- Messages
- 3,696
- Name
- Frank
- Edit My Images
- Yes
Over the last month or so I've read several references to using the Astronomik CLS clip filter. This is designed to block the bit of the electromagnetic spectrum that includes that horrid orange-yellow glow that plagues anybody trying to photograph the stars. Miine cost £110 from Rother Valley Optics.
The cool bit about this filter is that it doesn't go in front of the lens, but between the lens and the sensor. It takes advantage of the extra space available there in APS-C cameras, which results in two limitations - a) it will only work with cameras that can use EF-S lenses and, b) it won't work with EF-S lenses.
That last restriction will be a major pain for people who like to use the Canon 10-22 or 18-55 for wide-field and startrail shots. But other lenses are usable and are probably better.
But does it work? Well, the reason I bought it because the view from my garden has Horsham, Crawley and Gatwick all polluting the skies. Here's a 30s exposure at ISO1600, f2.8, 11mm.
Pretty bad, huh!
Here's what happens with the filter on...
OK! I'm quite impressed. It does block quite a bit of light, so the image with the filter has been boosted by 1 stop. The filter also makes everything look blue. Using a grey-card allows one to set a custom white-balance in Lightroom which gives the following...
I think I prefer the original.
Now I've got no excuse at all to avoid getting a tracking mount of some sort so I can take some really long exposures with longer lenses.
The cool bit about this filter is that it doesn't go in front of the lens, but between the lens and the sensor. It takes advantage of the extra space available there in APS-C cameras, which results in two limitations - a) it will only work with cameras that can use EF-S lenses and, b) it won't work with EF-S lenses.
That last restriction will be a major pain for people who like to use the Canon 10-22 or 18-55 for wide-field and startrail shots. But other lenses are usable and are probably better.
But does it work? Well, the reason I bought it because the view from my garden has Horsham, Crawley and Gatwick all polluting the skies. Here's a 30s exposure at ISO1600, f2.8, 11mm.
Pretty bad, huh!
Here's what happens with the filter on...
OK! I'm quite impressed. It does block quite a bit of light, so the image with the filter has been boosted by 1 stop. The filter also makes everything look blue. Using a grey-card allows one to set a custom white-balance in Lightroom which gives the following...
I think I prefer the original.
Now I've got no excuse at all to avoid getting a tracking mount of some sort so I can take some really long exposures with longer lenses.
