Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.



  • Content Count

  • Joined

  • Last visited

Everything posted by Lonestar70

  1. Certainly worth a try it can only improve things by minimising reflections... not sure it will help much with the diffraction though. Moving the primary and blacking up may cure both problems with any luck. Keep Happy. Sandy.
  2. Hi Hadyn, You will almost certainly need an extension tube or you won't reach focus... the draw tube is just not long enough on the ED 80 to compensate for the focal distance lost when you remove the diagonal. I get away with a 50mm extension with my DSLR but you may need a little more for the X2 as it has a lot less depth from the front face to the sensor...My Nikon has 46.5 mm sensor depth but the X2 is around 17 - 19mm I believe. Clear skies. Sandy.
  3. Be very carefull if you take a hacksaw to the draw tube... take too much off and you can end up with the draw tube disconnecting from the support rollers when you rack outwards... the rollers are quite widely spaced on this focuser. Moving the primary mirror is the better option, although neither should/would be necessary if SW had designed the corrector properly... it is not a particularly cheap item after all. Yes I agree there could be a small element of drift included in the OP's photo, but I think the main problem is the draw tube protrusion. Clear skies everyone. Sandy.
  4. Hi Jonathan, Plenty of data on rechargeable D cells here: - http://www.componentshop.co.uk/d-size-10000mah-nimh-battery-single-battery.html?___SID=U And I can assure you D cells are not AA cells in a different body... they can supply much higher instant current than an AA cell and also can be obtained in up to 10Ah rating. The only problem with rechargeables is the 1.2v cell voltage so you would need 5 to achieve a nominal 6v. As for your Yuasu 4 Ah Battery... be aware that the stated 4 Ah rating is at a discharge rate of 1/20 x C... which is 200ma. This capacity drops if the battery is discharged at a higher rate... e.g. if you discharge at 1/10 x C (400ma) the 4 Ah rating falls to 3.7Ah. The other issue is working temperature... the above Ah capacity figures are at 25 deg C... this will fall considerably at 0 deg C or lower. I would say that you would at best get 2 hours use from a 4 Ah battery in the cold of night before it discharged to the minimum recommended voltage of 1.75v per cell... (a 6v battery has 3 cells so 5.25v) if you discharge below this you will damage the battery. You would probably be better of with a higher Ah SLA... say 10 or 12 Ah. Lithium batteries have good capacity even at low temperatures but are much more demanding about minimum voltage and charging regimes... they are also considerably more expensive... as are proper chargers for them. I attach the Yuasu data sheet for the battery you are looking at... take a look at the discharge curves which will show you the times at different discharge rates. I hope this is of some help. Best regards. Sandy. AMP9218_UK.pdf
  5. Hi Magnus_e, Nice idea, but I am affraid it won't work very well for 2 main reasons. 1/ You will be hard put to reposition your mount within more than a few arc seconds every time. 2/ The handset cannot store terrestrial objects co-ordinates (at least my SW one can't) it only stores celestial ones and these change slightly on an hourly/daily basis due to the movement of the earth around the sun. Yes you could sync on a terrestrial object, but it would not know it was terrestrial and would store the celestial co-ordinates for the position the scope was pointing too at sync...when you ask the got to go to it the next day, or whenever... the goto system would use the current time and date to calculate the new location for this stored object (which will have moved relative to the earth) and go too it.... meanwhile the terrestrial object will still be in the same place. Sadly the only way to get perfect alignment is to re-do it every time your set up... unless you have the luxury of a fixed observatory, but even then it pays to re-do the alignment every few months... the earths axis does change very slightly over time. Keep happy and clear skies. Sandy.
  6. Hi Matthew, I assume you are using the SW coma corrector with 0.9x focal reduction which is the one SW specify for the PDS scopes. You must use the special M48 camera adaptor ring with this (it is not a standard T2 camera adaptor) or you will not get the required spacing of 55mm necessary to achieve a flat field. Filters screw directly into the front of the coma corrector (focusser end). I have one on my 150pds and have found a problem with it which is due to the x0.9 focal reduction... this focal reduction creates a problem where, with the camera in focus, the focuser is almost all the way in (on my 150PDS the focuser only has approx 3 or 4 mm of inward travel left)... thus the focuser barrel protrudes too far into the scope body. This results in a small nibble being taken out of any star images (all stars are effected) making them look elongated. When I zoom in on your image I can see just such a nibble on all the stars in it (just on the left side of each star)... which is making them look elongated vertically. This is a known problem with this coma corrector/PDS scope combination and SW have not appeared to have done anything about it... they have really dropped the ball on this one. The only possible cure I have read of (other than cutting a bit off the inner end of the focuser barrel) is to re-collimate the scope with the main mirror as far up the tube as possible... this pushes the focal point a little further out and the focusser barrel can then be a little further out when the camera is in focus. The better cure would be for SW to make the coma corrector either without the 0.9x focal reduction which would bring the focus point further out or to re-design it in some other way so that it does not cause the problem... I won't hold my breath on either option being done. I am going to try the re-collimation method and see if it does enough to cure it... failing that I will change over to a Baader coma corrector which has no focal reduction and also has a longer backfocus distance. I hope this helps. Best regards. Sandy.
