Mogg adapter UWAS-F with Focal Reducer

QCUIAG member Steven Mogg also makes fine adapters for Philips Vesta cameras AND even Focal Reducers (FR) for wide view imaging! This FR can be screwed into the threading of the UWAS-F adapter.
Related issues: using the Focal Reducer required a special Very Short eyepiece holder and the Focal Reducer of course also changed the Field Of View (FOV) and f/ratio

Slow Motion Controller 'Witty'

I bought this little piece of equipment (Witty) to be able to correctly aim my SLR Photolenses with camera while piggy-backed on my telescope as well as in combination with my standard photo tripod.

There are 3 controls: one to coarsely adjust the tilt and two turning knobs to precisely control the movements in vertical and horizontal direction.

Supplier: Teleskop Service - München

SLR Photolenses and other lenses

This is my "arsenal' of SLR Photolenses, all bought second hand at low prices [the 200, 300 and 400mm SLR Photolens have changed hands].
All my lenses have M42 'P-thread' and my SC3 cameras have a ring with M42 threading so that mounting is easy, secure and interchangeable.
I can use these lenses piggy-back on my LX200 telescope
I have made a set of Dew Shields from a camping mat.

How to determine the focal plane of a lens

  • Take the lens in your hand and aim at the sun (do NOT look through the lens !!!!).
  • Now you have what boys call 'a burning glass'.
  • When you move the lens up and down you will see that the spot of light that comes out of the lens gets smaller or bigger.
  • When it is at its smallest you have found the focal plane.
  • Use a calliper to measure the distance from the back of the lens to the bright spot and you know where the focal plane of your lens is, and thus the exact distance between your lens and the CCD sensor.
Aligning an SLR Photolens with the rest of your set-up (main scope and finder) always took me a long time, especially when using an SLR Photolens with long focal length. I have solved this by using a ViewFinder
Click here to see my table with the Field-of-View and Focal Length

Closeup of my 85mm f/2.8 lens, most likely salvaged from a slide projector.
Obviously I must clean the lens ...
The 85mm f/2.8 lens with Scope Teknix Filter Wheel and ATK16IC camera installed on home made piggy back rail
Rigel and surroundings; test image.
January 16, 2008 20:48 UT.
I used a very short clear spell to find out how my 85mm f/2.8 lens - most likely salvaged from a slide projector - would perform under the stars when combined with my filterwheel and ATK16IC camera
Yesterday I had spent several hours during daylight to arrive at the proper lengths of the barrel holding the lens and the M42 ring I wanted to attach to the barrel.
A disadvantage is that the lens has no focusing capabilities itself so I must rotate the lens in the T2 threading of the filterwheel, which seems to work.
Because of the very limited time - clouds were arriving much too fast - I could do no precise focusing, but the results are promising.
FOV [calculated and confirmed by measuring on the stars]: 193.82 x 145.37 arc minutes.
Imaging: 85mm lens, ATK16IC camera, Astronomik L filter.
Exposures: L: 2x30s; RGB: not imaged; unguided.

The three belt stars of Orion together with the Flame Nebula and the Horse Head Nebula
January 24, 2008 21:16 - 21:52 UT.
The three belt stars of Orion together with the Flame Nebula and the Horse Head Nebula.
This image was a test to see how the 85mm lens [ex slide projector] would perform.
Imaging: 85mm lens [ex slide projector], ATK16IC camera, Astronomik H-alpha filter, 10 unguided exposures of 240 seconds.

The same area according to Megastar.

My 6 inch f/8 telescope fitted with 2x teleconverter and 2x Vixen HQ Barlow operating at f/32.
Example image: the Clavius image of March 3, 2004 (Moon details pages).

My Coolpix 995 and my SLR Photolenses.
From left to right:
- 300mm SLR Photolens with standard M42 thread [outside]
- standard TAL-2M eye piece adapter with M42 thread [inside] and 1.25 inch diameter on the other end
- standard William Optics DCL-28 adapter including 24mm eye piece and 28 mm thread [outside] for the Coolpix 995

Because of the weight of the [300 mm] SLR Photolens I have made a supporting [piggy back] platform to reduce the strain on the neck of my Coolpix 995.

