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Tommohawk

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About Tommohawk

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    The Quantocks, Somerset

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  1. EQ6 backlash

    No problem, glad it was helpful - couple of quick after-thoughts though which are perhaps obvious. Firstly if there's miles of backlash it may affect the pointing accuracy. Also when I suggested that deliberately mis-setting polar alignment might be helpful, this only works if autoguiding. If not autoguiding, PA is crucial. Also of course if PA is not accurate, pointing will be affected.
  2. Stellarium 0.16.0

    i installed in another directory because my StellariumScope setup always seems twitchy - however some settings still seemed to get overwritten. inevitably the start menu gets overwritten as does the shorcut - thats no biggie because you can just locate the original exe and start from there or make a new shorcut from the original exe. The start view and location was overwritten, which isnt too problematic. Maybe I missed a checkbox? The main problem for me is if the sensors and scope and EPs get lost - fortunately that didnt happen. Anyhow, FWIW I agree that objects / hints now seem to appear with use of the sliders according to their magnitude which is great! Great work Alex - thanks! BTW is there a proper place to put things on the wishlist?
  3. EQ6 backlash

    Probably more than a thousand! Here's my take on backlash but others have different views! I dont have an EQ6, mine's an HEQ5 but I think the same applies. Mechanically you can reduce backlash by adjusting the mount - the worm can be moved closer to the main gear but of course not too tight so that it seizes. Because the gears are never perfectly centred and also wear more in some places, you may find its loose in some areas and tight in others. I find the easiest way is to remove the intermediate gear to disconnect the motor so you can turn the worm through the entire 360 degrees manually and check for tight spots. You can also get a belt drive conversion which may help to reduce backlash in the intermediate gears. In my opinion, and I think I may be in a minority, backlash isn't the main problem - or even a problem at all! You can completely avoid backlash by being deliberately slightly imbalanced. The real issue is that the mount will only drive smoothly against the weight, not with the weight behind it. You can try this for yourself - if you remove the intermediate gear, set the mount so theres a slight imbalance and try manually driving the worm in either direction. One way, ie against the weight, it will be quite smooth; the other way will be more jerky. In RA all you need to do is make it "East Heavy" so the mount always drives against the greater weight of the scope or counterweight depending which side you're imaging. In theory you could have a mile of backlash and it wouldnt matter. Honest. DEC is a bit more of an issue, because it may need corrections in both directions. Again you can avoid backlash by a slight imbalance, but corrections may need to be in both directions so you can't be driving against the weight in both directions. In fact if you dont have perfect polar alignment its possible to ensure that youre always driving against the weight - but you have to figure out which way to do this, and i've never managed this! I will now be shot down in flames - you can make your own mind up!
  4. Stellarium 0.16.0

    Alex - I downloaded this but on install I get all sorts of virus warnings. I'm sure its OK, but just wondering why this is given I dont normally have a problem with Stellarium installers?
  5. Stellarium 0.16.0

    Cuivenion - you should find that version here BTW Alex I haven't tried this install yet, but is it standalone which I can install in another directory, or does it need to be installed on top of V16 ? I'm just wary of unsettling my stable version esp as it work well with Stellarium SCope
  6. Stellarium 0.16.0

    Do the hints/labels show if you zoom in more maybe? - See my comment above re PNs
  7. Stellarium 0.16.0

    Agreed the hint sliders work well - although I can slide them all the way up and planetary nebulae hints still don't show unless you zoom right in to the object. Seems a bit odd.
  8. Stellarium 0.16.0

    Following on from this, how do you know which DSOs should be showing? Should there be images for all catalogued objects?
  9. M16 and Veil...Double trouble...

    Agreed about the dual use of camera lenses - that said my Tamron 300mm is so heavy its a bit of a beast on the camera, and in practice I seldom it use other than for Astro. I was just thinking that the 350mm Star 71 isnt a million miles different from the 300mm camera lens, and I was curious to know if you felt the image quality was perceptibly better with the dedicated scope. Focusing must be easier I guess too.
  10. M16 and Veil...Double trouble...

    Yes, much better to my eye - just had a look at full size and that's really nice. BTW not sure how long you've had the WO, but how do you reckon it compares to your camera lens?
  11. M16 and Veil...Double trouble...

    Hi Tim - that's very nice and as you say its all progress! I think there might be a bit more blue in there though? Last year you did a tweak on my Veil effort which really brought that out. Also I seem to remember last year you were using ISO1600 - I wondered why the switch to ISO800? M16 is great too - the background looks really good.
  12. Veil bi colour 4 pane mosaic

    Very nice - lots of fine detail and a very natural look to it. Just one question.. where the heck are you finding all the clear skies??
  13. Saturn 24th July

    Thanks Pete. I wondered afterwards if I might have done well to add some Lum data, if only because I might get a higher frame rate. Bit late now, but any thoughts on this?
  14. Will be interested to see how you get on with the guider set up - keep us posted please! Re the HEQ5 for air travel - I have HEQ5 and looked at this but you are really going to rack up some weight. 9.9kg for the head and 5.6 for the tripod. Also its surprising how long the legs are. I have a pretty large case - cant remember the dimensions - but it wouldn't go in. I'd have thought the HEQ5 is overkill for the Nikon lens, though of course it would then be more accommodating for a bigger scope. For transporting by car within the UK I guess the weight isnt a problem and if you already have an HEQ5 then why not. BTW I was thinking of shortening the HEQ5 legs a bit which should work OK (and lighten them a bit) to fit in a hold case for use with the EQ3 pro which currently has the standard ally tripod - a bit more stable.
  15. Your setup looks good! Looking at MattJenko's setup you probably could use a long dovetail and put the guider under - would need to be short though or balance might be awkward. Or use a dual side by side mount. I got the ADM version and its really solid - but it weighs 1.4kg so for airline travel a bit of a lump. There are other versions that are lighter. But if you have an F2.8 lens you'll be faster that MattJ's setup, and he's not guided. That said if you want to do NB or do v faint targets you may want longer than 30s subs. BTW since this thread started I got a chance to try my EQ3 pro +300mm Tamron + DSLR with 60mm BST guider. Works well, but a lot to travel with - had to get 20kg hold case and rammed cabin bag. Have you decided on mount yet?
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