Original 1960 RCW Catalog/atlas!

[Lognic04 (Logan)]

Hi all,
I recently was up in Canberra and mount Stromlo and picked up a original 1960 published RCW atlas with stunningly deep for 50s era halpha photos taken with an 8 inch f1 astrograph! It also makes me think, howcome we have become less adventurous with scopes? Now everything is an f5 8 inch newt or 80mm frac or 8 inch screen on an eq6 etc. What happened? Nitpicking over star shapes or something?

Anyways, the atlas is amazing with 5 full page a3 mosaics with 18 panels spanning half the southern Milky way!!!

[Wavytone]

Regarding the atlas, I recall seeing a modern attempt circa 1990 to recreate a similar one using images taken with a 35mm camera and filters from the Blue Mountains. It was a fairly heroic effort on the part of two amateurs.

As one who was a scholar at Stromlo, from memory another similar atlas was compiled from plates taken with the camera atop the Oddie refractor. That camera was actually an aerial photography lens of WWII vintage - roughly 20" focal length and f/5 and the plateholder took quarter plates (4" x 5").

Where the 8” f/1 schmidt went.. unknown.. but it would have been a royal pain to cut the film for it and load the film holder all in the dark.

Someone in that era also donated a Perkin Elmer Minitrack Optical Tracking System (MOTS) to the Canberra Astro Society. The MOTS was based on an aerial camera - 8" aperture f/5 (1 meter focal length) designed to cover full-size 8"x 10" glass plates (!) and its purpose was to image satellites in order to measure their orbits, in the early days of the space race (1960 onwards). The snag with both the camera on the Oddie and the MOTS is that (a) neither were particularly well corrected chromatically, meaning you had to use a monochromatic colour filter t get anything resembling a half-respectable image, (b) optically they were not particularly sharp - nowhere near diffraction limited - so the images from them did not tolerate signifiant enlargement. Attempts to visually observe images with an eyepiece through the MOTS showed the images were fairly atrocious and nothing like what any of us would think of as useful, visually. Both lacked modern antireflection coatings so even with an air-spaced triplet, the transmission was below 50% simply because of the losses at each air-glass surface.

I'm not sure if you are aware of this, but aerial cameras imaging onto glass plates are from an era when the prints were made as contact prints - ie you placed the plate on the paper emulsion-side down so the print is a 1:1 copy - not enlarged.

Another aspect of that atlas is compiling the mosaics was an art in itself, and frankly only possible with a permanent setup where the camera once focussed could be left in that state for months while the plates were taken, probably no more than 1 or 2 per night, and using contact printing to ensure the prints were all at exactly the same scale.

Depending on what was available from the store, you could either use a box of Kodak plates, or if keen, you could mix the chemicals and make the emulsion and coat the plates yourself. The Oddie also had a darkroom beside the scope - after exposure you could develop it then and there.

I had used that camera few times out of curiosity, though rapidly realised that photographically it was quite a slow combination - shooting 35mm film through my 8" Newtonian atop the Oddie gave far better results (sharper and deeper) though obviously over a much smaller field.

Today however the scopes we use are designed for tiny, tiny sensors - which requires diffraction-limited performance over a small field of view. However, the images from these will stand huge enlargements - think of the size of say a 27" computer monitor vs the sensor size.

So unless you have a box of 8" x 10" plates somewhere or a box of quarter plates, these cameras are now useless junk.

[RyanJones]

A fantastic find Logan.

Re: Less adventurous with scopes ? I guess when there are so many good quality OTAs and digital receivers, we are no longer satisfied with simply capturing an object 10 million light years away but we want it to be asthetically perfect too. It does make me wonder sometimes if astronomers and more specifically astrophotographers have forgotten some of the wonder of what we are looking at. I guess to a greater extent we as a human race have lost a lot of the wonder of our surroundings because of the technology we have. I wonder how many of us stop and think about the physics going on to be able to transmit our thoughts between each other on this very forum. On an even bigger scale, how we as humans evolved to the point we have to even be here sharing these thoughts. I digress. I think the people who created that beautiful atlas had greater drive to do things that they were told couldn't be done or to discover things that didn't exist. Their minds weren't clouded by the perfect star but the sheer wonder of stars they were discovering.

[Wilso]

Nice one!

Talking about cameras
I was listening to a pod cast last week about the first spy satellites and the camera and logistics involved getting the film back to earth.
The special cameras had to be pre loaded with 30 miles of film and focused before launch. A frame rate of 71 inches a second! automatically loaded into an escape pod (the film had to be protected from heat from re entry ) parachuted to earth and caught mid air by plane.
The talk involved the original man that designed the cameras.

Space boffins (spy satellite special)

Excellent pod cast.

[Lognic04 (Logan)]

Wow wavytone, really interesting!!!!
I took a photo of the first page with info for you to see.
Ryan I think I agree, people forget the significance of what they are imaging!!!
Interesting Darren!