
TeleGizmos Finder Covers
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Two new accessory covers from TeleGizmos: useful items or
just "gadgets?"
I am sure
every Red Dot Finder user sooner or later experiences this malady. You are
star-hoppin' happily along when your RDF suddenly winks out. You think you
just ran down your thirtieth battery. Instead you discover that the finder's
window
is totally covered in dew. Solutions to this problem were tossed about on a
Yahoo Group when word fell upon the ears, (or eyes) of Bob Pitney, owner and
founder of TeleGizmos. Bob makes high quality fitted covers that have saved
many a telescope and mount from the ravages of Nature. He just recently introduced
two new "downsized" covers to protect your finder scopes from dust and
moisture. Do these two new covers really do the job? Or are they just "gadgets"?
The idea
of a cover for an RDF makes sense; after all, you probably spend only a minute
or two looking through your finder during an observing session that may last
for hours. Why not cover the RDF to keep it clean and dry while you are not
using it? Unlike other TeleGizmos covers, it is designed without a drawstring
and to have a slightly loose fit so that you can take the cover on and off
without disturbing the alignment of your RDF. Will it actually keep off the
dew? I tested this little cover several times under observing conditions where
the telescope dewed over either while outside, or when I carried it inside and
it dew over from the warm moist indoor air. I determined that while it will not
keep the dew off forever, it does indeed retard the formation of dew on the
RDF's window.
"But
wait," you might say. "Isn't it cheaper and easier just to make your own little
dew shield?" I had actually made a
dew shield several months ago to target my dewing problem. So, which was more
effective? Well, here's the "head to head" (or "cover to cover.") Appearance:
okay, so I'm no artist. For construction, fit and finish, the TeleGizmo wins
hands down. Cost: it's
definitely cheaper to make your own, out of stock model plastic (as I did)
or card board, or perhaps even aluminum foil. The RDF cover, however, currently
costs less than $5.00. So, in my opinion, cost is not much of an issue. Still,
that point goes to the home-made unit. Performance: after using my home-made
dew shield for two months and the TG cover for a few weeks, I determined that
both performed more or less equally well. I still had dewing problems with
both
systems, but much less frequently, even when everything else had already dewed
over.
The next product from the TeleGizmos laboratory is the
cover that fits you optical finder scope. This cover, like its larger cousins,
sports a drawstring so that it could be fitted to virtually any optical finder
up to 9x50, with either straight or right angle eyepieces. (Yes, I could make my own cover, but
I'm no tailor either!) Many optical finders do not come with end caps, so this
cover can be useful for keeping out dust and dew. Actually, to fight dew in an
optical finder, there is another simple, very low cost option: tissue paper
stuffed down the front! I can think of two situations, however, where the TG
optical finder cover might be considered a useful option. Astro-photographers
might prefer keeping their finder scope completely covered while capturing
those award-winning photos during an all-night session. Solar observing can be
safe and fun. But if the proper precautions are not taken it can also be
dangerous. For solar observing, I take all precautions and cut no corners. So I
have two options with my optical finder: remove it to prevent the possibility
of damage or personal injury (with magnified sunlight shining through the
finder and out the eyepiece), or cover it with the TG cover. Many will prefer
the first option. I ended up preferring the TG cover. By covering instead of
removing the finder, I don't have to re-align the scope the next night out. The
aluminized surface of the TG cover keeps the finder cool and safe, and I don't
have to worry about an end cap heating up in the hot sun, popping off, and
creating a hazard. Below is a photo of my 102mm doublet set up for solar
observing. My RDF finder is mounted on the side, just below the 9x50 finder.
So here's the recap:
On the Plus Side:
Functional- performs the job basically as intended
Lightweight and durable
Low cost
Useful (IMO)
for solar observers
On the Minus Side:
Cheaper to make your own covers (or remove finders)
The RDF cover won't keep dew off forever. Those with severe
dew problems may still need to use heat tape or hair dryer
For you optical finder, caps or tissue paper may be just as effective
Okay, so is it worth it? Well, astronomy is a hobby, and
like all other hobbies, we buy not what we need, but what we want. The
TeleGizmos covers do perform a useful function. For about half the price of a
cheap plossl eyepiece you can purchase one or both covers and actually find a
use for them, rather than toss them in your "drawer of broken dreams" along
with all of those unused eyepieces and filters.
David Elosser
Post script: You may want to check your RDF finder right
now to make sure you turned it off, so you won't run down your thirty-first
battery!
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