Zooming in on my observatory:

Coolpix 995 with own lens and max. wide.

Coolpix 995 with own lens and max. tele.

Coolpix 995 with 300mm SLR Photolens, DCL-28 and max. tele.
July 11, 2005.
Field of view of 300mm and 400mm SLR Photolens with SC3 camera when imaging the whole disk of the sun or the moon.

ToUcam lens on SC3 camera

I wanted to use my SC3 cameras also with the original webcam lense, so that I would have a really wide field-of-view.
Matthias Meijer had a surplus ToUcam lens holder, in which I inserted a ToUcam lens. When holding it by hand in front of the CCD it would focus :o)
After some thoughts I dug up the unused nose of a Vesta and shortened it with a sharp knife so that it exactly fitted in the front hole of my camera.
The beauty is that I can still focus by rotating the ToUcam lens as originally designed, nothing unconventional about this.
Aperture: about 2mm, focal length 5.8 mm
FOV: 46.8° x 35.08°

USB - Serial - Parallel Adapter

Sweex USB - Serial - Parallel Adapter [1]
As bought in a local shop

Sweex USB - Serial - Parallel Adapter [2]
Modified as per Matthias Meijer's instructions and built in a project box.

Zenith Mirror

1,25" 45° Zenith mirror

1,25 inch Filter Drawer [home made]
** Meanwhile replaced by my Scope Teknix Filter Wheel **

Aiming my setup with an SLR Photolens/H-Alpha filter combo at a dim object is hard, and I found it *VERY* disappointing - when after having done all that work - to loose the object while searching for a guide star with my previous scope (see my TAL-2M Autoguiding Tutorial)

So I have been thinking how to make life easier for me: obviously it was necessary to temporarily remove the 1,25 inch H-Alpha filter from the optical path and insert it later when the actual imaging would start (I need the H-Alpha filter to reduce the effects of my local light pollution).

I searched the Internet and found this commercial solution (site is in German); costs ca Euro 130
As I wanted to avoid spending this amount of money I searched for an alternative ...

I remembered I had a M42x1 threaded macro ring in my goodies box:
it was exactly the height (19mm) I need to achieve focus with my SLR Photolenses and it has M42x1 male and female thread.
I was rotating this ring in my hands and planning how to make a drawer inside it when my good friend Kees Molders e-mailed me: he already had transformed the same kind of ring into a filter drawer! What a coincidence.
My solution can be viewed in the following images; Kees selected a different approach.
I went to the DIY shop and bought a 32mm PVC tube bracket: Euro 0,75.
With a hacksaw I made it a lot smaller and I inserted some felt (with self adhesive layer) inside the bracket to get the proper size, so that it would hold my 1,25 inch H-Alpha filter.
I put some felt on the outside of the bracket to minimize light leakage
With hacksaw and file I made a - more or less - rectangular hole in the macro ring, through which the bracket-with-filter would slide in and out the optical path.
It took me all afternoon: working metal is not my favourite occupation ...
In the meantime I have applied a layer of non-reflective black spray.
When the bracket finally fitted in the ring I put some felt on the outside of the bracket to minimize light leakage.
Tests have shown that the felt sufficiently blocks the light.
August 11, 2005. First test results. The object is NGC6960.
Exposure 60 seconds, H-Alpha filter inserted in filter drawer, autoguided.
Seeing: fog building up rapidly, but I just wanted to do the tests.
August 11, 2005. First test results. The object is NGC6960.
Exposure 75 seconds, H-Alpha filter inserted in filter drawer, autoguided.
Seeing: fog building up rapidly, but I just wanted to do the tests.
August 11, 2005. First test result of dark frame, to see if any light was leaking. It seems no further action is required.
Exposure 75 seconds, H-Alpha filter inserted in filter drawer.