Basic Data
| Maker: | Wm. Harris |
| Date (year): | 1830 (1815-41) |
| Description: | "Wm. Harris & Co. 50 Holborn & at Hamburg" Brass telescope on a table stand |
| Signature: | |
| Collection: | Private Collection |
| Accession #: | A.568 |
| Style: | other |
| Objective type: | triplet |
| Notes: | One 4-lens terrestrial eyepiece and three 2-lens astronomical eyepieces |
Objective Data
| Lens 1 |
Lens 2 |
Lens 3 |
Complete |
| CA curvature (diopters): |
2.845 ± 0.003 |
-3.336 ± 0.003 |
3.134 ± 0.003 |
|
| CB curvature (diopters): |
-3.136 ± 0.003 |
3.336 ± 0.003 |
-2.486 ± 0.003 |
|
| PD lens power (diopters): |
3.019 ± 0.004 |
-3.998 ± 0.004 |
3.022 ± 0.002 |
2.073 |
| fD focal length (mm): |
331.2 ± 0.4 |
-250.1 ± 0.25 |
330.9 ± 0.22 |
499 |
| t thickness (mm): |
6.62 |
2.92 |
5.72 |
|
| d free aperture (mm): |
70 |
70 |
70 |
70 |
| nD refractive index: |
1.5064 ? 0.0008 |
1.5981 ± 0.0007 |
1.5392 ± 0.0005 |
|
| ν Abbe No.: |
58 ± 2 |
39 ± 3 |
56 ± 1.5 |
|
Eyepiece Data
| No. of eyepiece elements: | 4 |
(elements of one eyepiece) |
| Lens 1 |
Lens 2 |
Lens 3 |
Lens 4 |
Complete |
| fD focal length (mm): |
48.3 |
57.6 |
74.4 |
48.2 |
34.5 |
| d diameter (mm): |
19 |
18 |
26 |
22 |
|
| s spacing (mm): |
|
71 |
84 |
71 |
|
| CA curvature (diopters): |
6.456 |
1.763 |
23.8 |
34.6 |
|
| CB curvature (diopters): |
-34.6 |
-26.8 |
-26.7 |
-6.50 |
|
| M magnification: |
|
|
|
|
13.9 |
| FOV field of view (degrees): |
|
|
|
|
7.1 |
Objective Color Curve Data [(Δf/f)x10-3]
| # |
Wavelength (nm) |
Paraxial |
70% Zone |
Whole Lens |
| 1 |
482 |
|
|
0.2 ± 0.6 |
| 2 |
575 |
|
|
0.0 |
| 3 |
652 |
|
|
0.3 ± 0.3 |
Attached Files (click to enlarge)
This entry, number 39, was created on 2006-08-09 21:26:01 and last modified on 2007-02-19 15:51:19.
