This is my Cookbook camera page

For more information on what a cookbook camera is go to http://www.wvi.com/~rberry/cookbook.htm

241 >>>>245

This is where I apologise to the original designers as I totally scrapped their method of making the printed circuit boards and some of the mechanical design of the camera to make my own. The components including the main control box were reduced greatly in size the power supplies being fan cooled to reduce the heat sink size. As shown above the aluminium hardware was anodised black. I already had a tank of sulphuric acid to do this for telescope components complete with the power supply to do it. I scrounged the black dye from one of the local commercial anodisers. In the front of the camera's are two removable screws to allow injection of dry gas from a canister. I never completely solved the internal water condensation of the camera problem even with dessicant so I ended up having to do this periodically to dry out the camera interior. Wrapping the camera body joints with pvc tape greatly improved the time before the camera needed drying out again. Apart from that both the camera's worked from switch on and still do several years later. Star bloating of the images is reduced because the main camera window is an infra red filter.
Why build cameras...

At the time it was a good idea for the price which was a fraction of the cost of a commercial camera and there were few of those about. Now there are dozens available but they are still very expensive.

Great fun to build with a great sense of achievment when you get your first image any body can do anything by wallet power but it is not the same.

The cameras work very well some of the images taken by other people at better locations in the world than I have are as good as any achieved by the most expensive commercial cameras. This is a picture of the camera heads plus the 245 control box, the 241 control box is similar. Inside the box looks like this,inside the 245 head looks like this and finally inside the 241 head looks like this. There is ten turn potentiometer control of the cooling current, also potentiometer voltage control of the motor pump to slow it down to a speed that does not limit the pump life. This also cuts down the pump noise. Apart from that smaller printed circuit boards,toroidal transformers,and separate screened cables for the sampling ADC are the main changes to the original design.

I have thought about simplifying the cooling system down to a smaller scope mounted tank with a heatsink or air cooling the head as the cooling piping is the main drag literally to the design.

I have also made a colour filter wheel for use with the camera's

After finding a suitable plastic spur gear this became easy to do on a small lathe. It consists of a disc with holes in to hold the filters.There are six holes but not all of them are used. A quarter inch silver steel shaft goes through the center and fits into bearings in two plates that are separated by an annular spacer all made out of aluminium.Fitted to the disc that holds the filters is a 2 inch dia spur gear. A three eights inch dia spur gear goes on a shaft through a bearing in one of the support plates to engage with this large gear so that you can rotate the filter assembly using a knob. . The end plates have matching aligned holes with the filter wheel fitted with the necessary turned aluminium adapters to hold the camera and to fit into the telescope. The filters are held in the disc by simple grub screws as it would have been a very difficult process to put filter threads into the holes in the disc and works just as well. These are a set of pictures that show its construction the first is of the whole unit. The second picture shows the filter wheel and the cover plate with its relavent gearing. The third picture shows the backplate turned out of a piece of 1 inch thick aluminium 6 inches diameter.For registration there is a peep hole in the back plate that looks at marks put on the filter wheel. A quick look with an LED flashlight shows which filter is in place but you do not need this in practice as you learn very quickly how much to rotate the knob to change filters.

Computing Power is needed with any camera

Imaging with these cameras using the LX200 or the Takahashi refractor is easy but is a severe gobbler of disc space. Originally one very basic PC ran the system but with the proliferation of dumped computer hardware during the past couple of years it was possible to separate the computing out into a network with a file server not in the observatory to hold all of the images and to use two networked junk PC's in the observatory to do the image grabbing and pointing control of the telescope.The network also has the other household computers on it as well. Network control of the telescope will be done in the near future if I get the time to write a suitable package.This will be in conjunction with a network videocam attached to the pointing computer or a direct video link to find out if the LX200 is getting its knickers in a twist with its own wiring or the trailing imager cabling. The observatory has a separate room for the gear but is still very cold in winter.

