What to do with an old camcorder-Infrared

[Spanrz (Brett)]

I had an idea the last few weeks, that was to somehow attempt for experimentation purposes, an infrared camera. Night sky watching, see if it will pickup Satellites but most of all, the attempt was for ISS/Shuttle tracking etc etc.

I watched some Youtube vids, that showed that you can mod webcams and the like, to accept Infrared light.
Basically you have to pull apart the webcam/camera and remove the IR blockout filter that is near the sensor/lens and then reattach without stuffing it up.

I did that tonight, pulled apart an old Hi8 camcorder, with pure gumption(even after the Mrs went ), I got it apart, undid the lens, and found the blockout filter. Removed filter, put back together, to find out that the auto focus system didn't work.
I had knocked the system out of it's home position and it didn't move after I put it all back together.
Had to repull it back apart to understand why it failed. After 30 minutes, I found it doesn't like to be reset/not in the home position type of thing.
Finally got it to accept the home position and put back together.

Took it outside to see what it could see against my IR security camera and it worked a treat. Absolute magic. The IR LED's illuminated my hand that was infront of the camera.
I could see my hand without any issues (in complete darkness).
It even picked up some stars with it

Though it had one quirk/trade off, since the filter was taken out, Auto Focus isn't all that great.
You have to zoom slowly to auto focus. So this will be a challenging aspect of this mod.
I just need now, a proper IR illumination spotlight and away we go.

What a way to recycle old cameras. Camera that was used : Hitachi Hi8 Camcorder (year 2000 vintage)

[citivolus (Ric)]

If you replace the filter with a similar thickness of plain glass, the auto focus may work

[sheeny (Al)]

IR will focus in a different position to visible light. A couple of my old OM lenses have the manual offset marked on them for IR work.

I suggest manual focus will be the best you'll achieve unless you are cluey enough with optics to find and fit an appropriate correcting lens.

Al.

[koputai (Jason)]

Can you disconnect the mechanism and just manual focus?

Cheers,
Jason.

[kinetic (Steve)]

Brett,

as you know, one advantage/disadvantage of CCD sensors is
they are sensitive to all visible bandwidths and quite deep into the
IR as well as UV.
This is great for astro work because of the Hydrogen Alpha being
up in that IR. But it's downside for daylight cameras and handicams is
that the lenses have trouble focusing all of that at once on the chip.
Webcams for example will focus the RGB well but the IR still coming
through if you remove the IR filter will make the IR component of a star's
light blurred on the chip. It has a different focus point.

I pulled a few handicams and webcams apart years ago to test their
IR filters. Not all IR filters work the same. Depends on whether they
are interference types or not. One type is a greenish glass/plastic and
the other are a red tint.
About halfway down this page is a comparison of filters using a cheap,
rough webcam spectroscope.
http://jfbo.webs.com/cdspectroscope.htm

Also attached is a star image with and without the IR filter.
Note the IR unfocused halo. This is from an M type star, one with a
lot of red and IR light. Note the tighter focus on most stars
also with a filter. I took this through a modded webcam.

Steve

[Spanrz (Brett)]

I only did this experiment, because this camcorder is a bit past it's prime, not functionally wise, just practibility wise (harder to get the data off).
And I just didn't want to part with some $$ on an untested camera that may not have done what I wanted it to do.
So the Hitachi cam just got upped to being 1st class "guinea pig".

The new HD camcorder has now taken over, for daylight stuff, don't think I'll touch that one for a while.

Umm, didn't even fathom the thought that IR had a different focus point. Most probably why I got the focus issue.

It does have a manual override on focus, but I have to search on how to use it (as it didn't work when I tried the buttons), I might have to be in a certain mode for manual???
Failing that, I might have to put a lever on the lens, to really manually override it. haha.

Steve, this camcorder had the green/glass filter (2 sections stuck together). Is this the better of the 2 types?
In your link, it's the Sanyo style.

I tested to make sure that the glass I removed was the IR Filter.
I only guessed that it was the filter.
By pointing/clicking a remote control at the digital camcorder (switched on), then put the IR filter over the lens and vola, no white light.

One thing I am debating on, is it advisable to get a filter for IR (pass through)?
Or more to the point, do I really need a filter?
As the testing last night worked better than expected, but unsure if a IR passthrough filter will make any difference?

The only other thing I do need to look at is an IR LED system for lighting.

Learning so much from IIS!

[kinetic (Steve)]

Originally Posted by Spanrz

So the Hitachi cam just got upped to being 1st class "guinea pig".

Brett, I admire the investigative DIY streak in you

Originally Posted by Spanrz

Steve, this camcorder had the green/glass filter (2 sections stuck together). Is this the better of the 2 types?
In your link, it's the Sanyo style.

It's quite thick isn't it.....When I very carefully pulled that Sanyo
apart the filter had an obvious 'dirtiness' suspended between
layers of the filter.
It's a random scattering of something and maybe it's the anti-alias
function? Dunno.
I remember from all of the filter tests, the only one that had the
best curve for letting Ha through but cutting IR off sharply above it
was the little glass rectangular one in the cheap webcam lens.

Originally Posted by Spanrz

One thing I am debating on, is it advisable to get a filter for IR (pass through)?
Or more to the point, do I really need a filter?
As the testing last night worked better than expected, but unsure if a IR passthrough filter will make any difference?

The only other thing I do need to look at is an IR LED system for lighting.

Learning so much from IIS!

Well as your OP said, you intend to use it for IR captures, you would need
an IR pass filter similar to what the Planetary guys use to get albedo
features on Mars, see Trevor Barry's threads on Mars. $$$$

The downside would be that because most vis light is then cut and
only IR is let through at a very specific bandwidth, the exposure
needed for objects might be longer. Longer exposures ...noise?
Keep dabbling!

Steve