focusing webcam ?

[Charlie_132]

Okay thankyou, my aim is to get it working by the time it gets dark so I can take some photos of saturn, the star next to it, jupiter, venus and mars

[dav1d]

Right. have a look at this. Just made it in the back yard to show what you need to move and what you don't.

I did it on my wife's camera phone so quality / videography is poor, but hopefully it should help

2012-04-07 11.12.00.3gp - YouTube

[Charlie_132]

thanks for the video, i just tried it, still no image though, stayed as a blank white screen

heres a photo of my webcam in the scope (my finder scope is on the right, just i took it with my webcam built into laptop as its easier to upload)

[dav1d]

Blank white is all you'll get until it's in focus. What were you trying to focus on & how far away?

[Charlie_132]

ohh and how do i focus it ?

that is turning the eyepiece isnt it ?

and about a chimley 100 meters away

[dav1d]

You focus it by shortening the telescope tube. 100m is probably too close and a chimney is easy to lose, because the scope moves a bit as you adjust it - very easy to end up looking at the sky by accident. You have to remember that the sensor in the cam is tiny and gives a very, very narrow field of view.

If you can, try it on the brickwork of the house and then move up to the chimney.

By narrow field of view, I mean that at 100m, the cam will be looking at an area of about 1 square foot or less - you'll see maybe a couple of bricks.

Best target would be the moon tonight - it's pretty hard to miss. Don't even think about Saturn just yet - I can just about manage to get Mars into shot & still haven't managed Saturn.

[Tiddles]

When you extend the OTA, do not extend it fully.

[sytra]

I don't know how relevant this is, but i had a problem with my SPC900 and couldn't get focus or see anything but a blank screen a few weeks ago.

Dont know what made me try it but i focused the scope onto a really bright light popped the camera in and bam it worked, next day it refused to work again, so shone a torch briefly into the OTA, screen went a bright bright white but the cam worked from that point and has worked fine since, i dont know how or why it worked but for me it did.

Like i say probably totally irrelevant.

Simon

[Charlie_132]

Oh I'm a little confused now

Do I just put the webcam in so the eyepiece holder is screwed right to the bottom, then to focus on a object and move the telescope pole thingys all the way out to all the way in until I get a picture on my laptop ?

[Tiddles]

It is likely that the focus point is only just out of reach, do not extend the truss poles to full extend, leave an inch or so then try to focus as before.

[Charlie_132]

So basically aim at a object

Move the poles in and out until I get a image on screen. So I don't touch the eyepiece holder atall once the webcam is screwed in

[dav1d]

Oh I'm a little confused now

Do I just put the webcam in so the eyepiece holder is screwed right to the bottom, then to focus on a object and move the telescope pole thingys all the way out to all the way in until I get a picture on my laptop ?

Yes - assuming that by all the way out you mean so that the scope is fully extended. And you wont need to move them all the way in - a few inches should do it. And move them slowly...

[Mr TamiyaCowboy]

sw 130 heritage is on truss legs.

put webcam into eyepeice holder. just pop it in and start sharpcap, Do not worry about settings.

watching your screen. undo you leg clamps, as your packing the scope down.

let them slide downwards go careful.

As you are moving the truss legs downwards watch the screen, you should start to see a picture forming. if the image is upside down just rotate the webcam in the eyepiece holder.

what you are doing is moving the two mirrors closer to each other, this shifts the focal point so your webcam can see an image. it is abit like using the focuser but more extreme as you are moving the mirrors closer to each other.

[dav1d]

What Mr TamiyaCowboy said.

[Charlie_132]

I've done that and still nothing ... White screen

[dav1d]

OK. Wait for tonight & try it in the moon

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[Charlie_132]

Okay then. It it doesn't work on the moon tonight probably going to beed to sell it again as I won't be able to get any results with it

[JamesF]

You should be aware that if you're trying to image a planet, if you find it with an eyepiece and get it nicely centred in the view before swapping to the camera then you have only a matter of a few seconds before it will drift off the camera sensor due to the rotation of the earth. How many depends on the scope and whether you're using a barlow, but even with no barlow I doubt it will be much more than ten seconds. What you're trying to achieve is not easy and if it doesn't work it's not likely to be the camera that is at fault. With a planet you could quite easily have it right under the red dot in the finder and still have the camera miles out.

If you're focusing on a chimney for testing, the scope only has to be out by a fraction (a tiny wobble when switching from eyepiece to camera would be sufficient) to be pointing at the sky. Starting with something much larger that you absolutely can't miss would probably make things easier. Even if you have the red dot finder perfectly aligned so that something is spot-on in the middle of the view through the eyepiece, you shouldn't assume that means it will be bang in the middle of the camera sensor.

James

[Charlie_132]

I should be able to pick up distant houses that I can see through a eyepiece with a webcam though ? Not just white ?

[JamesF]

As long as that's what the webcam "sees" when you swap it over. One of the difficulties with doing this is that if the webcam is too far out of focus then you just can't see any detail at all.

If you start up sharpcap without putting the camera in the telescope, does the image go dark when you put your hand over the end of the camera? That would at least make sure that it is responding to light.

James

[Charlie_132]

Yeah it goes dark if I put my hand over the end of it

Put any time I put it in the eyepiece I can only get a blank white picture ... Nothing else atall

[dav1d]

That's good. It means it's working and is de-lensed. The advantage of waiting for tonight is that the sky is dark and what you see through the can will be dark EXCEPT the moon, so it'll be easy to know when you have it lined up. When you have the moon lined up and the screen is white, then adjust the tube as in my video.

If it doesn't work, try again and again until it does.

Patience is a virtue.

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[Charlie_132]

Yep that's the plan tonight, its a massive advantage that that moon is in the east as my bedroom window looks east, so I can do it from the warmth of my house

[Charlie_132]

Only problem tonight is the sky ... Bbc said it would be clear 10 - 1am but now its cloudy ... Tuesday should be clear, just frustrating if I can't focus on the moon still

[Mr TamiyaCowboy]

hey charlie

you do not have to have the moon out, just getting a focused picture is what we need to do.

how i done mine.

first i checked cam was working, hand over the cam and a dark pictures means its on the ball.

next pop the cam into the eyepiece, at this time i popped an endcap on to check for a dark screen again. i pointed to something big a nice red house roof or a brick wall. locked telescope tight so any movement was in AZ ( left-right)

now with one eye on the screen and one on the job in hand, i adjusted the cam ( for you the lelescope truss legs) back and forward. this took me ages but in the end i got a fuzzy'ish picture.

then i went to sharpcap. i dropped the picture brightness and lowered the exposure a little . the now fuzzy image started to become more clear. with final slow tweeks on the focuser, and little messing around with settings i had a nice clear'ish picture.

the picture below is from my MS 5000hd webcam on a skywatcher 76 ( little brother to your version). so keep at it, when it niggles you pop in an eyepeice and view, when calm return back to gaining focus with the cam.

its a long painful slog tweeking here moving scope there, but it is worth it in the end.

my skywatcher was shortsighted. try unscrewing eyepiece holder popping cam in, then adjusting the truss legs in and out. try all possible combinations. i found i could focus in on object very close ( 8-10ft) but nothing far away. i have to webcam without my eyepiece holder in, it gives me 5mm extra play and allows me to snap to focus