dispersed imager

Putting grating in front of the lens. First order light emerges at an angle given by lambda=d sin(theta).

line density per mm	d (microns)	theta(500 nm), deg	theta(900), deg	theta(1000)	1000-900 (deg)
100	10	2.87	5.16	5.74	0.57
300	3.33	8.62	15.68	17.45	1.79
500	2	14.4	26.74	30.00	3.26
1000	1	30	71.8	90(!)	NA

focal length

horizontal FOV

vertical FOV

900-1000 span (pixels)

filter threads

reasonable combo

50

39.6

27

443*(lpmm/500)

72 mm

500 lpmm gives 443 pixels, gets zeroth and first order

85

23.9

16

754*(lpmm/500)

58 mm

300 lpmm gives 452 pixels, gets zeroth and first order

135

15.2

10

1198*(lpmm/500)

??

300 lpmm gives 720 pixels, misses zeroth and first order

100 lpmm gives 240 pixels, gets zeroth and first order

So we basically want to have FL*lpmm~85*300=25000.