Movement of reticle, and therefore POI, when camera is moved

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clivej
Posts: 14
Joined: 09 Aug 2013, 08:10
Location: Ireland

Movement of reticle, and therefore POI, when camera is moved

Post by clivej » 24 Jan 2014, 11:01

I have a simple NV set up and it's working well enough. Reticle is in focus and I can see my target.
But the problem I'm getting is if I move the camera a little the reticle will move across the target, when a let go it will return to very nearly where it was. It's like the same when you move your head and the parallax is not bang on.

I have tried moving the camera in and out a little, adjusting the parallax on the scope but it's not making any difference.
The lens is 20mm and I have a 12mm on order, could this be my problem?

What is the answer to this problem, is there one??

To try and reduce the amount of movement available I changed the camera fixture to some plumbing fittings from my last set up. This greatly reduced the amount of movement but if the fittings are pushed at all the POI will still move.
viewtopic.php?f=29&t=5671

This is my set up now.

Image

Image

m_pragnell
Posts: 315
Joined: 22 Nov 2012, 23:11
Location: Torquay

Re: Movement of reticle, and therefore POI, when camera is m

Post by m_pragnell » 24 Jan 2014, 14:00

What your describing is parallex error, I'm sure someone will correct me but you just have to make sure the camera is as stable as possible, if you've got masking options on the camera you could set up a cross hair or dot over the scopes reticle and at least you can see if it's moved and move it back before taking the shot

terry1001
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Location: Ipswich, Suffolk

Re: Movement of reticle, and therefore POI, when camera is m

Post by terry1001 » 24 Jan 2014, 19:11

Difficult to tell from the photo but you should find that a reasonable position for the camera is so that there is about 38/40mm between the rear scope lens and the front of the camera lens. The camera needs to be focussed on the reticle and you should then lose the parallax errors. If your target is out of focus then adjust the scope to get it sharp, side focus scopes are easier to use than those with an adjustable objective lens.

sedstar
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Joined: 21 Apr 2013, 23:13
Location: across the pond, PA, the states...

Re: Movement of reticle, and therefore POI, when camera is m

Post by sedstar » 24 Jan 2014, 19:22

quote:" The camera needs to be focussed on the reticle and you should then lose the parallax errors"

there is always SOME parallax, when we say "no parallax" we probably mean to say "parallax is at a minimum"...

getting the thing as sturdy as you can get it will cure what ails you, as well as good focusing of the main objective and eyepiece.

this is what i like most perhaps about the "rolaids rail" build... a very sturdy thing.
Well, I understand that, boys... but see, my CAT gets the silly idea you're making fun of HIM... then he gets, *really* mean...

clivej
Posts: 14
Joined: 09 Aug 2013, 08:10
Location: Ireland

Re: Movement of reticle, and therefore POI, when camera is m

Post by clivej » 24 Jan 2014, 19:38

sedstar wrote:quote:" The camera needs to be focussed on the reticle and you should then lose the parallax errors"

there is always SOME parallax, when we say "no parallax" we probably mean to say "parallax is at a minimum"...

getting the thing as sturdy as you can get it will cure what ails you, as well as good focusing of the main objective and eyepiece.

this is what i like most perhaps about the "rolaids rail" build... a very sturdy thing.

Thanks for all the reply's.

I found when I had the 'Rolaids' long picatinny rail set up there was more movement and went with the plumbers fittings that I found to be very solid. From what your saying I seem to have it about as good as it gets.

I think over the distances that I will be shooting, say a max of 300m, the parallax movement will be only a couple of inches, at most, and as my Point Blank Range will be 2" - 3" the movement is acceptable as is.

sedstar
Posts: 1354
Joined: 21 Apr 2013, 23:13
Location: across the pond, PA, the states...

Re: Movement of reticle, and therefore POI, when camera is m

Post by sedstar » 25 Jan 2014, 03:52

you can "sturdy up" a rolaids rail further? by using TWO scope mounts to hold the rail, instead of the usual just one... i can usually only locate 4 scope mounts though... 2 front, rear... 1 each is for holdin the SCOPE one (duh, lol) leaving TWO more...

then, my screen takes one of the two left...lol

i guess if yu locate the screen and the IR light onto the rail?? you can use 2 scope mounts to get a really sturdy rolaids rail build...

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for what its worth? you can get some movement out of most scopes, just by applying steady finger pressure, and watch the POI move a bit... it goes away whenn your finger pressure disappears though...

if the POI movment with gentle finger pressure "goes back" when you release pretty well? I'd call it a blazing success.

also? remember that the rail (OR your no-rail coupling, lol) is a TORQUE ARM adn the laws of physics ever apply. Just like a LEVER, a jack handle, a tire iron, or a "cheater bar" to remove a stubborn bolt??

the increased LENGTH makes it more susceptible to induced pressure movement, and lowers the force required to get movement out of the system.
Well, I understand that, boys... but see, my CAT gets the silly idea you're making fun of HIM... then he gets, *really* mean...

clivej
Posts: 14
Joined: 09 Aug 2013, 08:10
Location: Ireland

Re: Movement of reticle, and therefore POI, when camera is m

Post by clivej » 26 Jan 2014, 13:48

As with all things in this house I only seem to get a few minutes to works on anything 'Of Mine'.

Went at this again today and found that everything 'as is' is working very well.
My POI issue was/is in fact my wrong doing. It was not the camera that was moving but the complete scope and camera moving in the ball joint of the cheap ALDI clamp on vice that is clamped to the window board to view out of the window.

If I take the camera out of the plumbing fitting and move up/down or side to side the POI stays on target as it should.

Next step now is to tidy it all up and wait for the 2 other lens I have coming, both a 12mm & 16mm, then see what view I prefer.

I connected my amp meter up and see that the camera and screen are taking 4amps. Is that about right????

Radagast
junior librarian
Posts: 2617
Joined: 04 Apr 2013, 10:51
Location: Sydney Australia

Re: Movement of reticle, and therefore POI, when camera is m

Post by Radagast » 26 Jan 2014, 14:32

Wrong answer, thought the camera was an E700. Please ignore.

phoenix
BRUCE ALMIGHTY
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Location: Aberdeen

Re: Movement of reticle, and therefore POI, when camera is m

Post by phoenix » 26 Jan 2014, 17:35

I connected my amp meter up and see that the camera and screen are taking 4amps. Is that about right????


NO!!!
You sure it's no 0.4 amps

Cheers

Bruce
LAND ROVER - THE WORLD'S WORST 4X4 BY FAR

clivej
Posts: 14
Joined: 09 Aug 2013, 08:10
Location: Ireland

Re: Movement of reticle, and therefore POI, when camera is m

Post by clivej » 26 Jan 2014, 22:06

phoenix wrote:I connected my amp meter up and see that the camera and screen are taking 4amps. Is that about right????


NO!!!
You sure it's no 0.4 amps

Cheers

Bruce
Thought it was a little high myself.

Checked the connections and had them wrong on the multi meter and it's .22 amps that's better I can live with that.

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