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The Patent Pending DG Spectrum 401 Page

Our DG Spectral Filters Cost Four Times (4x) LESS Than what Competitors Charge per stellar magnitude, and at Spectral Optics, if you already have a Telescope, a CCD Camera and its control software, You can get Our Entire Package with Everything You Need to Produce Professional Level Spectral Images the First Night Out and ALL for LESS than the Cost of an Eyepiece!

Why is this called Spectrum Catching 401?

Because everybody else only tells you about the basic stuff - course level 101. Here, you will learn how to do it like the pros do for only the cost of a cheap filter. If you are like I was this will be like a Taking Spectrum Pictures for Dummies course.

Step One: You will need some type of Telescope. Do you have that one covered?

Step Two: You will need an inexpensive CCD camera that you can connect to your telescope. It needs to be extremely simple to operate like Meade's new LPI camera that they are giving away with most of their new telescopes (its $150 otherwise). The software that comes with this camera is almost fool proof. With it you can take really beautiful pictures the very first night out (but you're pictures will get a lot better with a little more experience). There is a Great LPI Forum on Yahoo with thousands of LPI users that you can join for free and see some of the Great pictures they are taking with it.

Step Three: You will need some type of Spectrum catching filter or device. It will have to easily work with your telescope, CCD camera and software and be able to produce pictures similar to the ones shown above, with your equipment. The DG Spectrum Filter is just such a device and prices start at under $100 USD. There is a line of them especially made just for the Meade LPI camera so neither compatibility nor price should be an issue.

There are a number of different manufacturers that sell spectrum attachments for telescopes. Their prices range from several hundred dollars to thousands of dollars. While most of these devices will function in some way with most telescopes and CCD cameras they are marginal at best when they are not used in the way they were designed for. This is because most of these devices were designed for visual observation alone or for a specific commercial grade telescope and specific camera system. Neither of these avenues lends itself well for amateur CCD photography.

Poor results are seen when one of these spectrum devices is not used for the purpose it was designed. Most spectrum devices costing from $200 to $1500 were designed for visual observations. If you have any kind of spectrum catching devices and you paid less than $1500 USD then you probably have one of these visual devices.

An example of how using a spectrum catching device in a manner it wasn't designed for is seen in these two photographs (the one on the left and the one on the right). This is a spectrum catching device that was designed to be mounted close to a CCD chip, but instead was mounted on the filter screws at the end of the camera's lens housing. This arrangement put more distance between the device and the CCD chip then the device was designed for. This causes the spectrum to be excessively wide and consequently very dim.

The picture to the left is the left half of the spectrum and the picture to the right is the right half of the spectral image. Spica's spectrum image is almost twice the width of the CCD chip so two pictures need to be taken to show the entire spectrum. As the spectrum is spread out so much it is also very dim.

This can all be avoided if you select the right device for your needs at the very start. See the two examples below.

The image to the left is the same star Spica whose spectrum is shown in the two pictures just above. The picture to the right is a dimmer star named Chort. Both of these pictures show not only the star itself but its spectrum as well. All of these spectrums are called line spectrums as the spectrum is a straight line and not expanded vertically as is customarily seen in professional spectrum photographs.

The reason we showed the spectrum, in these last two pictures, this way is that this is generally the way amateur spectrum pictures initially look. Some amateurs use ingenious techniques to expand the spectrum vertically so the spectral lines can be seen. One of the easiest methods is to just cut off the clock drive on the telescope mount and let the image drift for a few seconds. However, this is not recommended as the image can lose information very quickly this way. Another reason not to do this is because VSpec isn't set up to handle anything but a straight line image.

However, this is getting off of the track. Suffice it to say that we will learn in the image processing section how to see the spectral lines, and this process is extremely simple and fast. The picture to the right is one where the spectrum is stretched so the spectral lines can be seen. It is the same star Chort that is shown in the above right line spectrum picture.

Lesson One - Most of the screw-in filter spectrum devices don't work very well with the less expensive line of CCD cameras. Be sure you buy a spectrum device that is designed to work with your equipment.

Step Four: You will need some sort of a computer access for your CCD camera so you can take pictures, unless you are going to do this using a time exposure film camera. This discussion will assume that you are using a CCD camera.

That's all the equipment you will need. Next, we will discuss a very simple system and show you what you can do with it the first night out.

Step Five: The First Night Out.

A very simple CCD camera is made by Meade's for use on any telescope having a 1.25" (or 0.965" eyepiece holder). This is their LPI camera. It also comes with all the software reqired to control it, so there is nothing else to buy to get it to work. It is a very small camera that has a 1.25" nose piece that slips down into any 1.25" eyepiece holder (like the focus tube on your telescope).

There is a single USB cable that connects to the camera and the other end of this cable connects to the USB ort on your computer. If you have an older computer that doesn't have a USB port then you can buy a serial to USB adapter at most computer or electronic stores for under $20.

The Type A and Type B Compact Spectrum DG Filters were designed to mate with the Meade LPI camera. A Meade LPI camera equipped with a Type A Compact Spectrum DG Filter was used to make the last three spectrum photographs shown above.

Now that you have telescope, a CCD camera, a Spectrum catching device, software, a computer and a USB cable you are ready to start.

Step Six: Taking your pictures.

