Optimal exposure time

What should be captured and how?

Type of object:

Type of camera:

Filter:

Telescope specifications

Telescope aperture:

mm

Telescope focal length:

mm

Obstruction (area-related):

%

Number of mirrors in telescope:

Reflectivity of mirrors:

%

Number of lenses in system:

Transmission of lens surfaces:

%

Camera specifications

Pixel size:

µm

Full Well Capacity:

e^-

Quantum efficiency in [%]
B-band (Peak 436 nm)	V-band (Peak 545 nm)	R-band (Peak 641 nm)	HeII (468,6 nm)	Hβ (486,1 nm)	OIII (500,7 nm)	HeI (587,6 nm)	Hα (656,3 nm)	NII (658,4 nm)	SII (671,7 nm)

Gain:

e^-/ADU

Dark current:

e^-/Pixel/s

Readout noise of camera depending on selected gain:

e^- (RMS)

Filter specifications

Bandwidth narrowband:

nm

Filter transmittance:

%

Notes on filter bandwidth:

Enter one of the filter bandwidths for Duo- or Multi-Narrowband (Ha, Hb, SII or OIII).

Narrowband filters with a color camera are unusual, but feasible.

If filter bandwidth > 4nm, Ha and NII are added together in the Ha value.

Sky properties

Sky brightness:
(https://www.lightpollutionmap.info)

mag/arcsec²

Object specifications

Apparent magnitude in [mag]
B-band	V-band	R-band

Apparent size:

'

Elevation angle above horizon:

°

In which frequency band is the apparent brightness of the object indicated:

Ratio in which the fog emits (sum must equal 1; e.g.: 0 : 0.3 : 0 : 0.5 : 0 : 0.2)
	HeII (468,6 nm)	Hβ (486,1 nm)	OIII (500,7 nm)	HeI (587,6 nm)	Hα (656,3 nm)	NII (658,4 nm)	SII (671,7 nm)
If specified in the B-band				-	-	-	-
If specified in the V-band	-
If specified in the R-band	-	-	-

Available photon flux data:

log(FHβ):
(VizieR or ESO)

mW/m²

Factors of the other emission lines compared with Hβ when Hβ is normalized to 100%
HeII (468,6 nm)	OIII (500,7 nm)	HeI (587,6 nm)	Hα (656,3 nm)	NII (658,4 nm)	SII (671,7 nm)

Photonenfluss in [erg/cm²/s/Å] (Williams)
HeII (468,6 nm)	Hβ (486,1 nm)	OIII (500,7 nm)	HeI (587,6 nm)	Hα (656,3 nm)	NII (658,4 nm)	SII (671,7 nm)
E-13	E-13	E-13	E-13	E-13	E-13	E-13

Observer parameters

Altitude of observer location above sea level:

m

Noise specifications

Accepted noise component in the individual sum images (usually 5%):

%

Gewünschtes Signal-Rausch-Verhältnis (SNR) der einzelnen Summenbilder
Luminance	B-band	V-band	R-band	Color camera (OSC)	HeII	Hβ	OIII	HeI	Ha	NII	SII

Intermediate values

Electron rate by object in [e^-/Pixel/s]
Luminance- filter	B-filter	G-filter	R-filter	Color camera (OSC)	HeII-filter	Hβ-filter	OIII-filter	HeI-filter	Ha-filter	NII-filter	SII-filter
0	0	0	0	0	0	0	0	0	0	0	0

Electron rate through sky glow in [e^-/Pixel/s]
Luminance- filter	B-filter	G-filter	R-filter	Color camera (OSC)	HeII-filter	Hβ-filter	OIII-filter	HeI-filter	Ha-filter	NII-filter	SII-filter
0	0	0	0	0	0	0	0	0	0	0	0

Background limited exposure time in [s]
	Luminance- Filter	B-filter	G-filter	R-filter	Color camera (OSC)	HeII-filter	Hβ-filter	OIII-filter	HeI-filter	Ha-filter	NII-filter	SII-filter
Exposure time	0	0	0	0	0	0	0	0	0	0	0	0
Reduction factor
offset with factor	0	0	0	0	0	0	0	0	0	0	0	0

Reduction factor: Exposure times that are too long occasionally lead to difficulties when guiding,
or very bright planetary nebulae saturate the pixels so that no number of single shots is calculated.

Resulting values

Number of single shots resulting from SNR and background-limited exposure time
Luminance- filter	B-filter	G-filter	R-filter	Color camera (OSC)	HeII-filter	Hβ-filter	OIII-filter	HeI-filter	Ha-filter	NII-filter	SII-filter
0	0	0	0	0	0	0	0	0	0	0	0

Total exposure time
Luminance- filter		B-filter		G-filter		R-filter		Color camera (OSC)		HeII-filter		Hβ-filter		OIII-filter		HeI-filter		Ha-filter		NII-filter		SII-filter
min	h	min	h	min	h	min	h	min	h	min	h	min	h	min	h	min	h	min	h	min	h	min	h
0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0

Full Well Capacity [e^-] exceeded?
Luminance- filter	B-filter	G-filter	R-filter	Color camera (OSC)	HeII-filter	Hβ-filter	OIII-filter	HeI-filter	Ha-filter	NII-filter	SII-filter
0	0	0	0	0	0	0	0	0	0	0	0

Luminance- filter		B-filter		G-filter		R-filter		Color camera (OSC)		HeII-filter		Hβ-filter		OIII-filter		HeI-filter		Ha-filter		NII-filter		SII-filter
min	h	min	h	min	h	min	h	min	h	min	h	min	h	min	h	min	h	min	h	min	h	min	h
0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0

Luminance- filter		B-filter		G-filter		R-filter		Color camera (OSC)		HeII-filter		Hβ-filter		OIII-filter		HeI-filter		Ha-filter		NII-filter		SII-filter
min	h	min	h	min	h	min	h	min	h	min	h	min	h	min	h	min	h	min	h	min	h	min	h
0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0

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Optimal exposure time

Luminance- filter		B-filter		G-filter		R-filter		Color camera (OSC)		HeII-filter		Hβ-filter		OIII-filter		HeI-filter		Ha-filter		NII-filter		SII-filter
min	h	min	h	min	h	min	h	min	h	min	h	min	h	min	h	min	h	min	h	min	h	min	h
0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0