Mirror Camera project

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Re: Mirror Camera project

Postby Harry Dalek » Thu May 15, 2014 3:21 pm

At last had some time to look into this again,last i tried i had a lot of motor noise picked up in the head amp so after trying using battery supply for the head amp this has cut the noise problem right down .
Any signal would of been washed out in motor noise .

The relay does not seem to effect it .

On the 400 hz motor perhaps a brush less motor might be a better solution for a motor which the polygons was when it worked .

Next try the new op amps see how that gos i might have to have it on the head amp battery if i still have noise in this section any cased slowly slowly catch the monkey . :wink:
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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Re: Mirror Camera project

Postby AncientBrit » Thu May 15, 2014 5:30 pm

Morning Harry,

Fascinating reading your experiments.

Keep up the good work.

Not sure how you find the time for all this plus work!

Cheers,

Graham
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Re: Mirror Camera project

Postby Harry Dalek » Thu May 15, 2014 8:45 pm

AncientBrit wrote:Morning Harry,

Fascinating reading your experiments.

Keep up the good work.

Not sure how you find the time for all this plus work!

Cheers,

Graham


Hi Graham

OH i don't work Thursday Fridays unless something comes up job wise .

So i have those days and the weekend most times to fit some experimenting in and the wife is kind to my strange ways :mrgreen:

I Hooked up the head amp up to the video mixer with the new op amps they seems ok ,i think i still need a volume control in there as even with the line input its way up there.

I had the circuits all on a 12volt power supply and the head amp on battery in the animated gif below i had the lights on and tv on doing this so i expect theres noise in the signal on Garys Big Picture scope ,if theres a motor spike there i will have to have a battery just for the video mixer and head amp so the positive power rail is not carrying motor noise to my circuit.

All i can do is try my best to fix any problems i think i have and try and see how it gos . :|
Attachments
P1060774.gif
Trying the head amp with the video sync mixer
P1060774.gif (11.4 MiB) Viewed 3238 times
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Re: Mirror Camera project

Postby AncientBrit » Thu May 15, 2014 10:25 pm

Hi Harry,

3 day week!! Not bad.

Happy experimenting,

Cheers,

Graham
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Re: Mirror Camera project

Postby Harry Dalek » Sat May 17, 2014 11:36 am

AncientBrit wrote:Hi Harry,

3 day week!! Not bad.

Happy experimenting,

Cheers,

Graham


Yes i like the short week it sort of helps with the kids as well .

Yes i am back at it today ,i don't think theres to much wrong with most of the electronics side ,the things i expect now might be a problem i may encounter is perhaps is optics strength of the head amp and the vibrating side .

I am thinking it might be wiser for a start unless i get promising results to start with to perhaps use a slide or a template shape at the lens and use a bit more light behind it as in some projects i have read about in past news letters side still camera .

Going to place the head amp in today and see how well it sees via the lens side of things.
Attachments
P1060780.gif
reflecting test
P1060780.gif (13.49 MiB) Viewed 3215 times
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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Re: Mirror Camera project

Postby Harry Dalek » Sun May 18, 2014 10:14 pm

This week end was another step back and a step forward .

Playing around with the mounted head amp i had made i could see its far to weak for natural light which i would rather it do .

I started working on another head amp but the results were a again a bit disappointing .

So i decided to make a copy of the head amp i had used in the flying spot camera project it has no hidden nasty oscillations and works near on no light to full with out problems .

I have yet to use it with a photo transistor or diode but its pretty good on a solar cell test .

I will post it below its by Doug Pitt i think its far superior to the club head amp and far simpler also far simpler to trouble shoot .

I used BC107s i had left and all i had to do due to using those was change the 2.2meg to a lower value around 500k .
Attachments
Screen 00000.jpg
best head amp
Screen 00000.jpg (62.29 KiB) Viewed 3200 times
P1060788.JPG
bit messy form of construction but it works
P1060788.JPG (386.96 KiB) Viewed 3200 times
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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Re: Mirror Camera project

Postby Harry Dalek » Wed May 21, 2014 11:16 pm

Been interested in making a few of the same head amps with different light sensors i had handy to test the sensors in the camera.
I got a few free sample surface mount ic pcb boards so using those to do a few head amp surface mount circuits ,learning to do it less messy as i go not meant for what i am using it for but what the hell .
I want to make at least one more using an led the latest one i am not sure what that is seems sensitive to room light room lighting tv and such .
The solar cell is best due to its surface area, the light sensitive trany and diode are what i need very directional and give good results with this circuit.

