· Get a Cloudy Nights T-Shirt · Submit a Review / Article    Click here if you are having trouble logging into the forums Cloudy Nights - Official Forums of the 2009 International Year of Astronomy Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu.... uh, User   You are not logged in. [Login] Forum Archives · Entrance · Main Index · Search · New user · Who's Online FAQ · Calendar Astrophotography and Sketching >> DSLR & Digital Camera Astro Imaging & Processing Previous   Index   Next   Threaded   Pages: 1 Prof M member Reged: 07/26/09 Posts: 49 Loc: Southwest Utah Modified 40D?       #3419454 - 10/30/09 12:48 AM Edit   Reply   Quote Quick Reply   I have a Canon 40D and have noticed a number of posts where the camera was referred to as a "modified" 40D. Just how is a 40D (or any DSLR) modified for astrophotography? Thanks! Post Extras:       JSeay86 super member Reged: 04/26/09 Posts: 133 Loc: Norman, OK Re: Modified 40D? [Re: Prof M]       #3419492 - 10/30/09 01:34 AM Edit   Reply   Quote Quick Reply   These cameras come stock with an IR blocking filter. This blocks Hydrogen-alpha emissions which are common in many nebula. Modified means they removed this filter and replaced it. See here for more -------------------- Jared Orion XX12 Dob Ten Acre Observatory Edited by JSeay86 (10/30/09 01:35 AM) Post Extras:       Prof M member Reged: 07/26/09 Posts: 49 Loc: Southwest Utah Re: Modified 40D? [Re: JSeay86]       #3424078 - 11/01/09 04:37 PM Edit   Reply   Quote Quick Reply   Thanks for the information, Jared. Very helpful link. Keith Post Extras:       nofxrx Vendor (HyperCams & Mods) Reged: 07/12/05 Posts: 2501 Loc: Palm Bay,Florida Re: Modified 40D? [Re: Prof M]       #3424483 - 11/01/09 08:39 PM Edit   Reply   Quote Quick Reply   It is not entirely correct to say that the stock filters block IR only.The filters that you replace the stock filter with is an "IR Block Filter" made by Baader(this is the most widely used,accepted filter for AP use since it opens your sensor up to the entire spectrum,while blocking only IR,and it is the same thickness as the stock filter,which means that the AF on your cam will work as perfectly as it did before the mod).. Infact the stock filters block alot more than just IR: They block everything below ~400nm,and everything above ~650-700nm(granted that is the majority of wavelengths that we use anyways..lol)..but they also block a certain level of each wavelength in between those lines.This is to keep the sensor's "view" the same as our "white light evolved receptors/cells" in our eyes.. You gain so much from removing those stock filters for AP use that it really doesnt make sense NOT to.In fact,with all the technology today,with things like a custom white balance,"stock replicating filter" like the X-nite CC1 Filter,you can still use your expensive camera for all the daytime imaging you want with absolutely no hinderance in performance. So,my point is simply,if you are interested in doing DSLR AP,think about modding your cam,or having someone do it for you(like the link to Hap's service.although,there are a ton of "one man shows" that also do these mods for much cheaper) .There are plenty of instructional tutorials online for just about every model Canon and Nikon out there.. But,go with a Canon.They are the absolute best performers for AP.period. Hope this helps.... CS! -------------------- Brent Oliver WO-66SD*WO-Megrez102ED-Special Edition*Super C8 Plus* CGE Pier-Mounted Some Cameras,some Filters HyperCams&MODS My Gallery Post Extras:       JSeay86 super member Reged: 04/26/09 Posts: 133 Loc: Norman, OK Re: Modified 40D? [Re: nofxrx]       #3424816 - 11/02/09 12:25 AM Edit   Reply   Quote Quick Reply   Brent, thanks for clearing that up, your post was very informative! -------------------- Jared Orion XX12 Dob Ten Acre Observatory Edited by JSeay86 (11/02/09 12:30 AM) Post Extras:       supercoolone member Reged: 07/25/07 Posts: 93 Re: Modified 40D? [Re: JSeay86]       #3442789 - 11/11/09 08:08 PM Edit   Reply   Quote Quick Reply   Please have a look at the following: http://astrosurf.com/buil/baader/eval_us.htm This is from the creator of IRIS, I believe, it posts spectral shots with/without IR cut filter. one more page related to filters http://astrosurf.com/buil/filters/curves.htm#Protocol Edited by supercoolone (11/11/09 08:21 PM) Post Extras:       nofxrx Vendor (HyperCams & Mods) Reged: 07/12/05 Posts: 2501 Loc: Palm Bay,Florida Re: Modified 40D? [Re: supercoolone]       #3442972 - 11/11/09 10:06 PM Edit   Reply   Quote Quick Reply   Jared, Not a problem..I am just glad it was useful to someone I have been modding cams for ~4 years.First my my brand new Nikon D50(same sensor as the QHY8,SX-MX25C,etc).. It was so much fun modding that I decided I wanted to do it again...and again,and again.... Prof M, Try to look at it like this..: You can start out using the cam unmodded and get "aquainted"/the swing of things..then,once you are ready to take the next step,get your cam Modded.. Or,you can start out with the modded cam,and the only thing holding the progress of your imaging back is your own lack of experience...which,that comes pretty quickly and with images that you are proud of(thanks to the amount of signal in the modded cam) it also encourages your progress.. Good luck. I sent you a PM... CS! -------------------- Brent Oliver WO-66SD*WO-Megrez102ED-Special Edition*Super C8 Plus* CGE Pier-Mounted Some Cameras,some Filters HyperCams&MODS My Gallery Post Extras:       Pages: 1 Previous   Index   Next   Threaded   Extra information 14 registered and 7 anonymous users are browsing this forum. 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