{"product_id":"idas-odw-clear-optical-distance-filter","title":"IDAS ODW Clear Optical Distance Filter","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eClear filter that compensates for optical distance when swapped with another filter such as an IDAS NB2-PM or NB3-PM\u003c\/li\u003e\n\u003cli\u003eAvailable in 6 formats for telescopes, filter drawers, and lens adapters\u003c\/li\u003e\n\u003cli\u003eOffered in 2.0mm and 1.1mm substrate thicknesses\u003c\/li\u003e\n\u003cli\u003eDZ format provides a large 47mm effective aperture\u003c\/li\u003e\n\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eDownloads\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eIDAS ODW Clear Optical Distance Filter\u003c\/h2\u003e\n\u003cp\u003eThe IDAS ODW is a clear filter. IDAS designed it to compensate for the optical distance when another filter, such as an IDAS NB2-PM or NB3-PM, is swapped out for the ODW. It comes in six formats with 2.0mm or 1.1mm substrates, and the DZ drop-in version has a 47mm effective aperture for ZWO filter drawers.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eThe \"Optical Distance Worker\": Maintaining Parfocal Focus with 2.0mm and 1.1mm Substrates\u003c\/h3\u003e\n\u003cp\u003eThe \"ODW\" in the name stands for Optical Distance Worker. When you insert any filter into a light path, its glass substrate slightly shifts the focal point. To keep your system parfocal—meaning all filters come to focus at the same point—your empty or \"clear\" filter slot must contain a piece of glass with the same optical thickness as your imaging filters. The ODW is that piece of glass.\u003c\/p\u003e\n\u003cp\u003eBy swapping an IDAS NB2-PM or other narrowband filter with an ODW filter, you compensate for the change in optical distance. The substrate is 2.0mm in most formats and 1.1mm in the DS format.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eSix Formats for Six Distinct Imaging Systems\u003c\/h3\u003e\n\u003cp\u003eThe ODW comes in six formats. Drop-in adapters and filter drawers are sold separately.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e2\" (M48) and M52 Mounted:\u003c\/strong\u003e Standard threaded cells with a 2.0mm substrate, designed for filter wheels and drawers that accept 2\" or 52mm filters.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDS Drop-in:\u003c\/strong\u003e A 1.1mm substrate filter for the IDAS AD42-DS drop-in mount adapter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDi2 Drop-in:\u003c\/strong\u003e A 2.0mm substrate filter designed exclusively for the IDAS AD19.4 drop-in adapter for the Celestron RASA 8 astrograph.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDRT Drop-in:\u003c\/strong\u003e A 2.0mm substrate filter in a frame compatible with the Canon EF-EOS R, Meike MK-EFTR-C \/ MK-EFTE-C, and Kolari EF-EOS R drop-in filter mount adapters.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDZ Drop-in:\u003c\/strong\u003e A 2.0mm substrate filter in a frame made for ZWO FD-M54-II and FD-M42-II filter drawers, as well as ZWO's Canon EF and Nikon F lens adapters that incorporate a filter drawer.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eDZ Format Advantage: A 47mm Aperture for Full-Frame Sensors\u003c\/h3\u003e\n\u003cp\u003eFor imagers using full-frame cameras with ZWO's M54 or M42 filter drawers, the DZ drop-in format offers a significant advantage. The IDAS DZ frame has an effective aperture of 47mm. This is larger than the clear aperture of standard M48 threaded filters, reducing the chance of vignetting (darkening in the corners) on large, full-frame sensors.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eCare and Cleaning for IDAS Interference Filters\u003c\/h3\u003e\n\u003cp\u003eIDAS recommends this cleaning procedure.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eStep 1: Dust Removal:\u003c\/strong\u003e Always begin by using an air blower to remove any dry, gritty particles from the filter surface.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStep 2: Stubborn Stains:\u003c\/strong\u003e If stains remain, use a lens cleaning paper lightly impregnated with a neutral (non-acidic, non-alkaline) lens cleaning fluid. Wipe gently and slowly.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStep 3: Silicone Cloth:\u003c\/strong\u003e Alternatively, after blowing off dust, you can gently wipe the surface with a clean, silicone-impregnated lens cleaning cloth.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the main purpose of the IDAS ODW Clear Filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003eIDAS ODW (Optical Distance Worker)\u003c\/strong\u003e is a clear filter used to maintain parfocal performance in an imaging system. IDAS designed it to compensate for the optical distance when another filter, such as an IDAS NB2-PM or NB3-PM, is swapped out for the ODW.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDo I need the IDAS ODW filter if I only use one filter at a time?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIf you only ever place one filter in your imaging train and do not use a filter wheel or drawer, the ODW is not necessary. Its purpose is to fill an empty slot in a multi-filter setup (like a filter wheel) to ensure focus remains constant when cycling between your imaging filters and a clear channel.