Funny enough i have not found a plastic type trany that works as good as the old can type transistors ,Bc548 closet so far.
Attachments
P1060796.JPG
ones made so far
P1060796.JPG (438.35 KiB) Viewed 3166 times
P1060797.JPG
latest head amp
P1060797.JPG (332.94 KiB) Viewed 3166 times
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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Re: Mirror Camera project

Postby Harry Dalek » Sun May 25, 2014 9:16 pm

Have not had much time this week ,did some work today aligning the first head amp for testing.

Thinking of putting a little cover around the light sensor so it doesn't pick up stray light from the sides .

Heres a picture or 2 of it mounted .
Attachments
P1060798.JPG
diode light sensor head amp
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P1060800.JPG
P1060800.JPG (353.37 KiB) Viewed 3132 times
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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Re: Mirror Camera project

Postby Harry Dalek » Mon Jun 02, 2014 7:49 pm

Experimenting last weekend i can see i have a bit of work .
Posting here a wav file i was just shining a light at the lens see if i could make the bulb out.
I can see my sync has been inverted ,i'll have to fix that .
I also think the optics is off the light sensor is picking up light from the sides more than likely not focused correctly at the front .
Reading past news letters i can see they have used either a lens or a mask hole at the light transistor for some thing like this ...
so i am looking more into this ...

I will make sure what the light sensor see's is tiny see how that gos .
Attachments
globe.wav
(2.73 MiB) Downloaded 118 times
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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Re: Mirror Camera project

Postby Harry Dalek » Wed Jun 04, 2014 8:58 pm

I tried an experiment today to see which of my 3 types of light sensors work best in the low light levels .

I am sort of copying this idea in the drawing below...as in the pin hole camera part idea.

I enclosed the sensors in a light proof box for the solar cell and a light proof cylinder for the light trany and one also for the diode all only had a pin hole for the light entering ,the solar cell i have to say was many times more sensitive i am not sure if its because this head amp circuit works best with a solar cell or they are more sensitive .

One funny thing i now know because i used a little play dough on that back of the photo diode to light proof the back is it shorted out my diode, i promptly swapped to glue tack which am happy report is non conductive. :D

Reason i tried this today is the light levels drop passing the lenses in the old video camera lens i am using and there was a bit of difference reflecting light from the mirrors via that lens than with out it ,it was enough to cause problems on lower light levels ,i am a fussy bugger so time for a redesign.
Attachments
Screen 00002.jpg
mirror drum camera
Screen 00002.jpg (22.63 KiB) Viewed 3084 times
Last edited by Harry Dalek on Fri Jun 06, 2014 2:20 pm, edited 1 time in total.
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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Re: Mirror Camera project

Postby AncientBrit » Wed Jun 04, 2014 10:35 pm

Hi Harry,

That's an interesting observation about play dough being conductive.

Might find a use as a conductive sealing gasket on a box.

Keep on going Harry!!

Cheers,

Graham
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Re: Mirror Camera project

Postby Harry Dalek » Thu Jun 05, 2014 10:04 pm

Thanks Graham

I pinched a bit of that stuff from my kids i was thinking it was an easy fix little did i know :roll:

Yes i am back at it today i have to stay focused and learn from my mistakes ,its never as easy as you think from a design in your head ,The optics part is the hard part for me never been good with lenses .

So been looking at this again in my design and i changed things around a little to make sure i was seeing all the lens or enough at least to make this work.

I will post some light reflecting result tests today just to make sure both axis movements are doing the job.

The solar cell will replace the photo diode tomorrow ,i will encase and try it with a pin hole only for light this way i know as the polygon sweeps across it it will only see a spot of light ,perhaps if it gos well i could replace the pin hole with a dvd laser lens for more light
Attachments
P1060815.JPG
turned around the position of the axis movements
P1060815.JPG (336.12 KiB) Viewed 3074 times
P1060816.JPG
P1060816.JPG (352.93 KiB) Viewed 3074 times
P1060813 (1).gif
frame movement to polygon
P1060813 (1).gif (5.42 MiB) Viewed 3074 times
P1060818.gif
lens to frame mirror to polygon
P1060818.gif (4.15 MiB) Viewed 3074 times
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Re: Mirror Camera project

Postby gary » Thu Jun 05, 2014 10:52 pm

Harry I am probably going to make a goose of myself here but my excuse would be I am having trouble interpreting your images, also it maybe you are just trying to show the light path in some way I don't quite understand, but whilst the direction you are showing the beam of light is correct for when it is operating as a camera, surely you would want to reverse that (i.e. from the source to the line scanner to the frame scanner). That way you would project a raster on the area you would be "scanning" when in camera mode ( or "spotting" if in FSS mode). If that raster is correct then the reverse (i.e. camera mode) would be correct.