Imaging in the uk and its problems

The original images taken some time ago were very poor again not due to the camera but due to the light pollution and the British weather however I am getting better with practice.This is one of the most recent color images of M27. This is easy in light polluted conditions because it is bright. However light pollution depends a lot on the local atmospheric content of industrial pollution ,dust and also water vapour. In my location when I get westerly winds with rain it sweeps the sky clear. If after that the wind drops and I get a clear night then deep sky images are possible. with no moon . The reason for this is mainly that if the air is clean and preferably dry then there is much less reflection back of the light pollution so darker skies. Even in the better conditions it is not possible to see a lot of the deep sky that others take for granted, however the camera greatly improves on this with help from software. The images can be thought of as oil floating on water where the oil is a thin layer that is the image and the water is the background light from the sky, deep and large in comparison. If you remove the background light which can be treated as a constant then what is left is composed of the camera video chip artifacts,noise etc etc. Remove those and you have the image with a limited dynamic range compared to one taken in a deep sky location but still usable. A long time ago I realised that it was better to get hundreds of hours per year out of my hobby instead of the few hours a lot of people get out of real dark sky locations at star parties and so on. Very few of us have a home based dark sky site anywhere in the world. In the UK unless you are on some parts of the Coast or extreme northerly regions living with tens of millions of people on a small island means heavy light pollution.

The software package I have written for processing these images allows you to remove light pollution to a point,also camera artifact problems. Stacking of images can then be done to improve the signal to noise ratio. Tri-color images can be made up out of three color filtered images that are black and white sources. Any tracking registration faults in the original images can be corrected. The color M27 image above is the result of 24 images combined. Which is three sets of stack of eight per colour M57 here is very similar as shown at prime focus.This image would benefit from the use of the barlow to get the image bigger but would take a lot of work to collect enough stable images to make a usable picture. This image is processed but most of its faults are due entirely to the green component of the image which suffers from the light pollution..This is a typical example of an image with the light pollution in the background. It is also what a green filtered image would show where a red filtered one would be perfect.

1. so here is one with a suitable subtraction note the darker background now, however there is not as much dynamic range in the second image as the first but to the human eye the picture is much improved.The only way to improve the range now is to stack similar images. If telescope tracking is perfect due to feedback from a separate camera used to track a reference star then image stacking is easy and it is possible IF you were taking images in a perfect dark sky to stack 200 images. There is no way I can do that so up to twenty is my real limit with eight being normally chosen. The example above can be quantised by the fact that using the LX200 12 inch at F6.3 with an eyepiece under good conditions I can not see the object above other than an averted vision glimpse of the bright cores of the two galaxies in M51. This also applies worse when objects are not overhead as this one can be at the right time in the year so it may take a long time to get quality images of good objects. However time and burning time in a personal interest is what hobbies are all about and anybody would soon lose interest if you had everything with no problems.

So what else can you do with this camera

Here are some more fuzzies in the form of Messier 17 and Messier 20. , Messier 102 The messier 20 image was the most difficult to obtain due to sky location for me but needs stacking as with the M17 image to improve quality.The M102 image is a composite of eight stacked images to get to this level,a bright object even for me,this was taken with a full moon in the sky. More detail in the galaxies outer fringes would have been visible without the moons background light. Yes it is the cats eye nebula taken at prime focus of the LX200. This is all you get without eyepiece projection but the object is very bright and should blow up in size. Finally this is a picture of Hale Bopp Taken 2 days after its discovery. This is a stacked image and shows the power of the LX200 combination due to the fact that it took only minutes to find and image the object.

Planetary imaging

Up till now I have done very little of this with the Cookbook camera mainly due to lack of opportunity but here is a first try at Saturn.

Jupiter is so bright that exposures of only 5 thousandth of a second create a picture on the CCD compared to 100 times this for film. This is the LX200 with an X2 barlow fitted into the special adapter I made for eyepeice projection. This is possible because the Meade barlows dismantle easily to leave the lens element on its own.

Jupiter in Colour is a little more difficult here it is necessary to sort images out of the three colours to get the best for each colour. Combining them after that takes only several minutes to achieve with a little added processing from an editing package such as Paint Shop Pro to tidy up the loose ends. The image was taken using the LX200 with the barlow giving a focal length of six metres.

You have to get used to taking lots of images until you find one that has detail. Atmospheric ripple even at this low magnification scraps most of the images and this is why I am going to have a go at video imaging instead.

last page update 1/9/99 ( Brandon S. Jones)