Hi

I have read the instructions for the Peak to Peak Maximum Allowable Error and its says to use 75% of the scale that I'm imaging at. My guider camera is 6.0" and my main camera is 1.26". What one do I enter in the peak to peak, guider or main camera scale?

-Paul

Hi Paul,

Use 75% of the main camera image scale (about 0.9 arcsec for you). This is because the error you really want to limit is the one in the image acquired by the main CCD, regardless of what the autoguider is doing.

Regards,

-Paul

Hi Paul

Thanks for the quick response. I'm now confused as why we need to enter the correct guider image scale as this value does not seem to change the Min/Max Move values if I raise or lower the guider image scale value. I can see that it changes the pixel values below the min/max read out. Do I need to know those values for something else?

-Paul

I assume the autoguider image scale is needed to update the charts shown below the calculator demonstrating the min/max move of the guide star.

Peak-to-peak allowable error is entered in arcseconds, so it's irrelevant whether it's an error on the guide chip or the imaging chip (the result is exactly the same).

The 75% of image scale suggestion refers to the image scale of the imaging chip, since you are looking to limit the error at the final image scale, not at the guider.

Regards,

-Paul