Optical Filters
TNG offers a wide set of wide and narrow band filters for imaging purposes that can be used both on OIG and DOLORES. Both instruments are normally equipped with the standard broad-band set, for color equations please refer to the main page of each instrument.
Special and narrow band filters are normally not mounted and not offered in queuing/service observing mode. Visiting astronomers who need using them should send an e-mail to filters staff at least 15 days before their first scheduled night specifying the chosen filter number(s) and instrument(s).
Private filters can also be accomodated in OIG or DOLORES. However, their use must be scientifically justified in the proposal and explicitely endorsed by the time allocation committee. Succesful proposers must provide their filters already mounted on a holder of diameter of 106.0 ± 0.2 mm and thickness less than 10.0 mm. For further information plase contact Adriano Ghedina.
Below please find plots and tables summarizing the main filter parameters. More information, including numerical files with efficiency values, can be obtained by clicking on the filter number in the tables.
Standard broad band filters
| TNG filter # |
Name | Centr. WL. (nm) | FWHM (nm) | Peak Tr. (%) | Normally mounted on |
|---|---|---|---|---|---|
| 01 | U | 361 | 60 | 67 | DOLORES |
| 02 | B | 436 | 103 | 67 | OIG |
| 03 | V | 533 | 93 | 84 | OIG |
| 04 | R | 625 | 128 | 82 | OIG |
| 09 | U | 371 | 42 | 54 | OIG |
| 10 | B | 431 | 102 | 68 | DOLORES |
| 11 | V | 527 | 98 | 82 | DOLORES |
| 12 | R | 644 | 148 | 85 | DOLORES |
| 13 | I | Cut-on 720 | 97 | DOLORES | |
| 29 | u' SDSS | 349 | 68 | 79 | DOLORES |
| 30 | g' SDSS | 478 | 148 | 92 | DOLORES |
| 31 | r' SDSS | 620 | 128 | 94 | DOLORES |
| 32 | i' SDSS | 769 | 145 | 96 | DOLORES |
| 33 | z' SDSS | Cut-on 828 | 97 | DOLORES | |
| 34 | u' SDSS | 349 | 68 | 79 | OIG |
| 35 | g' SDSS | 478 | 148 | 92 | OIG |
| 36 | r' SDSS | 620 | 128 | 94 | OIG |
| 37 | i' SDSS | 769 | 145 | 96 | OIG |
| 38 | z' SDSS | Cut-on 828 | 97 | OIG | |
Special broad and intermediate band filters
| TNG filter # | Filter | Centr. WL. (nm) | FWHM (nm) | Peak Tr. (%) |
|---|---|---|---|---|
| 06 | r | 659 | 81 | 86 |
| 07 | i_OAB | 821 | 214 | 96 |
| 14 | g_OAB | 520 | 88 | 82 |
| 15 | r_OAB | 663 | 110 | 73 |
| 16 | z_OAB | Cut-on 850 | 92 | |
| 27 | TiO_OAR | 769 | 31 | 96 |
| 28 | CN_OAR | 809 | 26 | 96 |
Narrow band filters
| TNG filter # | Name | Centr. WL. (nm) | FWHM (nm) | Peak Tr. (%) |
|---|---|---|---|---|
| 17 | A7385 | 373.5 | 6.0 | 35.6 |
| 18 | A7386 | 378.9 | 6.4 | 42.4 |
| 19 | A7387 | 486.2 | 5.7 | 76.7 |
| 20 | A7388 | 501.2 | 5.2 | 79.1 |
| 21 | A7389 | 509.0 | 5.4 | 81.1 |
| 22 | A7390 | 657.5 | 6.1 | 83.4 |
| 23 | A7391 | 658.8 | 3.2 | 76.8 |
| 24 | A7392 | 665.8 | 5.7 | 87.4 |
| 25 | A7393 | 672.4 | 5.7 | 85.1 |
| 26 | A7394 | 683.3 | 6.1 | 88.1 |
Speckle Camera filters
Please refer to the
Speckle Camera
page.