Re: ISS - 1st attempt to capture overpass streak
Kurt, I bought the Zenitar 16mm f/2.8 fisheye a few years ago, but (time to crow a bit) I only paid $75 on eBay, for a brand-new unit. Do you know of a translation of the manual somewhere, perhaps? I'd love to accompany you next time you shoot and try to duplicate your shots, if you're up for the company.
From: Canopus56 <canopus56@yahoo.com>
I used a recently purchased low-end Zenitar 16mm/2.8 fisheye lens. I principally purchased this lens for making NELM sky study photos. I wanted to keep the cost down - it's $125 instead the of $375 for a mid-low end Pentax lens or $500-1000 for professional lenses.
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Aloha Chuck The Zenitar is an OK lens to play with and you are right, the big $$ Fisheye lenses are better but not by much when it comes to low light-astrophotography. Where the better lenses excel is in edge sharpness. I just posted an image from my experimental 4X5 AllSkyCam http://www.utahastronomy.com/rob/eAllSkyCam_8_12_05 and it is made with an inexpensive Russian made lens for the 6X6 Pentacon cameras and exhibits coma flaring along the edge of the image circle. The lens has a sweet spot in the center but along the edges, no comment. I'm still having fun capturing a big chunk of the sky .................. Aloha from WINDY Maui Rob
Hi Rob, Can you get rid of some of the coma by closing the lens down a bit (ie. larger f/number)? Patrick Rob Ratkowski wrote:
Aloha Chuck
The Zenitar is an OK lens to play with and you are right, the big $$ Fisheye lenses are better but not by much when it comes to low light-astrophotography. Where the better lenses excel is in edge sharpness. I just posted an image from my experimental 4X5 AllSkyCam http://www.utahastronomy.com/rob/eAllSkyCam_8_12_05 and it is made with an inexpensive Russian made lens for the 6X6 Pentacon cameras and exhibits coma flaring along the edge of the image circle. The lens has a sweet spot in the center but along the edges, no comment. I'm still having fun capturing a big chunk of the sky ..................
Aloha from WINDY Maui Rob
Hi Patrick I can remove the coma by stopping down, problem is that 4X5 sheet film has a top ISO of 100 and even w/ a 1 1/2 stop push (320 IS)) exposure is 90 minutes at F4 and at the time I was using a Celestron CG5 GEM. I just got my G11 today and I am planning a trip up Haleakala this weekend and may do a 3 hr exposure w/ the AllSkyCam. It's all experimental now, next step will be to hook up my 45mm Pentax SMC on the camera and also try a Schneider 58mm XL ( corrected wide angle for 4X5) I'm trying to get enough 'across the image' sharpness to make a 5' x 5' print. The idea is that the viewer approaches the photo and gets immersed in an eye filling view of the night sky, something that an average person never experiences. I think it will be a pretty nice presentation. aloha Rob
--- Rob Ratkowski <ratkwski@hawaii.rr.com> wrote: <snip> > The Zenitar is an OK lens to play
with . . . I just posted an image from my experimental 4X5 AllSkyCam http://www.utahastronomy.com/rob/eAllSkyCam_8_12_05 and it is made with an inexpensive Russian made lens
for the 6X6 Pentacon cameras . . .
Rob, Do you have any rough plans or a general optical layout for your AllSkyCam? For my initial "play" experiments and to get the 360 deg sky view, I was planning on taking a view photos at 60 degree azimuth angles and then digitally synthesizing them into a circular image. Nice image in a dark sky in Hawaii. - Canopus56 (Kurt) __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
Aloha Kurt The AllSkyCam is my 3rd version of this idea. It all started when I saw a fellow on line build an ultra-wide medium format camera by adapting pieces from several camera, at the same time I was in contact w/ Dennis Anderson (Auroradude.com) in Alaska and he talked about his 4x5 Toyo adapted w/ a 30mm Arsat for near 180 hemispheric photos. I then liked the idea, bought the Arsat lens on eBay and took apart my Sinar P to use some pieces for a test. The format frames were attached to a 4X5 piece of aluminum, I cut a bellows down to 3-4 pleats and began to play and learned that getting exact focus w/ a non focusing camera is not the way to go. I then bought (again eBay) a Sinar Alpina, modified the standards and mounted the whole affair onto the 6" extension rail where I have focus and a nice solid package. This camera mounts onto a Celestron CG5 drive and I have been having fun and non successes ever since. No plans, just some photos and a whole flock of fun ................... Aloha Rob
--- Rob Ratkowski <ratkwski@hawaii.rr.com> wrote: Thanks for the details - the extension rail - good idea. - Canopus56(Kurt) __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
--- Rob Ratkowski <ratkwski@hawaii.rr.com> wrote:
The AllSkyCam is my 3rd version of this idea. . . . I then bought (again eBay) a Sinar Alpina, modified the standards and mounted the whole affair onto the 6" extension rail where I have focus and a nice solid package.
Rob, what's the final image size on the negative? - Canopus56(Kurt) __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
Hi Kurt Image size is a 3 1/2" circle. If I could find a CCD that's 4" x 4" I could stop down and eliminate some/most of the coma in the image. Still WINDY on Maui Rob
--- Chuck Hards <chuckhards@yahoo.com> wrote:
Kurt, I bought the Zenitar 16mm f/2.8 fisheye a few years ago, but (time to crow a bit) I only paid $75 on eBay, for a brand-new unit. Back when gas was 95 cents a gallon?
Do you know of a translation of the manual somewhere, perhaps? The Russian cryllic manual is a hoot. The Russian only manual is a drawback to the Zenitar.
I'd love to accompany you next time you shoot and try to duplicate your shots, if you're up for the company.
You're always welcome. Of few remaining overflight passes, the 17th looks the most promising, although it is a full moon night: 9/17/2005 Saturday Appears      20h46m30s   5.0m  az:302.1d WNW Transit      20h51m23s  -1.1m  az:220.7d SW  h:48.4d              dist:461.4km  alt:353.2km Sunset 19:34 Civil Twi 20:02 Astro Twi 21:07 Full Moon Disappears   20h52m25s  -1.0m  az:164.5d SSE  h:30.8d I'll send you a reminder email a few days before. I'll probably also try Friday, 9/16/ 2005: 9/16/2005 Friday Appears      20h20m42s   4.4m  az:309.6d  NW Transit      20h25m37s  -1.4m  az: 32.0d NNE  h:45.7d              dist:481.7km  alt:354.2km Sunset 19:36 Civil Twi 20:03 Astro Twi 21:09 Disappears   20h27m24s  -0.4m  az: 99.5d   E  h:19.1d The civil twilight sky may be too bright during this overpass, but the ISS track takes it within 20 degrees of the near full Moon rising in the east. That may be close enough to capture the track and the Moon in one frame with a superwide lens. See www.calsky.com for the ISS track detail on that night. - Canopus56(Kurt) __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
participants (4)
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Canopus56 -
Chuck Hards -
Patrick Wiggins -
Rob Ratkowski