Transformation Coefficients SeeStar S50

Technology
1

As I try to understand the SeeStar and applicability to photometry, I imaged the Standard Fields M 67 and Melotte 111. I extracted the TG/TB from the FITS files, and plotted the Catalog G/B versus my measured TG/TB:

image
image752×647 40.2 KB

image
image752×647 39.6 KB

It appears that I have good correlation for V vs TG and B vs. TB, however there is more noise in the B/TB data.
Next, from there, I captured the catalog B-V and plotted it against my instrumental TB-TG:
image
image752×662 52.6 KB

Looking at the data, there is an offset between the M 67 and Melotte 111 data, however the slopes of the curves are virtually identical.

My question is “Did I do this right?” and “Does my data look reasonable?”

Thanks

Scott (MDSA)

2

I would suggest following Ken Menzies excellent workflow as described here

I followed this for my Seestar some time ago. I generally found TG very close to V, however TB and TR were generally poor fits for standard B and R.

Regards
Andrew

1 Like
3

Thank you Andrew. I was trying to understand the process and mechanics of determining transformation coefficients before I had VPHOT do it for me. Does the methodology look correct?