Deadlake
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6" Refractor vs 10-12" Dobsonian
Deadlake replied to chrispj's topic in Discussions - Scopes / Whole setups
Amazing home build!!!! 😀 How high is the eye piece off the ground, do you need to use a step to use it? It's the one thing thing that puts me off Dobs. -
OK-1 and OK-4 are more akin to Takahashi Fluorite lens then FPL series of glass. I think Daniel Mounsey did a shoot out of all 4" APO's in a rolling review on CN, and in the end it came down to the TSA-102 and the LZOS. Unless you have all the scopes (Daniels review stretched into 30-40+ scopes, some the same model) you can to review an objective rating is hard to make.
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6" Refractor vs 10-12" Dobsonian
Deadlake replied to chrispj's topic in Discussions - Scopes / Whole setups
You forgot contrast, which also means smooth mirrors or something else without an obstruction .. 😀 On balance a really smooth reflector is best value approach to finding and observing DSO. -
Carbon for me, the nudge test result would be very similar, why carry an extra 5 kg with the wood? But the wood does look better. 😃
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In the market for a new mount. Help me spend my money
Deadlake replied to wouterdhoye's topic in Discussions - Mounts
Going back again I would of been tempted by AJX over SXP2, the extra capacity opens up what scopes you can mount. @JeremyS The mount is flexiable, you can attach whatever saddle you want by hex screws, similar to Takahashi mounts. Gives great flexiability. Your favourite Takahashi dealer in Osaka sells Takahashi scopes with Vixen mounts by default! Interested in how the carbon tripod works out, I’m tempted to buy one, however last year it’s been what has the postman bought today. 😃 Not shown but I have the half pillar extension, very much worth purchasing. -
Show me your eyepiece/accessories case, please.
Deadlake replied to Leegsi's topic in DIY Astronomer
This bag has more flexibility, you can buy another divider bag. See https://www.vanguardworld.co.uk/products/divider-bag-46 These are quite good to use on its own. So have hard shell for when you go to a dark site and expand by buying a divider bag. For the capacity best value I can find. -
6" Refractor vs 10-12" Dobsonian
Deadlake replied to chrispj's topic in Discussions - Scopes / Whole setups
You don't really have any issues with light pollution, relative to a lot of observers. From an aperture perspective you can choose what you would like I feel. -
6" Refractor vs 10-12" Dobsonian
Deadlake replied to chrispj's topic in Discussions - Scopes / Whole setups
While I was looking at some thing else, this came up. Since we are discussing aperture, contrast and reflectivity thought I put it in to the mix: Why Zambuto? -
6" Refractor vs 10-12" Dobsonian
Deadlake replied to chrispj's topic in Discussions - Scopes / Whole setups
Do you know the SQM where you observe? Some people think 21.8 SQM is dark and 21 SQM is dark'ish, while other count themselves luck with a sky around 20 SQM. -
Takahashi FC-100 and FC-76 advice
Deadlake replied to Commanderfish's topic in Discussions - Scopes / Whole setups
The above had turned up and works perfectly. Now can swap the UFC between a T2 or 2" without having to pull the nose out. -
6" Refractor vs 10-12" Dobsonian
Deadlake replied to chrispj's topic in Discussions - Scopes / Whole setups
Thanks thats confirmed my thoughts, the C9.25 is off the list. Open or no tube it is. -
6" Refractor vs 10-12" Dobsonian
Deadlake replied to chrispj's topic in Discussions - Scopes / Whole setups
Does anyone know how for a reflector to account for reflectance the mirror versus aperture, e.g. EdgeHD has around 82% reflectance GSO 10" F12 around 96% reflectance Edit: should of googled. https://www.cloudynights.com/articles/cat/articles/optical-theory/aperture-comparision-r1901 -
6" Refractor vs 10-12" Dobsonian
Deadlake replied to chrispj's topic in Discussions - Scopes / Whole setups
But not as fast at the GSO. I take the point for example those TS Boren power newts are very attractive, however for using on a GEM the focuser is located at the wrong place on the scope. Apart from weight I think the GSO 10" has it. -
6" Refractor vs 10-12" Dobsonian
Deadlake replied to chrispj's topic in Discussions - Scopes / Whole setups
How long does a 10" reflector take to cool down? I was thinking along the lines of a C9.25 or a GS0 10 F12 Cassegrain which I can put on a goto mount. Ps: For deep sky aperture is indeed the limiting factor, for anything planets and doubles use a refractor. -
Show me your eyepiece/accessories case, please.
