May 02, 2012 5:28 pm

gary wrote:What is the source of your signal? (e.g. PC, CD, etc)


Gary i always use pc wav files via VLC player .
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Postby gary » Wed May 02, 2012 5:35 pm

Then may I suggest you either:

a) Invert the signal via an audio editor like Audacity, or

b) Use TBP which allows you to invert the signal in real time (under settings) and you can see what the picture should look like at the same time.
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Postby Harry Dalek » Thu May 03, 2012 10:54 am

gary wrote:Then may I suggest you either:

a) Invert the signal via an audio editor like Audacity, or

b) Use TBP which allows you to invert the signal in real time (under settings) and you can see what the picture should look like at the same time.


I will try Gary i have a bit of time today and will try a few things ,made a few test cards to try out for when i get it right ..let you know how i go .
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Postby gary » Thu May 03, 2012 10:59 am

harry dalek wrote:t ..let you know how i go .


The birth of a new machine - can't wait! :-)
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