Astronomik CLS-CCD EOS XT Clip Filter
The Astronomik CLS-CCD XT Clip-Filter EOS APS-C is a tried and true example of an imaging filter, and the new XT variant provides an exceptional level of clarity.
The Astronomik XT filters are an upgraded and improved variant of the Astronomik EOS Clip Filters, using vastly thinner glass to achieve a greater level of clarity and quality. These splendid filters grant incredible potential for aberration-free wide field imaging, the entire image crisp and clear to the absolute edge of the field. This, in particular, is a CLS-CCD filter, filtering out light pollution and enhancing the contrast between various targets. A good filter for DSLR-, CCD- and film b/w-photography as well as observation of deep-sky-objects with telescopes or photo lenses of all aperture f/3 and above.
OPT Product Number: AK-8H00KF
- Ref: AK-CLSCCD-XT Clip Filter
Works well with a modified DSLR - for both widefield and DSO
I recently modified a Canon DSLR (APS-C) to admit the full spectrum of light wavelengths (from upper frequency IR through visible up to lower UV). I mounted the camera on a 80mm APO, where I normally put the guide scope, and attached the guide camera to the APO’s focuser. This allowed me to get 30 minute RAW widefield exposures of the Milky Way without star trails. Even from a fairly dark site with no moon in the middle of the desert, 30 minute exposures can be washed out. This filter worked pretty well. When the shots come out of the camera, the sky is dark with a green Milky Way and whitish-green pinpoint stars, but resetting the white point (using Canon’s Digital Photo Professional free software) results in natural coloring, with a good deal of red, and good contrast between the bright and dark bands of the Milky Way. I had the gain at 100 ISO, and the light frames are not bad by themselves, but still have some dark noise, so shooting a handful of dark frames is a good idea for longer exposures (and you needn’t leave the camera on the scope for that). I also shot some deep space objects in the Antares region with 5 minute subframes. They aren’t bad. I would recommend this filter if you have a full-spectrum modified DSLR, and are not ready to sink $1500 or more in a cooled OSC astronomical camera. If you’re patient enough to shoot darks throughout the night, it is a good trade-off with reasonably good results, and much less expensive than a cooled OSC camera with an APS-C sized sensor.