>>>>> "Zlatan" == Zlatan Tsvetanov <zlatan@jhufos.pha.jhu.edu> writes: Zlatan> Hi, Getting redshifted P-alpha filters for GRIM2 is, of Zlatan> course, quite interesting and useful. However, having a Zlatan> few fixed wavelength filters would cover only a limited Zlatan> redshift range. I suggest we entertain the idea of having Zlatan> a CVF (circularly variable filter) to cover a much larger Zlatan> wavelength range. This could be used for narrow-band Zlatan> imagig in other lines as well. In weighing these options (CVF vs. filters), it should be remembered that installing a CVF will be more challenging. Perhaps the most fundamental issue is whether adequate spectral resolution can be attained. GRIM II's pupil diameter is on the order of ~25mm and it is in a fairly crowded part of the instrument. Does anyone have any idea how much spectral resolution is achievable with a CVF using a ~25mm spot size? Cheers, Bernie Rauscher APO APO APO APO APO Apache Point Observatory 3.5m APO APO APO APO APO This is message 32 in the apo35-grim archive. You can find APO the archive on http://www.astro.princeton.edu/APO/apo35-grim/INDEX.html APO To join/leave the list, send mail to apo35-request@astro.princeton.edu APO To post a message, mail it to apo35-grim@astro.princeton.edu APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO