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ronin

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About ronin

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  1. Eyepiece comparision tool

    I just take the object size then work out the magnification required to get that field of view in whatever eyepieces I expect to use. Sort of: M42 is a degree, in the BST's that means 60x magnification, and in the Bresser to get 60x means a 10mm eyepiece. So the 12mm BST should squeeze it all in with a small amount to spare. So I drop the 18mm in to be safe and have the 12mm to hand. Determination takes a few seconds when and if I manage to convince brain cell 1 and brain cell 2 to work together, there isn't a 3. What do people do when outside and no PC to hand? The arithmatic I find easy and I can be using anything from a 350mm FL scope to a 1500mm FL scope, and 4 options between.
  2. Is M42 around in Stockholm at present, amd surely Jupiter is below the horizon? M42 is about a degree, so that makes an image of 4.5mm across so is not going to fill a sensor frame. Planetary imaging is usually performed with a Mak or SCT and even then people add a barlow to increase the image size. So in a DSLR Jupiter is too small for deatail. In effect a different scope is required from tjat used for a DSO. Additionally for a planet it is usual that you take a video and stack and process thje best frames from the video. Again different to DSO imaging. For a DSO (M42) you need a small(ish) scope and an equitorial mount. Consider something along the idea of a 70-72mm ED refractor. You attach the DSLR via a T-ring and a nose piece. Then you set the DSLR up to operate fully manual and set ISO, Exposure etc use an intervalometer to get a series of 20 to 30 second exposures then you stack these in DSS (Deep Sky Stacker). If you are making the assumption that astrophotography is similar to photography then you have the wrong approach. It is somewhat totally different. Any clubs that you can get to, as these tend to be a source of information? The DSLR and lens will be reasonable for wide field shots, but owing to the focal length and maybe sensor size not really for specific DSO's. YTou will need a tracking mount of some variety, normal EQ or Skytracker type, but not Alt/Az. Also DSO images tend to be taken in RAW format then stacked, however DSS will stack the normal jpegs and that is a way to get initially familiar with the stacking process. Try getting a wide field shot of Casseiopia or Cygnus, say 10 exposures of 20 seconds each then load these into DSS and practise with those. Darks are easy to add. Leave the DSLR setting as they are and get say 6 darks to add to the stack.
  3. NZ 'ere I come

    Enjoy The Land of the Great White Cloud. Guess the road trip is travelling from son to Auckland for the flight back? Hope the flight is via Aus and not LA. When I visited Wellington I found that their idea of the morning rush hour and commute was different to ours. Their rush hour would have been a steady free flow of traffic here. Get some nice bits of green stone if you haven't already, think Rotorua had a good one - hold your breath there however.
  4. As already mentioned a 40mm plossl will deliver a simialr field to a 30/32mm plossl (I give it as 30/32 and never really sure there is a diffeence, they seem interchangeable). Reason is simply that a 30mm is around 50 degree and a 40mm is around 40 degree. So wehat you gain on longer focal length/ lower magnification you lose on the field stop. It also measn that a 25mm BST Starguider at 60 degrees has a filed the same as a 30mm at 50 degrees. So if finances and intentions make it plausable then a 25mm Starguider is now an option. To the other side and the "problem" of a long plossl. This is really eye placement. The eye relief of a plossl is about 2/3 the focal length. So on a 30mm that mean the eye has to be some 20mm away, on a 40mm it would be around 26mm and oftan that means the eye/head is not in contact with anything so maintaining it at a given position is difficult. You will find a lot of people like their TV 32mm plossl and at least half also complain about the eye relief with it (too much), TV sell an extender for their long plossl's for this purpose. Choosing eye pieces is not as easy as it first seems. Where are you as there may be a person/club around where someone may let you use the items mentioned. At least that way you get a brief idea of them and the suitability.
  5. skymax 127 eyepieces

