All the flexed mirrors I've looked through and admittedly not very many have had problems with astigmatism. It seems to me that it's simply trouble that you...
the minimum I could said is that is a good bad side of flex analyssing very good but now like I make on any new ideal analyse the good side put on 2 colons...
For anyone who is building or thinking about building a longer focus Newtonian I currently have two finished mirrors available. An 8" F/7.1 (full thickness...
Tony, I have checked out your web site and approved your post even though you are a new member to ATM_FREE. I just know someone is going to ask about your...
Will do and thanks for the support! Tony ... From: "Ken Hunter" <atm_ken_hunter@...> To: <atm_free@yahoogroups.com> Sent: Thursday, November 01, 2007...
I see at tv somebody try to do fire whit wood and so all kind of setup the curuous one is whit some kind of big lent very curve to be survive to the hot sun of...
Hi Jacques, I’ve seen smoke made with an ice lens once, and I have made an ice magnifier once (for a high school science project) was quite messy doing this...
Tom, I took some photos of the slide focuser and discovered that the tall eyepiece holder unscrews leaving a shorter section. That was meant to take something...
I uploaded the pics for anyone who might find them interesting. I think the slide could easily be motorized if driven by a fine- threaded rod and nuts on the...
I've been working with some astrograph designs and am finding that with today's DSLRs it really helps to get rid of the focuser all together, mounting the...
Hello all I have a Hanimex 7 x 50 bino. I find that lately the image is not clear and there is a diffuse background present spcially around bright objects. I...
Tony, In principle a very small positioning error or in angle at the primary is magnified greatly at the secondary. The best thing to move is the DSLR. How...
Well that doesn't help me, all I want between the DSLR body and the tube is a t-ring. I could move the entire camera mount and secondary together ala Comet...
... questions. ... than a "hard ... Calculations show they can be as good as < 1/125 wave P-V according to various people I've talked to. I've only looked...
... over a ... was ... was a ... If you could create a slight vacum inside you would get a very nice curve. More pressure = more curve. Food for Thought, Mitch...
I agree with that. Flexing a sphere into a parabola is a nice trick but I don't think it's a practical replacment for a well figured parabolic surface. Once...
I made that whit alluminium for sheap mirror you hust full the jar whit water and add a valve after open the vave to get the riaght focal but try to still very...
If I had to do it again I would go the vacuum pan route, but this was 15years ago now, and no-one really had any idea of what I intended to do. Actually the...
The Clement Focuser should do the job of moving the primary mirror with the precision required. Moving the mirror to focus should be no more difficult than...
With a low f# astrograph you will need a coma corrector, if this has enough back focus it will project the image back into the DSLR. For example the HN design...
Hi Tom, I'm working on a flat-field Schmidt Camera design so there's no coma correcror, just a field flattener....... Tony ... From: "tomofreno2000"...
from my study of the formaula is like this y = a + bx + cx^2. parabole y = a/2 * (e^(x/a) + e^(-x/a chainette and you can see the curve fit in file section ...
last addition in french http://www.mathcurve.com/courbes2d/chainette/chainette.shtml a study of matematical way jack 47'n 71'O ... lens, not ... think it...
Tony A brilliant idea. How about a helical mechanism to move the primary mirror and a nice little stepper motor attached to a worm wheel to motorise the...
Actually those are all good ideas and would be very nice to have on a larger version of what I have in mind. Probably overkill though for the small 4" to 6"...
Hmmm. I didn't pay much attention to this at first, but now you've got me thinking seriously about it Tony. I'm gathering materials to make a 10" f/4.1-4.2...
Exactly, there area lot of advantages once you start to really look at it. It's funny but if you can find a drawing of Newton's original "Newtonian" it also...
... clear ... I ... The problem is your environment or climate. It will surely cost you more to have it cleaned and collimated than to buy a new pair. Don't ...
Why not put the camera body and the diagonal on a moving sled? My two paisa Ulhas ... tube is ... together ala ... Hell, almost ... primary ... the ... one? I ...
