I was wandering if it would be feasible to print the polar finder reticle on plastic foil..
So I produced the Autocad file, the only thing needed is adequate laser printer.
It should have >1000dpi.. Anybody could help me here?
The other option I think may work is pen plotter (they have 1mil resolution, which is 1000dpi) .. I have it so I will try to modify one standard pen into a scribbling tool, and then will try it on plastic foil..
You have to know how big to print it so it will be on the same scale as the finder image at the focal point of the finder eyepiece image.
You could establish the scale by using a two star separation and through trial an error set the correct scale for the reticle.
Hi Chris,
Thanks for suggestions :-)
The scale is not my problem, though.. rather it is the quality of print.
The reticle can have elongated markings for Octans asterism, so even 20% error in scale would not be really a problem.
20 years ago I would solve the quality issue easily - I would simply take a photo of the reticle model (drawn with black ink on white paper), using classical film camera loaded with graphic film, developed it in my bathroom and make a contact copy from it. All for couple of bucks and very little effort.
Today, with all those new technologies available, something essentially trivial like this is not possible !!! Or, it is actually possible, but restrictively expensive...
Yes. but my printer (epson ink jet) does not produce fine enough printout.
To the eye it looks so-so, but through eyepiece it is terrible.
On the other hand, I only need something to indicate the position of those couple of stars..
Hi Bojan,
We have a Canon iRC5180 Imagerunner laser printer at work, which does 1200dpi. Is there something I can try for you?
Oh, and I have overhead transparency sheets also.
20 years ago I would solve the quality issue easily - I would simply take a photo of the reticle model (drawn with black ink on white paper), using classical film camera loaded with graphic film, developed it in my bathroom and make a contact copy from it. All for couple of bucks and very little effort.
Today, with all those new technologies available, something essentially trivial like this is not possible !!!
I think your idea of essentially trivial and mine are somewhat different
I would guess that the best answer still lies in film though, maybe time to resurect that old hobby?!
I think your idea of essentially trivial and mine are somewhat different
I would guess that the best answer still lies in film though, maybe time to resurect that old hobby?!
I also think the film would be the best... but where to get developer, fixer... Film is still available from some obscure factories in eastern Europe I guess..
If I go out and try to buy those chemicals, I may even be arrested for manufacturing drugs or explosives
Perhaps the remark regarding HF acid was flippant. At the risk of seeming devoid of humour I would caution you against the use of that particular acid. I use it every day in a laboratory setting and believe me it can severely incapacitate you, even causing death. Full fume cupboard, poly materials, protective clothing are just the start. The fluid is horrendous, causing extreme necrosis and gangrene (not to mention pain) and the fumes can do untold damage to lung and eye tissues. Stick to printing film.
Cheers
Ian
Ian, thanks for a warning.
The film is what I intend to use.
I do not have much experience with HF (some from Grammar school, a long time ago), but I know it is VERY dangerous to handle.
And film, despite being not easy to find these days, will produce neat results, as I was using it a lot in the past for variety of applications (when I get some, that is).
In the meantime I am using what I have - Northern-style reticle with the help of CdC.
Well, after some time spend in unsuccessful attempts to find the graphical film, I tried with printing on foil for overhead projections.. just to test the size and general concept.
The results are not that great from the aesthetic point of view, but the graticule is actually very useful :-)
So I decided to post the pdf file here, in hope somebody may want to use it too.. the file should be printed on 1:1 scale, with maximum resolution the printer can offer (this file is produced with 4000dpi), the graticule itself should be cut out with scissors. The printing side should be mounted on top (closer to the eye), after original glass (for Northern hemisphere) is removed from holder.
Also attached is the crop from the test shot (200%), 10 minutes exposure with 135mm lens (ISO100, Scorpius region), some drift is visible on it, but this only means the alignment is OK for shorter lenses and/or exposures up to 2 minutes.. more than enough for acceptable wide angle photos (I usually take 1 minute at F5.6 maximum.. before LP kicks in).
!!! Or, it is actually possible, but restrictively expensive...