    Without getting something sort of on a whim I doubt that there will be anything that is better, depending on the definition of better, then a decent 30/32mm plossl. The TV will likely be the best, or safer, option, then the Vixen NPL's. But the quality can overlap and if the one you have is good then stick with it and perhaps just keep an eye out for something potentially better. Just at those focal lengths you may not really see a noticable improvement. The "whim" comment refers to a couple of plossl's I have seen mentioned in the US, some of them go up to 56mm or thereabouts, Parks Optical. However they seem to be 2" eyepieces, sure I have read of a 1.25" at some time. Sort of thing to buy almost for the hell of it and have no expectations on it. Parks do a 50mm 1.25" plossl: ParksOptical Bottom of the page. No idea what it is like and in general keeping I deny everything, especially anything that refers or implies being a responsible and possibly sensible person. One of those eyepiece I suspect is worth having in the box of bits as a talking point. The other one is the Antares W70, they did a 25mm and with a 70 degree view, would come out wider but is the extra worth it as it is going to be small. Used to be sold by Rother Valley, however they seem to have few Antares now and I suspect that Antares may have ceased. Not sure on that specific one's performance, I have a few of the shorter focal lengths and they are fairly good, however I moved on to TV plossl's and BST's. Antares were in general good items. Should actually get myself a 25mm if at all possible, actually should look at the remainder of the set as I have 3 and think the set is 5.
  6. Andy, I made a mistake it was Astronomics I contacted about an Astro_Tech scope, not Stellarvue. Most of the remainder holds true however. I have just realised as elsewhere there is mention of new Astro Tech scopes and I had a look, and there was the one I enquired about, just made by Astro Tech not Stellarvue. Still think I gave them the wrong email however. So not going to pass any comment about their lack of response, as I half suspect they have tried and failed, and it is all my fault. Just as a point you might want to check out the Astronomics+Astro Tech scopes out as they seem to be in the process of bringing a few new model to market. I was looking at their potential new offering of a 72mm ED with FPL-53. Don't think it was Widescreen as best I recall, it really was a small company, almost the impression was a single person. All I recall was the website was poor and Widescreen have generally had a good website to visit with information and a selection of scopes. The other had very little. But it was quite a few years ago now. Don't you know anyone going for the eclipse, or better returning from it? Could put one in their bag and bring it back.
  7. Did you ask this about a week ago?? Someone did. Stellarvue used to have a stockist/distrubuter but they were a little odd in that they didn't actually stock any of the Stellarvue items. That was many years ago however. I recently asked Stellarvue about a scope and shipping it to the UK but no answer from them - will say it could easily have been my fault, slight suspecision that I gave them a sort of incomplete email address. If so then it is lost and looking for a home on the WWW somewhere. I suppose you can buy from them in which case they will ship it here and you will get charged VAT (20%) on the Scope cost + Shipping cost. There may be the odd additional charge so for safety expect to pay around 20%-25% on top. Could also check if any retailer sells and ships. When looking into the shipping I have found that FedEx seem the most capable. Intenational shipping is what they do and at least that bit has alwaays gone well with them. It is the HMRC payment side that they seem to have come to terms with. Basically they pay it, they deliver and you pay them - immediate or later. Means it is not sat around supposidely waiting for clearance. Suppose the alternative question is are there any EU sellers or distributors of Stellarvue equipment.
  8. Just comes down to scope charactoristics, the Mak's are in effet long focal length and if you swap the EP equation round then Exit Pupil = Aperture/Magnification. Since Maks tend towards large magnifications, ownig to their general long focal length, then Exit Pupils tend to be small.
  9. Newquay and Surrounding Area

    Did you look at the Kernow Astonomers webpage, well the one before it on that link? I noticed that it had to be written by someone that was unaware of the meaning of Kernow, it said: Address: Kernow, Cornwall. So it is at Cornwall, in Cornwall. Someone should notify the club list maintainers that the location is St Columb Major. I see they have a public viewing night on Sept 2nd. Seems it could be worth a visit to get a feel for them and ask a few questions. A bit like yourself I am always a bit puzzled why clubs meet for the observing during the week, one club around here have applied thought and arrange theirs for a Friday and/or Saturday. Their thinking being Friday if clear otherwise hope Saturday is better. The remainder pick Mondays and Wednesdays which is when people have work commitments the next day.
  10. How should m13 look?

    Looking at the the image here: https://en.wikipedia.org/wiki/List_of_Messier_objects M13 does seem sort of less distinct in the center portion then others, a bit diffuse I suppose. Gas/Dust ?? If you click on the M13 link down the left the specific page opens with the words: M13 was discovered by Edmond Halley in 1714, and catalogued by Charles Messier on June 1, 1764. Tend to assume that all Messier objects were found by Messier, it seems not. CM came along 50 years after EH.
  11. Mains Power to EQ5 Motors

    I have 2 of the Maplin's L06BR supplies, similar to the Amazon item. https://www.maplin.co.uk/p/20w-acdc-multi-voltage-power-supply-l06br Think they do a slightly smaller one and at times they have them reduced. Just be sure of setting the polarity correct.
  12. Prime focus usually refers to attachment of a DSLR and that in general means inward travel whereas you are describing outward travel it appears. I see you have a GT81 - is that the scope in question?. Have you got the diagonal in place? If not that is likely the reason as the diagonal will be acting as a diagonal and an extension tube. The diagonal will effectively push cameras and eyepiece outwards. If not there then yopu have to extend the focuser far enough if that is possible. WO's seem not to have a great deal of travel on their focusers. One scope I bought is actually defaulted to imaging, so to use an eyepiece and view, you have to add in one of the supplied extension tubes. First time out you are stood there wondering why the thing cannot produce a view. Eventually realisation dawns.
  13. You were likely still at sidereal but the difference really is small, I have a small goto that only has sidereal might have lunar but certainly does not have Solar - as far as it is concerned the sun does not exist in any form (Meade safety) - I have taken it to a solar viewing day and on the best alignment I managd the sun remained in view for 2 hours. Might be wrong but one rotation of the earth is 360 degrees in sidereal terms, one rotation sort of Solar (midday to midday) is about 361 degrees - orbital movement. If that is correct the Sidereal and Solar differ by 1 degrees rotation in 24 hours. Not a lot. Actually I would seriously expect that on some mounts you select Sidereal or Solar but get the same.
  14. Depending on the back - and my comment there will be expect it to never quite get back to previous, you will have to keep thinking about how you use it hereafter - I wouild suggest you go find a 150 Skywatcher dobsonian. A CPC, or Nexstar, is a chunk of telescope, they are not light and you have to either lift them up on to the mount (think of that back) or yoiu have to dcarry the scope and the tripod out as a unit. Also you will need a good power supply and assorted leads. You are used to a dobsonian, although it appears to be a goto - how important is the goto aspect? After that it will be smaller and even something like a Bresser 102 on a AZ5 mount comes out at around £350, simple, easy totally manual but I wouldn't like to go to one like that from a 250.
  15. Check for roads being closed off. In Aus at the Cairns eclipse the Police closed the roads leading in. Did it to prevent all cars piling in at the last moment and trouble starting from frayed tempers. I have read somewhere that the US police may do the same, however this may be an area to area decision. I would suspect that it is an option they have considered and so may impliment if the situation requires. All the main roads will have heavy traffic, well I would expect them to. So on the day of it get going early, very early as you have 40 miles. It may be an easy trip and you get whereever early and are sat around, but at least you are there. Even if a bit bored and calling me an idiot. For the UK one some years ago I travelled down kind of ovwernight, arrived at about dawn and the car park I ended up in was over half full of people who had done the same. Meant I could make a coffee, eat something and have a kip. Not been said but getting out afterwards will also be a nightmare, likely worse. At least to get in people will be travelling over a slight spread of time. the get out bit is however all at once.
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