Hi,
derzeit geben Venus und Merkur am Morgenhimmel ein schönes Paar ab. Am 29. sind sie am dichtesten zusammen.
Hab übrigens noch etwas bei Ebay gestöbert. Es gibt dort ein 0.75/50mm Objektiv für derzeit 9 DM.
http://cgi.ebay.de/aw-cgi/eBayISAPI.dll ... 1287604247
Haken an der Sache. Die Bildebene liegt bei diesem Objektiv 2-3mm hinter der Linse. Außerdem hat das Teil einen Kratzer und ich weiß nicht, ob es auf Unendlich korrigiert ist. Objektive dieser Art sind zusammen mit Lichtverstärkern ganz gut einsetzbar. Auch Astrokameras wurden schon damit ausgestattet. Ich frag mich aber wie man den Film so nah an die Linse bekommt.
Grüße,
Mark
Venus/Merkur am Morgenhimmel
-
jan lameer
Re: Venus/Merkur am Morgenhimmel
Hi Mark!
I've had objectives like these in my hands and seen pics taken with them. In the Netherlands the going rate is about 100 guilders (DM 90).
Apart from the small distance of the last lens element to the film there is another problem: these lenses give only a small circular area of 25 mm or so on the negaytive.
Also focusing is very hard with 0,75 f/d.
Since you cannot focus with a mirror, you have to find the good focus through testig. When temperature changes, the focus also changes so you have to do tests with different temperatures.
The pics I saw were from the milky way without guiding. Lots of stars but not sharp. I suppose the lensdesign is only good for very short wavelengths, not really for photovisual wavelengths. Also, if I see how bad my 2,0 24 mm Nikkor performs with star images in the corners, I doubt if a 0,75 objective can give pleasing photographs.
There are some "dream" objectives: the 1,2/58 Noctilux aspherical Nikkor (only collectors have them) and the 1,4 24 mm aspherical Cannon. These are quite expensive though and for me buying film, and batteries has a higher priority than buying glass.
Until recently I had a 1,4 85 mm Nikkor, with which I could even photograph one of the satellites of the Andromeda nebula from a fixed tripod on 3200 ISO film. But I sold it as I never used it and having a heavy 1350 DM objective unused in the camerabag is a little silly.
Oh well, just some late night thoughts....
I've had objectives like these in my hands and seen pics taken with them. In the Netherlands the going rate is about 100 guilders (DM 90).
Apart from the small distance of the last lens element to the film there is another problem: these lenses give only a small circular area of 25 mm or so on the negaytive.
Also focusing is very hard with 0,75 f/d.
Since you cannot focus with a mirror, you have to find the good focus through testig. When temperature changes, the focus also changes so you have to do tests with different temperatures.
The pics I saw were from the milky way without guiding. Lots of stars but not sharp. I suppose the lensdesign is only good for very short wavelengths, not really for photovisual wavelengths. Also, if I see how bad my 2,0 24 mm Nikkor performs with star images in the corners, I doubt if a 0,75 objective can give pleasing photographs.
There are some "dream" objectives: the 1,2/58 Noctilux aspherical Nikkor (only collectors have them) and the 1,4 24 mm aspherical Cannon. These are quite expensive though and for me buying film, and batteries has a higher priority than buying glass.
Until recently I had a 1,4 85 mm Nikkor, with which I could even photograph one of the satellites of the Andromeda nebula from a fixed tripod on 3200 ISO film. But I sold it as I never used it and having a heavy 1350 DM objective unused in the camerabag is a little silly.
Oh well, just some late night thoughts....
-
Mark (Rottal/Niederbayern)
Rayxar
Hi Jan,
thanks for your additional information. I try to get this lens from Ebay. I`m not sure what to do with it, but I have in thought to combine it with a cheap generation 1+ image intensifier to make some attempts to film aurora. A red filter may help in front of the lens to enhange contrast.
Here are some Rayxar astro pics:
http://www.sterrenkunde.nl/jwg/universu ... kodak.html
Best,
Mark
> Hi Mark!
