· Get a Cloudy Nights T-Shirt · Submit a Review / Article Click here if you are having trouble logging into the forums 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] Entrance · Main Index · Search · New user · Who's Online FAQ · Calendar Observing >> Variable Star Observing and Radio Astronomy Previous   Index   Next   Threaded   Pages: 1 | 2 | 3 | (show all) ASTERON Carpal Tunnel Reged: 11/24/07 Loc: ISRAEL Re: ST402ME NABG - suitable for photomery ? [Re: Ed Wiley]       #5402513 - 09/04/12 08:36 AM Edit   Reply   Quote Quick Reply   Hi Ed, I guess you are right about this (no response about the BVR filter wheel). I was actually hesitating about this purchase. An entire SBIG BVR filter wheel will cost about $387.00 while a single very high quality V 1.25" fIlter from Astrodon will cost $175.00 (But you don't get the B and R filters nor do you get the option to switch filters from the software). I dont think the extra cash for the BVR wheel will break me (I got the 402 for a very fair price - so I can spend a bit more on Filters). What I am worried about more is: 1) I dont know the source for the Filters in the SBIG wheel, I have read somewhere that some photometric filters and in particular the Johnson V have a tendency to Fog over time by forming some kind of chemical deposit on the glass. Will the SBIG V Filter Fog over time ? I know the Astrodon (new Generation) V filter is hard coated to prevent fogging, Since I dont want to worry about such fogging, I am tempted (However, for all I know, the filters in the SBIG wheel could be Astrodon - even though I doubt it as the cost is probably too low for making this plausible). 2) I dont know enough yet about photometry to for a clear opinion about whether the B and R Filters are going to be useful - I am still climbing the (very steep) learning curve, but have not really been able to gather enough information about this to form a clear and decisive answer). 3) The filters in the SBIG wheel are glued in place so they cannot be moved or used singly with another camera nor will they become useful if I ever change the camera or upgrade to a SBIG ST8ME or so. A mounted 1.25" V filter can be used anywhere where the filter wheel accepts standard mounted 1.25" filter. Again clear advantage for the separate mounted filter(s). Tough decisions Again, I am humbly asking for all and any input on this issue (Astrodon V versus SBIG BVR). Help and comments will be happily and thankfully accepted Thanks Lihu Edited by ASTERON (09/04/12 08:50 AM) Post Extras:       NJScope sage Reged: 03/08/04 Loc: NJ Re: ST402ME NABG - suitable for photomery ? [Re: ASTERON]       #5405106 - 09/05/12 03:29 PM Edit   Reply   Quote Quick Reply   Lihu: I've had the SBIG BVI filter wheel for over 5 years and have never had problems as you have described. Apparently some of the earlier 1.25" Schuler filters fogged over with time but as far as I know this have never been an issue with the SBIG filter wheels. By comparison, the BVI (not BVR) wheel is a bargain compared to the cost of 3 separate photometric filters. The real advantage other than cost is that points along a lightcurve can be automatically captured in succession (B,V,I,B,V,I, etc.......) in a single session such that each bandpass is temporally displaced by a few minutes rather than hours or days. This can have a significant impact for a number of reasons if you plan to model your lightcurve data. Let me add a few points regarding the use of multicolor lightcurve data. As Gavin pointed out, the B-V or V-I value for a target can be used to select comparison stars with a similar color index to improve magnitude accuracy and precision. In addition, there are many published references which tabulate B-V values and the corresponding effective temperature of a system. Single bandpass data are very useful for generating accurate time-of-eclipse or pulsation timings from variable stars. However, in order to model (Roche geometry) data from eclipsing binaries or to identify the modes of a pulsating star, multicolor photometry is necessary to get the most robust solution. Post Extras:       ASTERON Carpal Tunnel Reged: 11/24/07 Loc: ISRAEL Re: ST402ME NABG - suitable for photomery ? [Re: NJScope]       #5406054 - 09/06/12 06:03 AM Edit   Reply   Quote Quick Reply   Kevin, Thanks, your response clinches it - I will get the SBIG Filter wheel (BVI). As I am quite interested in intrinsic variables I would like to be able to get an estimate of the temperature as an important (to me) piece of data. If I ever get another Camera I may go for an Astrodon filter set ( either BVRI or SLOAN ) by that time I may know better what I am after. I will be sending the filter to A US friend where another friend will pick it up for me in November. Until then its a clear filter (No Filter, in my camera configuration) for any training sessions. By the way, I already bought a used AP 0.67X Focal reducer based on Gavin's recommendation and I will get it also in November. You guys are just great, researching alone it would have taken me at least 2-3 months to make my decisions. Now I am certain I am not making any serious mistakes in ordering stuff. On another note - while scanning Astrodon's website for photometry I saw that they are running a special sale on earlier generations of some photometry filter sets with very low prices. I thought I should mention this here if anyone is on the market for Filters - Look them up ! In about 10 days we celebrate here in Israel the Jewish New Year Holiday. I would like to take this opportunity to wish everyone in this forum (and all CN members) a happy and fruitful New Year. Thanks for all who helped with comments and advice Edited by ASTERON (09/06/12 06:10 AM) Post Extras:       ASTERON Carpal Tunnel Reged: 11/24/07 Loc: ISRAEL Re: ST402ME NABG - suitable for photomery ? [Re: ASTERON]       #5417289 - 09/12/12 