Deadlake replied to Leegsi's topic in DIY Astronomer
I have around 12 normal sized EP's and 4 monster XWA sized ones. The other items would be a two 12.5 mm EP's and a binoviewer. I think I'm pretty covered. I also have a filter case. In one place is the idea, so I imagine one row will be take up with XWA's, and then two normal sized EP's per slot. Leaving space. -
Show me your eyepiece/accessories case, please.
Deadlake replied to Leegsi's topic in DIY Astronomer
The other option, a lot cheaper elsewhere is this: https://www.vanguardworld.co.uk/products/supreme-46d I like the way the divider comes out, and is then a soft bag. Interesting design. The puck foam can disintegrate with time and is not space efficent. -
Show me your eyepiece/accessories case, please.
Deadlake replied to Leegsi's topic in DIY Astronomer
I was plotting to get one of these cases: http://www.max-case.co.uk/store/p16/max505cam.html I currently have one of these https://televue.com/engine/TV3b_page.asp?id=64&Tab=_epbag but now I've got some large APM XWA's (17 cm long) they are to big for the bag even if I demote some EP's, the other option is one of these: https://televue.com/engine/TV3b_page.asp?id=64&Tab=_ethos Edit: Above no longer an option Ethos 4 mm is around 15 cm long, 2 cm too short. -
2mm Exit Pupil for DSO = Perfection?
Deadlake replied to Stardaze's topic in Discussions - Eyepieces
They're cheaper if you go to Japan: https://www.kyoei-osaka.jp/SHOP/nikon-nav-125hw.html -
2mm Exit Pupil for DSO = Perfection?
Deadlake replied to Stardaze's topic in Discussions - Eyepieces
Which one, APM has a sale, €332 + vat for 10 mm https://www.apm-telescopes.de/en/optical-accessories/eyepieces/58-74-wide-angle/other/nikon-nav-sw-10mm-eyepiece Looking around has the Nikon SW been discontinued ? -
Interesting, never knew GAS met up there. I thought GAS used Pewley Downs. Someone mentioned Painshill Park, Hatchlands maybe another option? Newlamds corner is a little limiting if you want to look north.
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The other option is Albury Health car park https://goo.gl/maps/pQxVkMQoSdzTnJNh9 Around 20.5 SQM and 22 minutes from Esher Common. Final site I’ll check is here Thursley Common Main Car Park https://goo.gl/maps/BNonT7uPxm1sLhf76 SQM 20.89 however I suspect the views will be obscured with trees. Abouth 30 minutes from Esher Common, however I don’t believe the estimate in this case.
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Astronomy sales during the pandemic. Update.
Deadlake replied to FLO's topic in Sponsor Announcements and Offers
APM has increased it prices in Europe even without the additional 25% charge to the US. Still not the scale production outside of china to produce these products, still a cottage industry. For example in the US only Astro Physics and Stellarvue have the CNC machines for producing lens, I believe there are 6 manufactures in the Far East who have CNC plant for producing lens. -
Astronomy sales during the pandemic. Update.
Deadlake replied to FLO's topic in Sponsor Announcements and Offers
I thought there was a global semiconductor drought going on??? Maybe over productions, you can always get a good deal on last years model for sure... -
Also known as band shift in narrowband filters. The narrow band filters consist of dozens to hundreds of 1/4 wave thick medium of different refractive indexes. When light passes normally (90º) through the filter each refractive layer is seen by the passing light as a 1/4 wave. When the light is non normal (less than 90º) each layer appears to be thicker and this added thickness changes the spectral band admitted by the filter. This thickening red shifts the admitted spectrum. At any given focal ratio, sine(theta) = (D/2F) = 1/2f#, where theta is the maximum ray angle, D is the entrance pupil diameter and F is the system effective focal length. The lower the focal ratio, the steeper the rim ray angle and the greater the wavelength. Low f/# lenses are not compatible with narrow bandpass filters. @PeterW Thanks you pressed enter while I was formatting...
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I did read this thread a couple of months ago. I did get the impression that the word electronic precludes NV picture being published in the DSO section. I suspect that the people in question might have push to or go to electronic mounts but of course this is over looked in this case. If I'd spent my budget on a 24" dob and then NV came along then I would be pretty miffed as for the same cost I could see a lot more using new technology and a more lightweight scope like a C9.25 as commonly used in the USA. I also get the impression that this was imposed by non NV users on the small NV community here and I do see more UK NV users posting on cloudy nights then SGL, so if that was the purpose it has been a great success. This is interesting so for the smaller number of objects that are served by the image scale of the fsq-85 (really its focal length?) is a better option. Noise I presume is more of an issue with your London 18.5 SQM you need the faster scope to rude the intensifiers gain. At the same F5 APO scopes are rare, if you where in SQM 20 skies whats the lower speed for a scope before noise becomes an issue, F6 which are more common?