  7. Hi Scorpius, Unfortunately it does not only apply to edge HD scopes. When it comes to Focal reducers, Field flatteners and Coma correctors there is always a specified tolerance on the distance between them and a camera sensor involved... regardless of the type/model of OTA. All versions/models have a range of tolerance on spacing which varies with type and camera sensor size... some models are more tolerant of error than others it's just a matter of finding the correct spacing to suit your own set-up. At least with the edge HD you have 105mm +/- 1 - 3mm to play with... my ED80 field flattener/focal reducer only has 55mm +/- 1mm to fit everything into... with a Nikon taking up 46.5mm of this it makes fitting an OAG pretty well impossible. Starting with equal spacing for both cameras with an OAG is probably not a bad thing providing that the spacing chosen is within the specified focal range limits (the same would also apply without a focal reducer except that the image focal distance would be greater at 133mm with the HD)... but be prepared to adjust one or both cameras to get the flattest possible field on the camera sensor. The Guide camera is not quite as bad in this respect since it is quite normal for the chosen guide star to be slightly out of focus rather than a sharp pin-point... most guide software tends to work better this way... so, get your imaging camera spot on and then adjust the guide camera as necessary... after all, you are not going to worry about a small amount of field curvature or coma at the edges of the guide camera's field of view when using a guide star closer to the centre and therefore much less affected. So don't feel too bad, we all had to learn this kind of stuff... some find it easy... some of us the hard way (including me on several occasions ), but it all comes right eventually. Keep happy and hope you have many clear skies. Best regards. Sandy.
  8. Hi, No, it does not work quite like that... the native focal length of the H8 gives an imaging backfocus of 133mm @(F10)... when you add the 0.7 focal reducer this changes to 105mm @ (F7)... and represents the distance behind the focal reducer where the image is flat all over... less or more will result in image degradation. There is a small tolerance on this of +/- 1 - 3mm depending on camera sensor size... the larger sensors on a DSLR requiring the closer tolerance in spacing... +/- 1mm. As I said in my previous post the OAG prism does not come into the equation for the positioning of the Imaging camera, which needs to be within the above tolerance allowance or you will get image degradation on the outer edges (field curvature)... It is usually better to er on the short side than the long when setting the spacing, in order to avoid focuser travel problems. The OAG prism does not alter this focal distance but, for the guide camera the spacing allowance could be higher (up to +/- 3mm) due to the smaller sensor size. Given this, then the final distance from prism to either camera sensor could well be different, although I would not get hung up on the prism distance, since it has little to do with where the image is located, distance wise, relative to the focal reducer... this is fixed by the reducer. Yes you can go further or nearer than the 105mm but you will not get an undistorted image. I hope this helps. Best regards. Sandy.
  9. Hi, The OAG prism has no influence over the distance from focal reducer to imaging camera sensor, this is entirely dictated by the focal reducers backfocus requirements... i.e the OAG prism is not in the imaging cameras field of view. The prism projects into the light cone coming from the focal reducer (usually in a position where it is not directly in line with the imaging cameras rectangular sensor area) this merely turns the picked off light through 90degrees and up into the guide camera sensor which should be at the same 105mm as defined by the focal reducer... it does not change the focal length. Whether this works out as being the same distance from the prism to the 2 sensors is by the by... the controlling element is the focal reducers backfocus requirement. It is much the same as a flip mirror diagonal but without needing to flip. Best regards. Sandy.
  10. Hi Guy's, According to Celestrons specification data for the 0.7 focal reducer (see attached) the backfocus requirement is 105mm not 133mm. There should be no problem using a Nikon camera which has a flange to sensor distance of 46.5mm... just add spacers to achieve the 105mm required by the reducer. (= 58.5mm spacer length) If you are using an OAG as well then the optical width of this (and any other adaptors) should be subtracted from this spacer length. http://www.celestron.uk.com/en/pdf/Edge_8_HD_Reducer_Lens.pdf The guide camera will also need to have it's sensor plane at 105mm from the focal reducer so you will need to calculate the spacer length to achieve this (most CCD guide cameras have a flange to sensor distance of around 17 - 19mm... check your manual)... you will also need to subtract the optical path length of the OAG via it's prism to it's output flange. Hope this helps. Good luck and clear skies. Sandy.
