optics-Sept-4

A montage of a full range (10mm) focus sweep- focus 0 is at bottom left, focus 9500 is at top right. Each image along a row has a focus +500 from the one before it.

To be concrete, the images in the left most column have, starting from the bottom, foci of 0, 2000, 4000, 6000, 8000 microns.

There is astigmatism in rows 1 and 3. Row 4 has he best focus (row=3, col = 2 and 4500 is the best), but in best focus the images are donuts!

CCD 1, at rows 2210:2500, cols 1510:1900

CCD 2 at rows 1900:2190, cols 1310:1700

Notice that at focus 4000 (on CCD2) there are decent stars on the donut:

Data- the optics sweep:

The optics package:

23:07 1210-1214 bias fine

23:15 1215-1217 g flat 15 secs

23:20 1218-1220 r flat 20 secs

23:26 1221-1223 i flat 25 secs

23:30 1224-1226 z flat 15 secs

23:36 1227-1229 y flat 25 secs

1:00 1244-1264 g 10sec focus= 0 to 10,000 in steps of 500

2:00 1265-1275 g 10sec focus = 4000 to 5000 in steps of 100

2:22 1277-1279 g 10sec focus = 3500, 4500, 5000

2:26 1280-1282 r 10sec focus = 3500, 4500, 5000

2:30 1283-1285 i 10sec focus = 3500, 4500, 5000

2:33 1286-1288 z 10sec focus = 3500, 4500, 5000

2:36 1289-1291 y 10sec focus = 3500, 4500, 5000