Lesson #5: Sampling Calculations FR/EN
Here is the summary of this online course available in French and English:
1. General
- Types of sampling
- Atmospheric turbulence
2) Calculations
- Calculation of the apparent field
- Calculation of the resolving power of an optical instrument
- Effective sampling
- Ideal planetary sampling
- Ideal deep-sky sampling
- Calculations of the ideal focal length (useful in choosing a new telescope)
- Calculations of the sampling ratio between the imager and main telescope pair versus guide camera and guide telescope
3) Memo
- Oversampling
- Undersampling
- Ranges of correct sampling
- Effective sampling
- Ideal sampling
- Seeing
- Separating power
- Apparent fields
- Reminders of all useful and necessary mathematical formulas
Buying equipment can be stressful and complex: how can you be sure that your new telescope or refractor will work correctly with your camera or camera? Conversely, will his digital camera work correctly with his optical instrument?
Sampling calculations allow you to verify this before purchasing and much more. Indeed, this allows you, for example, to calculate the ideal focal length based on its imager if you are looking for a new telescope. Conversely, if you want to invest in a new camera, you can calculate the ideal pixel size in order to fully exploit its potential.
Sampling is also essential when guiding. Indeed, many customers are surprised and annoyed by their poor guidance results, an RMS for example well above 1. However, the source of these problems is often poor sampling between the main instrument, the guide scope, the main imager and the guide camera. With this lesson, you will be able to determine if your hardware is compatible or if there is a need to make a correction in order to achieve consistent and satisfactory sampling ratios.
Even if sampling is often feared by the general public because of its deeply mathematical nature, it is a parameter that can and must take into account fluctuations due to turbulence, camera types (color or monochromatic) and depending on the quality of the observation location. Thus, sampling becomes a living and less abstract concept.
Thanks to this lesson, you will be 100% sure of your purchase when placing your order with your preferred retailer.
Do you still have doubts about this lesson? Do you want to ask us any questions? So get in touch with us by writing to us at contact@astrophotographieonline.com!
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Les calculs d'echantillonnage vous permettent de vérifier un certain nombre de paramètre avant l'achat ou avant de planifier sa sortie d'astrophotographie.
Concrètement, l'échantillonnage vous permet par exemple de calculer la focale idéale en fonction de son imageur si vous cherchez un nouveau télescope.
À l'inverse, si vous souhaitez investir dans une nouvelle caméra, vous pourrez calculer la taille idéale des pixels afin d'en exploiter pleinement le potentiel.
L'échantillonnage est également primordial lorsque l'on fait du guidage. En effet, beaucoup de clients s'étonnent et s'énervent de leur mauvais résultats de guidage, un RMS par exemple largement au-dessus de 1. Pourtant, la source de ces problèmes est souvent un mauvais échantillonnage entre l'instrument principal, la lunette de guidage, l'imageur principal et la caméra de guidage.
Avec cette leçon, vous pourrez déterminer si votre matériel est compatible ou s'il y a besoin d'effectuer une correction afin de tomber dans des rapports d'échantillonnage cohérents et satisfaisants.