  11. Hi Cam, Sounds like a driver problem... not uncommon with XP pro. Did you load specific drivers for the camera when installing the capture software or did you let windows choose when you plugged in the camera?... if the latter then it will pay to reload the drivers from a disc from the programme manager... scroll down to the camera and right click... this will bring up the properties and show which driver is assigned (also the port number allocated)... you can also choose to update the driver if it is showing the wrong version. Have a look at this: - http://www.cyanogen.com/help/maximdl/Starlight_Xpress_HX9_USB.htm You will see a reference for the SX Universal upgrade and driver... the original drivers are pretty obsolete. http://www.cyanogen.com/help/maximdl/Starlight_Xpress_Universal.htm You may also need to tell your capture programme the specific port number allocated to the camera... autosearch features don't always find it. This may sort your problem. Good luck. Sandy.
  12. Hi Vox45, Are you asking Startech about the correct USB hub?... they make many different ones. The type you need are the 'INDUSTRIAL' type which have a separate input voltage terminal block for an external DC power source of between 7 - 24v. These are available in either 4 port or 7 port versions and YES they do have a switched mode down converter fitted internally to provide +5v for the USB ports. They also make 'Consumer' versions of these... but they do not have a down converter... instead they provide a mains powered power supply which outputs +5v... however, these versions cannot be powered from an external 7- 24v DC source directly, they would need a step down regulator for +5v. Both types can be powered via the USB bus from the PC/laptop... (limited to a total of 500mA... which is shared between all the ports) None have fuses fitted... so (assuming you are using an 'Industrial' version) you would need to fit a fuse in the +12v input line from your battery which should be rated at 2 Amp for a 4 port hub... or 3.5 Amp for a 7 port hub. Here is the spec sheet for the 'Industrial' 7 port version... the 4 port is the same other than having fewer ports. http://cc.cnetcontent.com/inlinecontent/mediaserver/stech/703/6a5/7036a576c4e84aa9bc2de1bba8487a5b/original.pdf I hope this helps. Best regards. Sandy.
  13. Here you go... http://www.altecautomotive.co.uk/standard-blade-type-fuse-holders--fuses-59-c.asp If you use XLR sockets make sure you use a different pin count for the main battery input (say a 4 way or a 5 way and use 2 pins for + and 2 pins for -) and 3 way versions for your 12v outputs etc... but only wire to the 2 outside pins... that way you cannot plug the main battery into the wrong socket in the dark... and you can't put the 12 volt output plugs in the wrong way round. good luck with your build. Best regards. Sandy.
  14. Something wrong with your link kalasinman... cannot be opened. 404 error 'not found' Sandy.
  15. Check first... M42 screw mount is 42mm x 1mm pitch. T2 is 42mm x 0.75mm pitch... you can't use one with the other. The only one I know of is the Geoptics one for Nikon lenses. Hope you find something. Sandy.
  16. That sounds like a better/safer option. Sandy.
  17. It may have the Prolific chipset inside... not the same as FTDI and uses different drivers. In any case, you would still need the USB connector to connect to your PC... the RJ45 would connect to the RS232 side of the adaptor. You would need to be sure which wire was which and also the voltage levels from the RS232 side. RJ45 EQDIR pins: - 1 = gnd 2 = n/c 3 = n/c 4 = gnd 5 = txd 6 = rxd 7 = 12v 8 = 12v Hope this helps. Sandy. EDIT. You could check the pinout by using a multimeter on your RJ-11 handset cable... which would normally attach to the USB-RS232 adaptor. The RJ-11 pinout is: - 1 = n/c 2 = rxd 3 = gnd 4 = n/c 5 = txd 6 = n/c Just check which wire on the RJ=11 connects to which pin on the RS232 end... then wire the RJ45 to suit. You can probably ignore the 12v connections on the RJ45 in this application... the converter gets it's power from the USB side on your adaptor and the mount gets it's supply from a separate source.
  18. OOps...My Apologies... yes you are correct, I was thinking of the handset connection to the PC serial port, which is RJ-11. Whilst it is in fact an RJ45... I am not sure the cable connections are the same... I am inclined to believe the mount needs a straight through connection rather than the cross-over consol type. The schematic on ASCOM should show the correct conections for this. Good luck. Sandy.
  19. Even the NEQ6 does not have a true serial port. The only thing in common is the use of a DB9 connector... this does not mean it is an RS232 port and is also wired differently...it also has very different voltage tolerance. Sadly it is a mistake a good few users have made... with the inevitable high cost of replacing their mounts motherboard. Always check your manual... don't assume that becouse it looks the same, that it is the same. Keep Happy. Sandy.
