4" instrument, a serious planetary scope it is!

Before you guys with the 5", 6", and larger cast the first aperture stone, please here me out....

I was catching up on my reading of the Oct. issue of S&T when I came across a most interesting article about astronomy in Mexico. Then, my 4-inch short sighted eyes caught something. "A keen planetary observer, [Francisco Javier] Escalente [1887-1972] spent 55 years observing Mars [my favorite planet] from his home in Mexico City, using a 4-inch Zeiss f/21 refractor. In 1960, he and fellow member
Elpidio Lopez wrote a landmark 620-page book on the red planet, filled with numerous highly detailed drawings that they had made at the eyepiece". [S&T Oct 2002]

Boy, was it an astro-orchestra to the ears of my 4" TV-102 Light Cup. The 4-inch instrument is indeed a serious planetary instrument! I can only imagine the wealth of material in the elbow busting weight of his 620-page book! Surely, if the 4-inch weren't serious, it couldn't have produce so much data. Also, he was honored by the
International Astronomical Union by having a 49-mile crater situated along the Martial equator at longitude 245d christened with his name.

Now, I have escalated my quest to find out more about this
fascinating astronomer. Unfortunately, Google search turns up nothing. Does anyone have any more info? Anyone else knows who used a 4" instrument to study and publish papers on the planets in the past? Well, the next time I'm in Mexico, I'd sure visit the library!

So let us all who owns the small telescopes (4" refractor, 4" MCT, 4.5" Newt, 5" SCT, 5" MCT, etc.) not forget to
"seriously" observe the red planet next year.

Ron B[ee]
PS Feliz aniversario, SAM y felices Fiesta Patrias!

From what I hear from optical designers and from those that have been involved with making refractor lenses its much easier to make a really good 4" lens and that you can achieve better optical perfection with this size. Once you get into a 5" lens it get harger to optain a really good figure and when going to 6" even harder still. Its almost like were a 7 to 9 inch reflector is the best size for really good planetary if made well. MCT's and SCT's are the same way 5 to 6 inch scopes work very well but as size increases so does that optcial variant. It all boiles down to how much time a company is willing to spend on making these optics and still be profitable.

Ron
I was able to do some excellent drawings with a 100 mm f 10 Zeiss refractor the last three oppositions.

The colour balance and contrast in these scopes is excellent for Mars. Contrast per image brightness is as goos as it gets and I guess Zeiss made the best objectives available ib their day.

They certainly deliver the goods as good as one can expect for a modest aperture. I've yet to see C 8's and homemade dobsonians do as well but I will admit I have'nt spent all that long at their eyepieces. Too busy enjoying the Zeiss views.

And while the 100 mm size will do well with an excellent objective(like your TV102) a 5 inch refractor aperture if made well will do even better.

Kevin Barker

Kevin

I know the term "serious" is used a lot wrt scopes, but it really isn't the scope that is or isn't "serious", it's the observer. To a "serious" observer, the scope is just a tool. If you've got a job to do and need to tighten a nut, you might reach for an adjustable wrench near you on the counter top, but you probably wouldn't worry much about whether it was the optimally-sized adjustable wrench as long as it was big enough to tighten that particular nut.
--
Mike

After lurking on several boards with this interesting thread, just wanted to point out that Fred Price's "The Planet Observer's Handbook" supports the idea that 4" of quality refractor can do serious planetary work. Today's 4" apo instruments would have seemed magical to the 19th century observer.

I'd like to thank everyone for contributing to this thread. At first, I thought it was a no-brainer post; boy, I've learned so many things from this thread! I can't even begin to tell you guys how much I appreciate your participation.

I promise to let you know if I hear back about Escalente. The author of the S&T article was kind enough to reply to a nobody like me. Escalente was actually his professor and his teacher! The scope was a 110mm Zeiss refractor (not exactly 4-inch ;-). The book has probably been long out of print, but I got an invitation to look at his copy if I'm in Mexico City ;-)! Super. Though I won't be there anytime soon, I promise a follow up post after I get there, umm,
maybe during Mars opposition as it'd surely be better position down there than here, wouldn't you say?

Ron B[ee]