The following table has been taken partly from the original NIRC2 proposal by Keith Matthews and Tom Soifer, and partly from information on the as-built instrument.

The original detector electronics based on inMOS transputers was replaced with an STA Archon controller in 2023, but the detector is still the original Aladdin III InSb 1024x1024 array. Science operations with the Archon controller started on Nov 20, 2023. The table below includes detector electronics performance provided for both, transputers and Archon.

Input f/ ratio f/15

Wavelength range 0.9-5.3 microns

Field of view

Narrow camera: 10x10 arcsec

Medium camera: 20x20 arcsec

Wide camera: 40x40 arcsec

Pixel scale

Narrow camera: 0.009942 arcsec/pixel (+/- 0.00005")

Medium camera: 0.019829 arcsec/pixel

Wide camera: 0.039686 arcsec/pixel

Filters z, Y, J, H, K, Ks, Kp, Lw, Lp, Ms, HeI, Pa_gamma, Jcont, Pa_beta, H_cont, CH4S, H2, Fe II, CH4L, Br_gamma, Kcont, CO, H2O, PAH, Br_alpha, Br_alpha_cont

Pupil masks

1 circular fixed, circumscribes the telescope pupil.

1 hexagonal fixed, inscribes the telescope pupil and masks spiders. Needs to be used in vertical angle mode, i.e. telescope following pupil.

1 circular rotating, inscribes the telescope pupil and masks the spiders.

3 hexagonal, rotating.

Slits Slit widths: 10, 20, 30, 40, 60, 80, 120, and 160 milliarcsec

Coronagraphy

Circular Lyot stops: 100, 150, 200, 300, 400, 600, 800, 1000, 1500, 2000 milliarcsec

Vortex coronagraphs: L/M-band optimized (vortexlm), K-band optimized (vortexk)

Grisms

Low resolution (lowres): Resolving power per pixel in K with the narrow camera: 10,200

Medium resolution (medres): Resolving power per pixel in K with the narrow camera: 17,300

Detector

1024x1024 InSb Aladdin-III array, 27 micron pixels

32 simultaneous outputs, grouped in 8 pixels across a row in each of 4 quadrants

Subarray capability down to 32x120 pix

Nominal operating temperature: 29 K

Gain:

Prior to Nov 20, 2023 (transputers): 4 e^-/DN

Nov 20, 2023 and after (Archon): 8 e^-/DN

Detector readout modes

Single (sampmode 1): Single read. Used for engineering purposes.

CDS (sampmode 2): Correlated Double Sampling. One read pair. Normally used for bright targets and/or high background conditions that require the minimum integration time for a give sub-array size.

MCDS (sampmode 3 N): Multiple Correlated Double Sampling. Multiple read pairs (N is the number of read pairs). Used for faint targets and/or low background conditions. The readnoise decreases approximately as 1 over the square root of the number of read pairs.

UTR (sampmode 4 N): Sampling Up The Ramp. Experimental mode available with the Archon controller after November 20, 2023. N is the number of samples up the ramp.

Minimum frame time

Prior to Nov 20, 2023 (transputers): 0.182 sec, full frame in CDS mode

Nov 20, 2023 and after (Archon): 0.170 sec, full frame in CDS mode

Read noise

Prior to Nov 20, 2023 (transputers):

CDS (sampmode 2): ~45 – 50 e^-

MCDS with 16 read pairs (sampmode 3 16): ~15 e^-

Nov 20, 2023 and after (Archon):

CDS (sampmode 2): ~45 – 50 e^-

MCDS with 16 read pairs (sampmode 3 16): ~15 e^-

Dark current < 0.1 electrons/pixel/sec

QE 80% at 1.7 microns

Well depth

Prior to Nov 20, 2023 (transputers): ~9,000 DN at ~1% linearity

Nov 20, 2023 and after (Archon): ~4,500 DN at ~1% linearity

Input f/ ratio	f/15
Wavelength range	0.9-5.3 microns
Field of view	Narrow camera: 10x10 arcsec Medium camera: 20x20 arcsec Wide camera: 40x40 arcsec
Pixel scale	Narrow camera: 0.009942 arcsec/pixel (+/- 0.00005") Medium camera: 0.019829 arcsec/pixel Wide camera: 0.039686 arcsec/pixel
Filters	z, Y, J, H, K, Ks, Kp, Lw, Lp, Ms, HeI, Pa_gamma, Jcont, Pa_beta, H_cont, CH4S, H2, Fe II, CH4L, Br_gamma, Kcont, CO, H2O, PAH, Br_alpha, Br_alpha_cont
Pupil masks	1 circular fixed, circumscribes the telescope pupil. 1 hexagonal fixed, inscribes the telescope pupil and masks spiders. Needs to be used in vertical angle mode, i.e. telescope following pupil. 1 circular rotating, inscribes the telescope pupil and masks the spiders. 3 hexagonal, rotating.
Slits	Slit widths: 10, 20, 30, 40, 60, 80, 120, and 160 milliarcsec
Coronagraphy	Circular Lyot stops: 100, 150, 200, 300, 400, 600, 800, 1000, 1500, 2000 milliarcsec Vortex coronagraphs: L/M-band optimized (`vortexlm`), K-band optimized (`vortexk`)
Grisms	Low resolution (`lowres`): Resolving power per pixel in K with the narrow camera: 10,200 Medium resolution (`medres`): Resolving power per pixel in K with the narrow camera: 17,300
Detector	1024x1024 InSb Aladdin-III array, 27 micron pixels 32 simultaneous outputs, grouped in 8 pixels across a row in each of 4 quadrants Subarray capability down to 32x120 pix Nominal operating temperature: 29 K Gain: Prior to Nov 20, 2023 (transputers): 4 e^-/DN Nov 20, 2023 and after (Archon): 8 e^-/DN
Detector readout modes	Single (`sampmode 1`): Single read. Used for engineering purposes. CDS (`sampmode 2`): Correlated Double Sampling. One read pair. Normally used for bright targets and/or high background conditions that require the minimum integration time for a give sub-array size. MCDS (`sampmode 3 N`): Multiple Correlated Double Sampling. Multiple read pairs (`N` is the number of read pairs). Used for faint targets and/or low background conditions. The readnoise decreases approximately as 1 over the square root of the number of read pairs. UTR (`sampmode 4 N`): Sampling Up The Ramp. Experimental mode available with the Archon controller after November 20, 2023. `N` is the number of samples up the ramp.
Minimum frame time	Prior to Nov 20, 2023 (transputers): 0.182 sec, full frame in CDS mode Nov 20, 2023 and after (Archon): 0.170 sec, full frame in CDS mode
Read noise	Prior to Nov 20, 2023 (transputers): CDS (`sampmode 2`): ~45 – 50 e^- MCDS with 16 read pairs (`sampmode 3 16`): ~15 e^- Nov 20, 2023 and after (Archon): CDS (`sampmode 2`): ~45 – 50 e^- MCDS with 16 read pairs (`sampmode 3 16`): ~15 e^-
Dark current	< 0.1 electrons/pixel/sec
QE	80% at 1.7 microns
Well depth	Prior to Nov 20, 2023 (transputers): ~9,000 DN at ~1% linearity Nov 20, 2023 and after (Archon): ~4,500 DN at ~1% linearity