  20. Hi Guy's, It may be a lot cheaper, however, be very aware that this cable may damage your mount... The FTDI FT232R chip alone would be fine which is what the EQ Direct cable does (it only outputs 0V to + 5v)... however this cable is combined with a ZT213 RS232 level converter... this bit will increase your TX output voltages to +/- 12v ... which may well fry your mounts input... it also expects it's RX input to be in the range +/- 25v (both of these voltage levels are within the true RS232 voltage levels range). See attached Data Sheet for the ZT 2xx range. Most Skywatcher and Celestron mounts are +5v max levels for input and output signals. The mount connection type is more usually RJ-11 or a DB9... NOT RJ45... the pinout of these is not the same as the cable you are looking at... Check your SYNSCAN manual, or your mount's equiv. Be Safe... not sorry. Best regards. Sandy. ZT230E_ds.pdf
  21. You could do much worse than buying a Nikon D5200 body only (can be got NEW for less than £300.00) which can use all your lenses. For astro work you can use 'BackYardNikon' tethering software which will do everything you will ever need. You would need a DSUSB (or equivalent) usb cable release for shutter control... as you would with many Canon models. http://www.otelescope.com/index.php?/forum/6-backyardnikon/ Good luck. Best regards. Sandy.
  22. Hi Don, Just a thought... is your phone app set to give your location in Degrees, Minutes and seconds or are you actually entering decimal degrees by mistake. 92.33 deg W is 92 deg 19minutes 48 seconds W.... which is pretty close to 92 degrees 20mins W. Similarly 34.37deg N would be 34 deg 22minutes and 2 seconds N... it's an easy error to make and many off us have made it. This could account for some of the error you are getting. Best regards. Sandy.
  23. Hi There, I would be inclined to say your pictures are suffering from LIGHT POLLUTION, you certainly have a great deal of it at your site. Try taking a shot at say 10seconds rather than 30 seconds with the same iso etc as in the above frame and see what that comes out like. Also try taking the same 2 shots at a dark site... I think you will be surprised by the difference. . A couple of other points... did you turn the camera body to manual focus as well as the lens?... not sure if this is available on the D60... I have this function on my D90 and it makes a large difference to the noise if I forget to turn the body to manual. Have you turned off all in-camera noise reduction, oddly this can sometimes add noise if left on for astro shots. Are you covering the viewfinder before taking an exposure... a lot of unwanted light can get in via this route. Finally, it is possible that you have displaced the internal mirror, used for the viewfinder, when you dropped the camera... this could mean some light is getting past the mirror seal when in the viewfinder position or it is not rising to it's proper open position when in exposure position... which again could be doing strange things with the available light. This would not always be obvious when taking daylight shots, since the huge difference in available light would tend to mask it. I dont think this is anything to do with hot pixels... if the sensor had that many it would also result in very poor daylight shots. Try taking a BIAS shot ( Camera in M mode, manual focus,lens cap on, viewfinder covered, all noise reduction turned off and highest shutter speed)... this will show true number of hot pixels and noise. I hope you can find the cause and the solution. Best regards. Sandy.
  24. Hi Jazzy and welcome to SGL. That must be a first... usually it is a DSLR which has the problem of not enough in focus travel, since they all have rather large backfocus requirements. WEBCAMS on the other hand have relatively small backfocus requirements and usually need the focuser wound out more. A Barlow would sort this inward travel problem for a DSLR, by moving the image focal point futher out of the focuser, however this would probably make the available outfocus travel too little for a WEBCAM... as would shortening the truss rods, thus requiring some extension piece on the front of the WEBCAM. What scope and DSLR Camera are you using? and how are you attaching the Camera's?... have you removed the lens from the SPC900 and fitted a nosepiece? Not come accross this situation before. Best regards. Sandy.
  25. Hi Paul, Don't give up it can seem a little confusing at first but just take it one step at a time. You can run EQMod without CDC in the frame, which just adds another lot of settings to the mix... run it without and get it running on it's own... then add CDC. Looking at your screen shots it appears that you have not actually set up EQMOD... you appear to have just set up CDC and, unfortunately, a lot of this input just stays with CDC it is not automatically transferred to EQMOD. For example... your EQMOD screens show different Latitude and Longitude and also time to those shown on CDC screen shots.... These must be identical or all sorts of strange thing can happen. You must set up EQMOD first to use the correct COM port and also make sure it's coms parameters are correct. You then set CDC to the same when you set it up later. This Tutorial is a good one to follow: - http://lightvortexastronomy.blogspot.co.uk/2014/09/tutorial-imaging-setting-up-equatorial.html It is aimed at Windows 7 users mainly but does mention some thing that are different if using Windows 8. I am sure your main issue is that EQMOD does not recognise the COM port... even though CDC appears too. I hope this helps. Keep happy... we are all here to helps each other and a great many of us have been through this same setup procedure, and all had some issues to deal with. Best regards. Sandy.
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.