In other words there is a "duality" in this type of system whereby if you replace the photo detector with a light source you change a camera into a projecting monitor (or FSS if the light source is unmodulated) - and vice versa.
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Re: Mirror Camera project

Postby Harry Dalek » Thu Jun 05, 2014 11:44 pm

gary wrote:Harry I am probably going to make a goose of myself here but my excuse would be I am having trouble interpreting your images, also it maybe you are just trying to show the light path in some way I don't quite understand, but whilst the direction you are showing the beam of light is correct for when it is operating as a camera, surely you would want to reverse that (i.e. from the source to the line scanner to the frame scanner). That way you would project a raster on the area you would be "scanning" when in camera mode ( or "spotting" if in FSS mode). If that raster is correct then the reverse (i.e. camera mode) would be correct.
In other words there is a "duality" in this type of system whereby if you replace the photo detector with a light source you change a camera into a projecting monitor (or FSS if the light source is unmodulated) - and vice versa.


Hi Gary
No goosing here :wink: thats my job Whoops i should explained my self more .
Yes i am trying to show the path of the light so i can see if i have the optics about right, done it a few times the other way in projecting but this is a different kettle of fish for me .

Yes again Gary i would rather the line polygon first but the polygon mirror is very thin its easier to project from the lens to the frame mirror then to the line then to the light sensor , also because of case and where the lens is its just working out better to reflect off the frame mirror

The camera is laying on the side so the line mirror would be upright when working in NBTV format.

I was thinking about testing both mirrors working in a Flying spot test just to see if the vibrating side of it works i sort of was going to do that a few days ago i was going to use the laser i scrapped from the brother laser scanner but it was dead i was not happy !
It would of been nice to see a raster.

So of late i have been trying to work out experiments to make sure my sensor only sees a spot of light from the polygon as it sweeps by the sensor...i think working on this i see theres a bit of unwanted light scattered by the mirrors and i suppose entering the camera via the lens , a Nipkow perhaps blocks a lot of this more than one of these do.
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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Re: Mirror Camera project

Postby Harry Dalek » Fri Jun 06, 2014 1:29 pm

Since Gary posted i feel i might not have explained the idea and experiments to try and get this right for my 2 mirror camera idea .

I will post some drawings below sorry bit messy .

With the 2 mirror camera system it is obvious i need to reflect an image from the lens to brake it up into a scanning method in 2 directions .

In the first drawing due to using a full mirror no masking a full line is reflected to the polygon mirror face so a full line is reflected to the solar cell in a light proof case with a pin hole to only see a part a dot of light as the polygon turns and sweeps past the light sensors pin hole opening.

So the above is what i a hoping for to work with a 2 mirror system its just like a deconstructed mirror drum depending on the speed or either mirror you could have many different television formats all depending on line and frame speed which i rather like ,there are limitations depending on number of mirror faces and motor speed .....still .
Alan short made a Slow scan tv camera with the same sort of idea and many NBTV versions over the years .

Now on to the second idea of having either a thin mirror for the frame and thin line mirror in this case depending on the size thickness of the thin mirrors and or masking you would get a similar result to what Gary was getting at like a flying spot camera in reverse ,you would not get a full line of light but a moving dot and perhaps not need a light proof case ? not sure as i have not tried that with one of these yet .
I think its a matter of Persistence and trial and error see if i can do it .
Attachments
P1060819.JPG
Line of light reflected like a mirror drum idea
P1060819.JPG (226.41 KiB) Viewed 3065 times
P1060821.JPG
Thin mirrors or masked mirrors give a fly dot of light
P1060821.JPG (241.66 KiB) Viewed 3065 times
P1060822.JPG
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P1060823.JPG
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P1060824.JPG
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P1060826.JPG
P1060826.JPG (307.47 KiB) Viewed 3056 times
P1060827.JPG
P1060827.JPG (337.41 KiB) Viewed 3056 times
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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