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eI have a ZWO FD-M54-II filter drawer and a full-frame camera. Which IDAS ODW format should I choose?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYou should choose the \u003cstrong\u003eDZ drop-in\u003c\/strong\u003e format. It is designed specifically for the ZWO FD-M54-II and FD-M42-II filter drawers. The DZ format features a large \u003cstrong\u003e47mm effective aperture\u003c\/strong\u003e, which helps prevent vignetting on full-frame sensors.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I use the IDAS ODW Di2 filter with my Celestron RASA 8?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003eDi2 drop-in\u003c\/strong\u003e filter is designed to be used with the \u003cstrong\u003eIDAS AD19.4 adapter\u003c\/strong\u003e (sold separately), which connects M42-threaded cameras to the RASA 8. The Di2 filter simply slides into the slot on the AD19.4 adapter.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eAre the required drop-in adapters or filter drawers included with the IDAS ODW filter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo. The IDAS ODW filter is sold as a standalone filter in the format you select. You must purchase the corresponding adapter (e.g., IDAS AD42-DS, Canon EF-EOS R adapter) or filter drawer (e.g., ZWO FD-M54-II) separately.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eIDAS (ICAS Enterprises, Japan)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Type\u003c\/td\u003e\n\u003ctd\u003eClear \/ Parfocal Spacer (Optical Distance Worker)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2\" (M48) Format\u003c\/td\u003e\n\u003ctd\u003e2\" (M48x0.75) threaded cell, 2.0mm substrate\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eM52 Format\u003c\/td\u003e\n\u003ctd\u003eM52x0.75 threaded cell, 2.0mm substrate\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDS Drop-in Format\u003c\/td\u003e\n\u003ctd\u003eFor IDAS AD42-DS drop-in adapter, 1.1mm substrate\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDi2 Drop-in Format\u003c\/td\u003e\n\u003ctd\u003eFor IDAS AD19.4 drop-in adapter for RASA 8, 2.0mm substrate\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDRT Drop-in Format\u003c\/td\u003e\n\u003ctd\u003eFor Canon EF-EOS R, Meike, and Kolari drop-in adapters, 2.0mm substrate\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDZ Drop-in Format\u003c\/td\u003e\n\u003ctd\u003eFor ZWO FD-M54-II \/ FD-M42-II drawers \u0026amp; ZWO lens adapters, 47mm effective aperture, 2.0mm substrate\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eIDAS ODW Clear Optical Distance Filter\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1 (format chosen at checkout)\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul style=\"list-style: none; padding-left: 0;\"\u003e\n\u003cli style=\"margin-bottom: 1em;\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/idas-drt-drop-in-filter-manual.pdf\" target=\"_blank\"\u003eIDAS DRT Drop-in Filter Manual\u003c\/a\u003e\u003c\/li\u003e\n\u003cli style=\"margin-bottom: 1em;\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/idas-dz-drop-in-filter-manual.pdf\" target=\"_blank\"\u003eIDAS DZ Drop-in Filter Manual\u003c\/a\u003e\u003c\/li\u003e\n\u003cli style=\"margin-bottom: 1em;\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/idas-ad19-4-adapter-rasa8-manual.pdf\" target=\"_blank\"\u003eIDAS AD19.4 Adapter for RASA 8 Manual (for Di2 filters)\u003c\/a\u003e\u003c\/li\u003e\n\u003cli style=\"margin-bottom: 1em;\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/idas-ad42-ds-drop-in-adapter-manual.pdf\" target=\"_blank\"\u003eIDAS AD42-DS Drop-in Adapter Manual (for DS filters)\u003c\/a\u003e\u003c\/li\u003e\n\u003cli style=\"margin-bottom: 1em;\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/idas-filter-cleaning-procedure.pdf\" target=\"_blank\"\u003eIDAS Filter Cleaning Procedure\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eContact us for warranty details.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"IDAS","offers":[{"title":"2\" (M48) mounted","offer_id":68030138089757,"sku":"IDA-ODW-48ST2","price":108.0,"currency_code":"USD","in_stock":true},{"title":"M52 mounted","offer_id":68030138122525,"sku":"IDA-ODW-52ST2","price":111.0,"currency_code":"USD","in_stock":true},{"title":"DS drop-in (IDAS AD42-DS)","offer_id":68030138155293,"sku":"IDA-ODW-DS","price":111.0,"currency_code":"USD","in_stock":true},{"title":"Di2 drop-in (IDAS AD19.4 \/ RASA 8)","offer_id":68030138188061,"sku":"IDA-ODW-Di2","price":150.0,"currency_code":"USD","in_stock":true},{"title":"DRT drop-in (Canon EF-EOS R)","offer_id":68030138220829,"sku":"IDA-ODW-DRT","price":150.0,"currency_code":"USD","in_stock":true},{"title":"DZ drop-in (ZWO FD-M54-II)","offer_id":68030138253597,"sku":"IDA-ODW-DZ","price":150.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/idas-odw-clear-optical-distance-filter-1.png?v=1794332106","url":"https:\/\/davidastro.com\/en-us\/products\/idas-odw-clear-optical-distance-filter","provider":"David Astro","version":"1.0","type":"link"}