A result....kinda

[EA2007]

Hey kids,

sorry if there's some typo's in this piece, I currently have cold and well my brain doesn't work too well when that happens, like last year I had glandular fever and had real trouble playing tetris or doing simple math (bit like Hammond on TopGear when he's in the cold!!)

Anyway.....a few months ago someone kinda said that if I whacked a lump of wood on the underside of my primary on my newt. then I could solve the issue of it not allowing a dSLR to focus.

Having tried on random occasions to see where eactly the focusing point was, I had to remove the 3inch high focuser and hover the camera over the open hole on the side of the OTA to realise the focusing point was about 2cms from the hole. SO to solve the problem I would either need to buy a well expensive new slimline crayford, even then it might still be too high............or..........but a new scope................or a new camera...................or build a new focuser...................or.......give upr completely.

However I tried out the 'wooden block' idea with a humble tea coaster and well the focusing point is near perfect with the focuser still attached to the OTA, so I am thinking if I can get some longer screws for the primary then I can insert another coaster..........or something more substantial and the focusing point will be higher away from the OTA, thus meaning that I can use my dSLR with the t-mount and adapter and slot it nicely ad securely into the 1.25 EP hole.

Fun !

As a reward for you reading all this and wasting about 3 minutes of your life...I shall give you a reward, Fact: the torpedo's that were dropped on Pearl Harbor were made by Mitsubishi!

[daz]

This is the dilemma that newtonian owners face when trying to bring a DSLR to focus. Use a lower profile focuser, or move the mirror!

Good to see you got a result EA - just make sure the mirror is fully supported

[EA2007]

Its 'nearly' sorted, lol.

I just need to find a more secure 'block' and some longer screws, but I am confident it will work. May need re-collimating though.

[darditti]

Bear in mind you may loose the light from the edge of the mirror when you move it up.

As seen from the focal plane (where the eyepiece would go when in focus), if the whole of the primary cannot be seen reflected in the secondary from a fixed point, i.e. the reflection of the primary has got too big because you have moved it up the tube, then you have effectively reduced the aperture of your telescope and increased the f ratio.

This is a general problem because commercial Newts are optimised for visual use, not photography. For photography you optimally need both a smaller mirror spacing and a larger secondary.

However, the loss of light may not be important. You will certainly need to recollimate.

David

[EA2007]

Good points there, I am only moving it a little way so not that much, hopefully all will be well.