Stub Mandrel

:-) Hope to gaze into the depths of your mirror one day!

You could sell that to the Tate Modern.

Thanks, I already found the strip down thread. I do plan to do that. My EQ3 tripod is partly sand filled, braced with bits of studding and one leg aluminium welded solid! I replaced the top with the top of a Bresser EQ1 type tripod/mount and have a pretty good mount for small scopes.

The forum software is excellent, as an admin on another forum I am deeply jealous.

Yes, I agree, I'm getting 80 second subs from my EQ3 with the new style polarscope, and I reckon I can easily get up to 2 minutes, I just haven't tried yet.

That's a brilliant way to encourage beginners, Tim! It has to encourage people especially knowing it's the same scope. Perhaps we should have a before and after my first year thread to cover how much your first faltering steps can improve. it cost me about £210 to go between these two shots (OK they are planets not DSOs: Perhaps we should have a specific before and after thread where people give an idea of the time between the two images and a rough idea of budget and equipment, focusing on the progress they made at the beginning, rather than when they could afford expensive gear?

Thanks. I sometimes think people are scared off when they cost up an 'imaging' setup, so I think it's important they realise what can be done with basic gear.

Thanks, you have a PM<, though its shame to benefit from your misfortune.

Last night I took 35 80 second subs using my camera with a 400mm tele lens mounted next to a 70 x700mm scope on my EQ3 mount on an EQ5 tripod. Quick and dirty aligned using the polar scope, no drift align. Over 1 hour 7 minutes, the images offset by a total of 32 pixels vertical, 8 pixels horizontal, but almost all the horizontal drift was on the first two images (presumably taking up the backlash). So the real drift was about 32 pixels or 1 pixel every 2 minutes. Looking at the subs I thought I could spot a few where there was more noticeable movement between subs - then I checked and these 'jumps' were where I had dropped subs because of aeroplane trails, causing nearer to a 2-pixel jump instead of one. There didn't seem to be any of the jumps I would have expected if there was significant periodic error in the worm wheel. What was most striking is that every single sub showed nice round stars - as would be expected if the camera had strayed less than 0.5 pixels either side of the mean position. I won't pretend that these results are good enough for long subs, but they do show that an EQ3 mount properly balanced and aligned with a bit of care on a solid tripod is capable of long enough exposures for imaging DSOs. It also suggests to me that it will be worth me upgrading to autoguiding before upgrading my mount - which is against conventional wisdom. It also lends support to my suspicion that the weakness in the normal EQ3 setup is the aluminium tripod not the mount. Something I want to try is taking long, unguided, wide field exposures. With a 28mm lens the tracking errors should be under a pixel even at 10 minutes exposure. This should be also be a way to see if there is significant periodic error.

Has anyone in this thread got an unwanted LP1 filter that could be retro-fitted into my Canon D10 to save me from bloated stars?

Ah, I don't now how the glass is supported on the Sony chips. The Canon ones have a significant gap between coverglass and sensor.

Ok, here's another idea. Get a single point diamond wheel dresser (about £4 on the bay, a fraction of the cost of a scriber). Scribe four lines around the hole you need in the chip, then VERY GENTLY two more across the diagonals (optional). Apply tape. Press on centre of the glass with thumb or tap with tail-end of dresser. The centre should break out with no need to use heat. I used my wheel dresser to allow me to break a 6-foot mirror in two so that I could tip it a few weeks ago.

Just a suggestion - the hazard is shattering the glass cover and shards breaking the chip wires, is it not? Why not put a slip of high-strength tape over the glass before trying to prise it loose. That might stop any chip large enough to cause damage coming free.

Add a head strap and they would make a great SteamPunk accessory

Ok, I get it - you are the human fly and have compound eyes...

> The guidescope I'm working on (not pictured) is an old 500mm telephoto. Interesting, I'm thinking of making a t-mount fitting focuser, if tehre's enough room, it would be fun to make my 500mm f8 lens into a very compact grab'n'go maksutov

It's amazing what you can get away with up to 20MHz+, and there are times I suspect the 10D runs at nearer 20 KHz... anyway nothing to lose by trying ;-)

If conductivity was the requirement, they'd be made of silver not gold, its so they are easier to attach and don't corrode. The silver paint has ~ 1/400 the conductivity of gold but as the cross-sectional area will be many times the diameter of the wire and current path will be very short, I don't imagine the difference would be significant (possibly detectable by the people who use gold plated battery clamps for their in-car HI-FI). Any minor difference should be compensated for by control frames. I think its actually doing it that's the challenge.

That's pretty much what I had in mind. CPC do one you can wash off if it goes wrong.

If we can work out a wire-reattaching method... I now have a 10D sensor to practice on :-(

Courageous choice. You've avoided the 'owe it to our lads' fallacy! Keep up the updates!

As a spectacle wearer I can vouch for the fact that the eye/brain combination is very good at doing on-the-fly RGB alignment. It can be fooled, illuminated TESCO signs in red and blue and the HSBC logo on a computer screen both show movement of the two coloured parts when I move my head - in fact the red spelling wiggle under TESCO moves side to side as I shake my head! But when the colours are overlaid, the eye correct (e.g. the word TESCO in white doesn't split into RGB except at the extreme edge of my vision, even though the red bit must be moving as much as the wiggle!)

Personally I find the Moonraker overdone, the understated Zeiss says quality that has gone into the optics, not the bling.

Great pic! I was able to find the moons in photo paint. You might try something like this: Create a circular mask around the planet (it can have a wide margin) Invert the mask Stretch the histogram until the moons appear, the background will become grey move the black point until the background matches that around the planet. You can tweak the histogram. Clear the mask For images where the moons are more obvious, you can just mask around them and use the same technique. I did this to bring out Mars and Regulus on my shots of this morning's conjunction.

Don't rush. You've got all the time in the world.