iTelescope.Net Supported Exposure times are 60, 120, 180, and 300 seconds on our internally or externally guided systems (Some systems, like T13, will support up to 600s on specific targets, but we suggest a maximum of 300s). This includes T3, T5, T14, and T20 in New Mexico; T7, T16 and T18 in Spain; and T8, T9, T12, T13, and T17 in Australia.
For our unguided systems (Using Planewave Ascension 200HR Mounts) supported exposure times are 60, 120, 180, 300, and 600 seconds. This includes T11 and T21 in New Mexico; T24 in California; and T30, T31, and T32 in Australia.
T27 in New Mexico uses a Planewave Alt-Az Fork Mount that will also support 60, 120, 180, 300, and 600 seconds exposure times.
*Supported means we will have the proper calibration files for the listed exposure times as well as the times that the system is physically capable of maintaining proper guiding at. Any unsupported times (especially exposures longer than 600 seconds) will have a much higher chance of poor guiding and poor quality images.
Optimal Exposures depend on your target, filters and telescope you are using. For luminance filters we suggest from 120 to 300 seconds per sub exposure at bin 1x1.
When using higher exposures (300s+) and Luminance filters, be sure to check our Telescope Information Page for the system you are using to see if it has a Non Anti Blooming Gate (NABG) or an Anti Blooming Gate (AGB). Systems with Anti Blooming Gates will be capable of longer exposure times on bright objects (like large stars) before excessive blooming during exposures. NABG systems will have blooming problems much faster then AGB systems, so be sure to use lower exposure times on NABG systems. For more information on Blooming, see our Blooming FAQ.
For Red, Green and Blue filters we suggest binning 2x2 and using exposure times of 120 seconds to 300 seconds per sub exposure.
For Narrowband filters Ha, SII and OIII you can start with sub exposure times of 300 seconds, however for best results we recommend exposure times around 600 seconds if using one of our internally guided systems.