In recent years, dSLR cameras have been used extensively in astrophotography and the EOS range of digital SLR cameras from Canon have been shown to give impressive results. The only real draw back has been that the fitted filter cuts a large amount of the red light at particular frequencies, giving a very poor response in the crucial Hydrogen Alpha band of emission nebulae.

Astronomiser offer a service to replace the standard IR blocking and antialiasing filter fitted to your Canon Camera with a Baader filter which still blocks out all of the IR and UV bands but with a much steeper cut-off which allows over 90% transmission across the whole of the visible range.

For dual filter cameras, a filter removal may be more appropriate see this page for a comparison between the two operations.

A note on the use of EOS Clip filters

Recently, a myth has grown up around the use of EOS clip filters stating that removing the rear filter and replacing it by using a clip filter in front of the mirror will compensate for the change in the optical path allowing sharp focus to be maintained. This is *not accurate* - please read this very short explaination to see why.

Astronomiser has years of experience in modifying dSLR cameras with hundreds of cameras modified successfully. We also supply control cables and other products for use with your dSLR. With us, your camera is in safe hands.

Do not forget - our price includes return postage so all you pay is the price quoted below to benefit from our experience and knowledge in both astro-imaging and modifying all types of dSLR cameras.

The first two sections below apply to the filter change only.

Baader #245 9211 filter transmission curve

Restoring Normal Use, post mod

Filter change vs filter removal

Software

Cost

Book and pay for your camera to be modded

Baader BCF Filter transmission Curve...

Baader filter transmission compared to original Canon 40D filter...

Restoring Normal Use, post mod...

Pre mod...

Post mod...

After the filter change, if you wish to use the camera normally, you may wish to use an astronomik OWB clip filter available from Modern Astronomy - these only work with EF lenses (not EF-S) other filters are also available.

It is possible to use a simple auto levels adjustment in your photo processing software, i.e., PhotoShop.

Another alternative is to use a 'Custom White Balance'. To do this you should follow these steps:

• In auto, take a shot of a piece of white paper from around 2 or 3 feet away.
• Put the camera in manual mode.
• Open the menu and in settings choose Custom WB.
• Select the image you have just shot.
• In the settings menu, set the white balance to custom.
• After this point, any shots taken in Manual mode (non-RAW) will use the values obtained from this image to adjust white balance.

NOTE: When shooting in manual mode most settings are automatic unless changed - remember to activate the flash when appropriate.

Filter change vs filter removal...

The replacement filter is the same thickness as the removed filter so auto-focus will still operate correctly after the filter is replaced and the camera can still be used for normal photography, but if you intend to use the camera exclusively for astronomy, then this isn't an issue.

If you add or remove any amount of glass between a lens and the sensor then the auto focus will not operate correctly.

Refractors - even the best apo-chromatic refractors - do not bring IR and UV to focus at the same point as visible light so another advantage of the filter change is that IR and UV are still blocked with a very sharp cut off into the visible light region and therefore stars won't be blobby and bloated by out of focus UV and IR light. If you use the camera exclusively with a newtonian (without reducers etc) then this won't be a problem, but if you go for filter removal only and use the camera with a refractor then you will also need a UV/IR blocking filter.

astronomiser always recommends that you have your filter replaced to protect the surface of the sensor - although it can be expensive to replaced a damaged filter, it is far more expensive to replace a damaged sensor.

Software...

To use your canon camera for Astrophotography you can either just attach it to the back of a scope and use it in manual mode (with a remote) or use software. Astronomiser recommends Astro Photography Tool from www.astroplace.net. Other software such as DSLR Shutter, DSLR Focus, MaxDSLR (from Diffraction Limited, the makers of MaxIm DL), ImagesPlus and DSLR Control can also be used with the use a serial control cable - see Canon Camera Control.

This type of software allows you to set exposures for a whole imaging session, i.e., set number of exposures, timings, ISO, image type etc.

Cost...

The cost of this service includes return Special Delivery postage. The normal turn-around time will be 7 days within the UK unless otherwise stated at time of ordering. This service can now be booked online by simply clicking one of the below buttons, making a secure credit card payment through the Paypal web cart system (no PayPal account required) and then send your camera body only (no lens, battery or CF Card is required) to:

Please ensure that the camera is well packed with plenty of padding (i.e., bubble wrap) and insure the camera for it's full replacement value. In the UK, I recommend Special delivery, internationally, an expedited signed for, insured postal service is essential to guarantee your camera's safety.

To book the service without using the Paypal web cart service, you can write to me - contact_at_astronomiser_dot_co_dot_uk (replace anti-spam _at_ with @ and _dot_ with a full stop), use the Contact Page or call me on 07709490738. Using these methods, I can accept payment by cheque/ PO or PayPal.

Book and pay for your camera to be modded...

Guarantees.

The work will be guaranteed for 3 months after time of delivery against all defects of workmanship - this guarantee is separate from any guarantees you may already have on the camera, and the work carried out will void your canon guarantee.

If your camera is less than one year old then astronomiser's guarantee is extended to cover all parts and labour for any fault that develops in the camera after modding for three months.

Any damage which occurs during the filter replacement procedure will be communicated to the customer immediately. Although it may slightly add to the expected delivery time, the camera will be returned in the same condition as supplied or better with the filter change carried out.