1. After you have everything setup and have selected an object you need to center it in your eyepiece. You should use an eyepiece with a focal length of 10 mm to 18 mm. Center the object in the eyepiece and then take the eyepiece out of the telescope.

2. Take the cover cap off of the LPI camera and insert the DG Filter. Align the white notch on the DG Filter with the top of the camera. This way the spectrum will be shown along the horizontal axis which is the longer side of the CCD chip.

3. Put the LPI camera (with the DG Filter attached to it) in the telescope's eyepiece holder.

4. Connect the cable from the LPI camera to the computer's port (USB or Serial whichever you have arranged for).

5. Start up the computer. Then start up Meade's AutoStar Suite. Then select Image and select LPI Imaging from the drop down menu.

6. If you have centered the object properly, and its not too dim, it will show up on the LPI monitor screen. Using your mount controls slowly move the object close to the left side of the LPI monitor screen. This will allow both the object and its spectrum to be seen at the same time on the screen.

7. You probably won't see the spectrum at first if the exposure is set to produce a good image of your object. In order to see its spectrum you will need to increase the exposure time until your object looks too bright. For Jupiter set the exposure to 0.100 seconds and you should see its spectrum. If you have a second magnitude star, like Denebola, or brighter then a one second exposure should show its spectrum very well.

8. At the very top of the LPI control panel there is a tab. One is marked Take Pictures, and the other is marked Settings. Select the Settings tab and enter the directory where you want the pictures that you take stored - Image Directory. You won't be manually using the Dark frame images so you can leave the default path for them alone (or you can change it if you like). But after you are finished taking pictures you will need to know where your images are stored as you will need to process them.

9. Then place a cover over the front of the telescope and go to the computer and select Object - Take Darks. I would take a full set of dark frames from 0.001 to 16 seconds. This will take a little under 15 minutes. Its extremely important to have a set of dark frames taken at the very same temperature that you are taking pictures at. After the dark frames are finished uncover the telescope.

10. Then go to the LPI control console and click Dark Sub in the upper left corner (this will automatically subtract out the dark frame from each picture automatically). Then select Track and Combine in the upper middle section (you want them both checked). Then go to the Object box and select Deep Sky.

11. Take the cursor and make a small box around your object. When you release the cursor a yellow box will cross the object. This means that the software will align everything in all of the pictures using this object as reference. Then make sure the exposure is adjusted so that the spectrum looks good then select Start and the software will start taking pictures and stacking them all automatically. You need to take at least half a dozen pictures (more if possible) to get rid of most of the electronic noise.

12. While the camera is taking pictures the composite picture will be seen on the monitor. When it looks good click Stop (in the upper right corner where the Start button was) and you are all finished.

Step Seven: Processing your pictures.

We use Adobe's PhotoShop 7 to process our pictures but you can use whatever you might have. If you don't have any image processing software you can still look at your pictures without doing anything else. Processing will bring out a lot of the hidden detail in the image. All professional astronomical images have been processed by the time you see them.

To bring out the details in the spectrum we only use a few of the functions available in PhotoShop. One is the Unsharp Mask (it is used to bring up the color in the spectrum), another is Levels (it is used to set the image background to black, and then to bring up the white level so the spectrum looks good and bright). While Unsharp Mask and some form of the Levels function is available in most good astronomical image processing software the other special functions needs to bring out and display the spectral detail is not available in these packages.

PhotoShop 7 is no longer the current version but it is the last version that didn't require activation. Copies of PhotoShop 7 are still being sold on ebay for around $100. This is extremely well suited for our specific use. It offers features that are not found in the special, and generally expensive, astronomical image processing software available today.

Photo Deluxe 4 is also made by Adobe and as PhotoShop 7 it is no longer being made. However, copies of it are still being sold on ebay for under $50. This image processing software has all of the PhotoShop 7 features that we need. These features, in some cases, have different names between these two Adobe applications, but there are all there.

The big inconvenience with Photo Deluxe 4 is that it will only save images in Adobe's proprietary formats (while it will import a JPG file it won't save in that format). The work around for this is to process the image and then do a screen print (which copies the processed image to the clip board) then go into the image processing software included on our CD and paste it into a new image and then just save it as a JPG or whatever.

If you don't have any image processing software or don't want to spend the money to purchase PhotoShop don't despair, for included on our CD is a full featured astronomical image processing software package. While the included package doesn't have all of the rich features available in PhotoShop there are work arounds that will allow you to accomplish the same thing, just in a different way. For example: If you have PhotoShop 7 then you won't need to use any of the special image processing software included on the CD. If you don't have PhotoShop then you can use the two special image software packages included on our CD.

Additionally, even if you do have PhotoShop you can still use the two special software packages included on our CD to view the spectral characteristics in yet another manner. We have seen to it that no matter what software you have, or do not have, available you will still be able to process your spectral images as long as you have a Windows compatible computer.

The actual process that we use is a proprietary process that we developed and refined over time and we have a special UCC Copyrighted on it. This process is set out in full detail in the step by step training document included on our CD that accompanies all purchases of our DG Filters.

To illustrate the results of our proprietary process we photographed a number of different types of stars using a Type A1 - DG Filter on a LPI camera. Then each photograph was processed and then all of the images were arranged and indexed by their zero order image and the star's spectral type. The results are shown in the above very tall picture. Click on the picture to see the full resolution image.