Color calibration before crop

Software Siril
1

Hello, my name is Manu and I am from Jaén, Spain.

I have a question when it comes to using photometric color calibration.

If we have previously cropped the image, when entering the lens focal length (in my case I use an aps-c reflex camera and a 150-600), does this focal change? pixel size too?

For example, if I shoot at 600mm, in aps-c it becomes 920mm. Do I always have to enter 960 or when cropping that focal length will it be affected? If so, how can we know the correct focal length?

Thanks.

2

No, it doesn’t change. Focal Length and pixel size are used to compute the image escale and this is independent of the “crop” (sensor size / field size).

SiriL is expecting you introduce the real focal length (600mm in your example)

1 Like
3

Thank you very much, Rafa.