Gerd Neumann jr.

Development and production of
optical and mechanical Instruments


You are here: Products -> Astronomik filters -> Astronomik IR-Cutoff filter, L-filter and MC-Clear glass
products:
Astronomik IR-Cutoff 1,25"
Art.-Nr.: 10.230.125
Astronomik IR-Cutoff 2"
Art.-Nr.: 10.230.200
Astronomik IR-Cutoff 50mm
Art.-Nr.: 10.230.201
Astronomik IR-Cutoff 38mm
Art.-Nr.: 10.230.340
Astronomik MC-Clear 1,25"
Art.-Nr.: 10.231.125
Astronomik MC-Clear 2"
Art.-Nr.: 10.231.200
Astronomik MC-Clear 50mm
Art.-Nr.: 10.231.201
Astronomik MC-Clear 38mm
Art.-Nr.: 10.231.340
Astronomik L-Filter 1,25"
Art.-Nr.: 10.230.125
Astronomik L-Filter 2"
Art.-Nr.: 10.224.200
AstronomikL-Filter 50mm
Art.-Nr.: 10.224.201
Astronomik L-Filter 38mm
Art.-Nr.: 10.224.340

matching products:
filterwheel FR-03
filter drawer system
adapters

Astronomik IR-Cutoff filter

For the use in front of a CCD- camera we offer you the Astronomik IR- cut off filter. CCD sensors are very sensitive not only in the visual spectral range, but even far into the infrared. On pictures, taken without IR- cut off filter, some objects look totally different, as one knows them from photographs or from visual observation. The IR- radiation produces at all optical systems, where lenses are (also) used for the image (also at eyepiece projection, Barlow- and Shapley- lenses), a more or less big glare around the image of the visual light. You will see this glare also at the best apochromats, if they are not specially calculated for CCD use. The glare will disappear by using an IR- cut off filter in front of the chip.

The Astronomik IR- cut off filter can be used at all focal ratios. It will produce its full performance also at a 1:1.2 photo lens as well as with a 1:20 refractor. Because the glass substrate has a very high optical quality, the use in front of the lens without any loss in the image performance is possible. Due to the extreme robust coats the filter can be used as a protection of sensitive optics.

One word concerning the comparison with other IR- cut off filters: You can get IR- cut off filters from many different manufactures for very different prizes. Please, compare the transmission values and ask for information on the optical quality and about the mechanical capacity. We regularly receive from customers, who made these comparison, the response, that the Astronomik IR- cut off filter is worldwide the best IR- filter.

Astronomik L-Filter

The Astronomik L-Filter is a filter that blocks UV and IR. It has the same transmission as our R+G+B filters and gives you no color-shifting when combining LRGB images. It has also the same thickness than all other Astronomik-CCD filters.

Astronomik MC-Clear

The Astronomik MC-Clear is a multlayer-coated filter with no special optical effect. It has the same thickness as all other Astronomik-CCD filters and gives you the ability to focus your system with all energy entering your telescope.

  • Transmission of more than 97% in the visual range
  • Extrem steep cuttoff at 675nm
  • full H-alpha (656nm) transmission
  • IR- blocking up to 1200nm
  • completly resistant against high humidity and scratches
  • highest optical quality on the market

This filter is available in the following sizes:

mounted filter in 1,25" (31,8mm) cell
mounted filter in 2" (50,8mm) cell
unmounted filters with 38mm diameter (34mm optical)
unmounted filters with 50mm diameter
unmounted filters with custom diameters up to 50mm are available upon request

Impressum: Gerd Neumann (2008)