> I've had objectives like these in my hands and seen pics taken
> with them. In the Netherlands the going rate is about 100
> guilders (DM 90).
> Apart from the small distance of the last lens element to the
> film there is another problem: these lenses give only a small
> circular area of 25 mm or so on the negaytive.
> Also focusing is very hard with 0,75 f/d.
> Since you cannot focus with a mirror, you have to find the good
> focus through testig. When temperature changes, the focus also
> changes so you have to do tests with different temperatures.
> The pics I saw were from the milky way without guiding. Lots of
> stars but not sharp. I suppose the lensdesign is only good for
> very short wavelengths, not really for photovisual wavelengths.
> Also, if I see how bad my 2,0 24 mm Nikkor performs with star
> images in the corners, I doubt if a 0,75 objective can give
> pleasing photographs.
> There are some "dream" objectives: the 1,2/58 Noctilux
> aspherical Nikkor (only collectors have them) and the 1,4 24 mm
> aspherical Cannon. These are quite expensive though and for me
> buying film, and batteries has a higher priority than buying
> glass.
> Until recently I had a 1,4 85 mm Nikkor, with which I could even
> photograph one of the satellites of the Andromeda nebula from a
> fixed tripod on 3200 ISO film. But I sold it as I never used it
> and having a heavy 1350 DM objective unused in the camerabag is
> a little silly.
> Oh well, just some late night thoughts....
thanks for your additional information. I try to get this lens from Ebay. I`m not sure what to do with it, but I have in thought to combine it with a cheap generation 1+ image intensifier to make some attempts to film aurora. A red filter may help in front of the lens to enhange contrast.
Here are some Rayxar astro pics:
http://www.sterrenkunde.nl/jwg/universu ... kodak.html
Best,
Mark
> Hi Mark!
> I've had objectives like these in my hands and seen pics taken
> with them. In the Netherlands the going rate is about 100
> guilders (DM 90).
> Apart from the small distance of the last lens element to the
> film there is another problem: these lenses give only a small
> circular area of 25 mm or so on the negaytive.
> Also focusing is very hard with 0,75 f/d.
> Since you cannot focus with a mirror, you have to find the good
> focus through testig. When temperature changes, the focus also
> changes so you have to do tests with different temperatures.
> The pics I saw were from the milky way without guiding. Lots of
> stars but not sharp. I suppose the lensdesign is only good for
> very short wavelengths, not really for photovisual wavelengths.
> Also, if I see how bad my 2,0 24 mm Nikkor performs with star
> images in the corners, I doubt if a 0,75 objective can give
> pleasing photographs.
> There are some "dream" objectives: the 1,2/58 Noctilux
> aspherical Nikkor (only collectors have them) and the 1,4 24 mm
> aspherical Cannon. These are quite expensive though and for me
> buying film, and batteries has a higher priority than buying
> glass.
> Until recently I had a 1,4 85 mm Nikkor, with which I could even
> photograph one of the satellites of the Andromeda nebula from a
> fixed tripod on 3200 ISO film. But I sold it as I never used it
> and having a heavy 1350 DM objective unused in the camerabag is
> a little silly.
> Oh well, just some late night thoughts....
-
jan lameer
Re: Rayxar
> Hi Mark!
If you get it cheap, why not. But a 65 mm fl with a 25 mm (or less) circular field is a telelens. I think comparable to a 65 mm lens on a 16 mm filmcamera. For those small formats, a 10 mm is a wide angle.
Anyway, it will be a nice thing to play with. Perhaps it will be a good ocular for a telescope?
As I remember it has a triple thread in the back...
If you get it cheap, why not. But a 65 mm fl with a 25 mm (or less) circular field is a telelens. I think comparable to a 65 mm lens on a 16 mm filmcamera. For those small formats, a 10 mm is a wide angle.
Anyway, it will be a nice thing to play with. Perhaps it will be a good ocular for a telescope?
As I remember it has a triple thread in the back...
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