01:10 PM Edit   Reply   Quote Quick Reply   Just an update, Camera has been now tested and CCDSOFT Installed on my Laptop without a single hiccup. Dark frames looks very good with no visible hotspot clusters or serious defects (Tested at 0.0 degree centigrade). All software functionalities work, so far so good. Next step will be taking some non-guided exposures of star fields to get familliar with the camera and work under real sky conditions ( Remember, these are my first CCD camera photography attempts, so don't hold your breath for results ) I also want to get a feel of choosing comparison stars and identifying target star(s) in the FOV. After my Filter wheel arrives (November ?) I will try to do some actual time series using a V filter. Edited by ASTERON (09/12/12 01:13 PM) Post Extras:       btieman scholastic sledgehammer Reged: 07/24/08 Re: ST402ME NABG - suitable for photomery ? [Re: ASTERON]       #5418083 - 09/12/12 08:52 PM Edit   Reply   Quote Quick Reply   You can do time series with a clear aperture--good enough for exoplanet work! If you have the filter, you can probably start using it right away. Just need a way to stick it in the optical path... Filter wheel really isn't needed until you need to switch between filters frequently. Even then it can be more of a problem than a help unless your filters are par focal and/or you can automate focusing. For time series, it's often better to stick to a single filter so the cadence of the images is higher. Of course the cadence required is a function of what you're trying to measure. Don't need frames every 10 seconds if the changes are measured in hours. Anyway, the point of all that was to encourage you to jump right in...the water's fine Post Extras:       ASTERON Carpal Tunnel Reged: 11/24/07 Loc: ISRAEL Re: ST402ME NABG - suitable for photomery ? [Re: btieman]       #5421871 - 09/15/12 03:13 AM Edit   Reply   Quote Quick Reply   Hi Btieman, I decided to buy the BVI filter wheel new. My take is it already has a V filter so I get the other two filters as a bonus + I get computer controlled filter changing and sequencing and hopefully parfocality of all filters. I know I can jump into the water and will do so soon. THanks for the encouragement ( I think I need it) Post Extras:       Ed Wiley professor emeritus Reged: 05/18/05 Re: ST402ME NABG - suitable for photomery ? [Re: ASTERON]       #5426567 - 09/18/12 12:33 AM Edit   Reply   Quote Quick Reply   Asteron: Good choice. The filters are parfocal, or at least I have never had to change focus when taking a set of BVI images.BTW, you might think about contacting the Baraket Observatory. Ido is a great guy and is into outreach. Happy belated New Year, Ed Post Extras:       ASTERON Carpal Tunnel Reged: 11/24/07 Loc: ISRAEL Re: ST402ME NABG - suitable for photomery ? [Re: Ed Wiley]       #5426687 - 09/18/12 03:19 AM Edit   Reply   Quote Quick Reply   Hi Ed, I do hope it is the right choice. I'll wait and see. I tried to enquire about ordering the filter wheel from our graceous host. I send them an E-mail but it's been a few days and no answer yet. Probably they have their hands full right now with the new place and the new website. I will give them a call tomorrow. BTW - I looked up their new website and to my surprize they dont have the great FOV calculator utility for CCD+telescope combinations which was so useful in their old website. I hope they bring it back sometime. Finally, I wish you a happy new year ( it still is Second Holiday here, so your wishes were not belated after all) Post Extras:       ASTERON Carpal Tunnel Reged: 11/24/07 Loc: ISRAEL Re: ST402ME NABG - suitable for photomery ? [Re: ASTERON]       #5430223 - 09/20/12 01:28 AM Edit   Reply   Quote Quick Reply   Update , BVI filter wheel ordered - will be getting it second week of October. ( SBIG are making a batch of them this week). Post Extras:       Pages: 1 | 2 | 3 | (show all) Previous   Index   Next   Threaded   Extra information 1 registered and 0 anonymous users are browsing this forum. Moderator:  RLTYS  Print Thread Forum Permissions       You cannot start new topics       You cannot reply to topics       HTML is disabled       UBBCode is enabled Thread views: 4348 Jump to *Announcements and News* -----   Cloudy Nights Announcements   Discussion of CN Articles, Reviews, and Reports   Celestial Events*General Astronomy* -----   Beginners Forum   General Observing and Astronomy   Outreach   Light Pollution*Equipment Discussions* -----   ATM, Optics and DIY Forum   Binoculars   Binoviewers   Cats & Casses   Classic Telescopes   Equipment   Eyepieces   Mounts   Observatories   Reflectors   Refractors    Video and Electronically Assisted Astronomy*Astrophotography and Sketching* -----   Beginning and Intermediate Imaging   Film Astrophotography   DSLR & Digital Camera Astro Imaging & Processing   CCD Imaging & Processing   Solar System Imaging & Processing   Sketching   Astro Imaging/Sketching Contest *Observing* -----   NEO   Planetary and Solar System Observing   Lunar Observing   Deep Sky Observing   Double Star Observing   Solar   Variable Star Observing and Radio Astronomy*Telescope Specific Forums* -----   Celestron NexStar    NexStar GPS / CPC Telescopes   Questar Forum   Meade ACF/RCX / LX / GPS    Meade ETX*Speciality Forums* -----   Arizona Science and Astronomy Expo   NEAF (Northeast Astronomy Forum) and NEAIC (Northeast Astro Imaging Conference)   AstroArt   Astronomy Clubs and Star Parties   Astronomy Software & Computers   AstroWebsites   Science! Astronomy & Space Exploration, and Others   Space Rocks   Stellar Media*Swap and Shop* -----   Shop and Swap Audio Components*CN Feedback and Vendor Announcements* -----   Vendor and Group Announcements*International Year of Astronomy 2009 - Forums are now closed.* -----   IYA Archive Info CN Forums Home

Cloudy Nights LLC Cloudy Nights Sponsor: Astronomics