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Reviving my Lightrack II that has been collecting dust for years now. Any idea if NINA's 3 point polar alignment works with the mount? also, I am planning to load it with a 2.8/300 nikkor + tc2x + Altair 533m camera, any chance it could carry the load without counterweight? |
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Hi, Ninas Three point polar alignment has a manual mode. So it should be usable with every german equatorial mount, even if it is not controllable by the software itself. But I never tried it myself. I do not own a Lighttrack II mount, but I own a StarAdventurer GTI. I used this one with my Canon EF300mm f/4 lens with a ToupTek ATR3CMOS camera. Using both counterweights I got for this mount, the weight is at the edge of what it can handle. The Nikkor 300/2.8 is much heavier. Paired with the 2x converter even more. I am really sure, that the fasttrack can't handle this setup at all (even with the counterweights). You get 600mm focal length you have to stabalize and track well. This won't work. CS Christian |
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Thank you Christan. Trying to evaluate if I can postpone buying a harmonic mount another year, but eventually it seems inevitable... Spec sheets of the Lightrack are very promising, however the user base/accumulated real world experience is scarce  So far I only used it with a 6D + 2.8/200L, worked like charm without CW. The 300 of course is an other world.
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| I don't use NINA's 3-point but SharpCap's which I think it is the only one that will work right away. Or the Polar scope which is handy if you are in a hurry or can't be bothered with packing a whole sets of gizmos when travelling. There is no ASCOM driver AFAIK so NINA is out of the question anyway. As for the last question, the answer is no chance. And avoid the TC2 too (although this is not related to the mount). |
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Ah, interesting topic! I also have a Fornax Lightrack II that is gathering dust in a drawer ever since I switched to an EQ mount. It can carry quite some weight without a counterweight. I used the Lightrack on a simple but sturdy tripod, in combination with a 70mm F/6 doublet and a Sony A77II camera. The camera was mounted on an L-bracket and on another side of the L-bracket I had a guidescope with a guidecamera. With regards to "polar alignment" -> I used Sharpcap for polar alignment and this went pretty well. I assume you could use Nina's 3PPA to polar align the Lightrack, but you will need to manually move the Lightrack over it's RA-axis by pressing one of the buttons. I might give it a try on a next clear night, I do have a spare ASI120 and a guidescope that I could just mount on the Lightrack to test if it works. Do you also have the Fornax wedge for the Lightrack? I can't remember how easy it went to twist the ALT/AZI knobs in order to polar align. |
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This is what they claim on the Fornax website: |
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| A word of warning with the Fornax wedge: it is friction-driven/held which means that in order to adjust the altitude angle a careful balancing act needs to be performed. Either you PA before you mount the lens+camera/scope+camera and hope for the best when you load the imaging train (and in case of a heavy setup, CWs) or you take no chance and load everything in one go after a preliminary line-of-sight alignment so you can control the amount of torque needed to hold everything without shifting but that makes adjustments in Alt tricky. Frankly, given how expensive the wedge is a threaded adjustment would have been far more preferable. |
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Kristof Vandebeek: Yes, I got the Fornax wedge and a solid 40mm carbon tripod arrived from Ali about a month ago! Now I am evaluating if I must shell out £1k++ on a travel mount that needs guiding even for a 200mm telephoto and veeery likely will be phased out by significantly improved PE models or I could make use of the gear I got already. Not ideal, as no goto, heavier because of the CW, but might be feasible and I hop on the strain wave train a little later. The manual mode is indeed there in NINA as Christian mentioned, never tried it as my boat anchor heq5 is fully compatible with the computer gear. andrea tasselli: Yeah, I remember this from my trials in Fuerteventura, 5(?) years ago (what skies mg...)! Need Hulk strength to tighten those screws if you want to make sure... I won't invest more in this one though, going strain wave next. |
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Kristof Vandebeek: |
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Yeah, that SHOULD cover my proposed gear even with a margin of error. However, I recall the mount slips fairly easy. For a friction mount exact balancing is critical, even more so for a mount as small as this. So far I have been successful with a 3 kg payload (and CWs). |
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andrea tasselli:Yeah, that SHOULD cover my proposed gear even with a margin of error. However, I recall the mount slips fairly easy. The spec sheet is certainly more encouraging but yet to see that confirmed... I am not a fan of gimbal heads (too big, too much windage), but this one looks great, apparently no CW, Canon 7D, 2.8/300, TC1.4: https://clarkvision.com/articles/portable-astro-landscape-wildlife-setup/ |
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I have used a Fornax Lighttrack with a 400mm lens and crop sensor camera, and upto 2 minute sub exposures. The wedge is not very good for polar alignment. If you align before mounting the camera, you'll lose PA and fine adjustments in altitude are hard to make. Nonetheless, with effort, you can make it work. I used it for the recent eclipse too. NINA's 3PPA in manual mode should work. Example deep sky image: https://www.astrobin.com/383940/?nc=&nce= |
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Kristof Vandebeek: Based on my experience, I’d say those specs for duration and focal length are extremely ambitious to the point of false advertising. |
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Arun H: Which 400mm lens are u using and what kind of head? With or without CW? Sorry for the loads of ???marks  |
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| I use a Manfrotto XPRO. Tripod plate is square to prevent slipping. No CW but I use a tripod ring so the camera and lens are reasonably well balanced about the point of rotation. I’ve used it with a 7D Mark II and 5D Mark IV. Lens is a 400mm f/5.6L. |
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| Re Payload: I just realized, MOMENT ARM is what counts. I currently have two not-optimal mounting solutions for my Lightrack: a ball head (short moment arm) and a Pentax Giro WR Alt-Az head (approx 2x longer moment arm). For testing, I mounted my Sigma 150-600S lens (approx 3kg): with the Pentax head the mount almost immediately started to slip! Meanwhile on the ball head even when positioned on the side the mount remained well in position. Unfortunately thanks clouds zero chance to test it under the stars for the next couple of days, weeks... |
20.21
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NINA polar alignment routine is wonderfully easy and equally as inaccurate. I highly recommend you choose any other method out there. Sharpcap is very good. Drift align is very good. Polar scopes are generally decent. Pempro is very good. NINAs routine needs some help to be more reliable. I've tried it many times over the years and it's always way off. Last attempt was two weeks ago and it was off by 10 minutes in altitude! Good luck! Ps- I've also had good luck with polemaster! |
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A nikkor 300/2.8 is a heavy lens, but more importantly, exceptionally front heavy... I'm not sure I'd want to be putting that on any mount without some form of counterweight to counterbalance the system... That's my 2c worth on that bit of the story.. As others have said, if you put NINA's TPPA into manual mode, the mount doesn't even need to be connected to the mount - you can just manually move the mount 10° around the RA axis 3 times, then from that result, dial in the PA.... Just because you can run a load on a mount without any form of weight, doesn't necessarily mean you should... |
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Just as with strain wave mounts, I was wondering even if I add counterweight, I may not need to perfectly balance the gear, saving 2-3kg worth of travel weight. The total will be around 5kg/11lbs, right now doing my research how to keep the moment arm as short as possible. Also, the lens came with an arca Swiss plate that's just long enough to keep its center of gravity in a way that DEC is balanced. Quite solid but not superstable, will be eventually replaced by a rig like this: https://www.cloudynights.com/topic/763784-mounting-camera-lenses-to-german-equatorial-mounts/?p=10996770Alex Nicholas: |
