Posts Made By: Todd Leen

Folks,

Orion at 55mm on Provia 400. Two
slides stacked, one straight, one
through a fog filter, combined 2 to 1.
Both exposures are 20 minutes at
f/3.3, Sept 27, 03.

Enjoy
Todd

Folks,

I re-processed an image from this past July ('03).
Sky-90 @ f/4.5, 40min exposure on Elite Chrome
200, AP-400 guided by STV. This is a colorful
area with many subtle hues and shades, and is
very subject to interpretive adjustment. Comments
welcome.

Cheers
Todd

Folks,

This is a re-process of an image built
from exposures made in 2002. Pentax 55mm
lens on AP-400 GTO, Elite Chrome 200.
The mosaic was constructed from 2 overlapping
35mm frames (plus several additional exposures of
the NGC7000 and IC1396 regions) that were aligned
and combined with Registar.

Cheers
Todd

Folks,

Has anyone tried Lumicon's hypered
Tech Pan (35mm) since the company changed
hands? Is this still a good product?

Thanks
Todd

Folks,

Based on advice from a friend who uses one for
4"x5" slides, and on positive response from
APML list members, I bought an Epson 3200
scanner for use with 645 astro slides.
Here's its "first light" image. I'll
run some more slides through it and
report more, but so far, it looks VERY
GOOD - and only $300 (w/ rebate)!

Cheers
Todd

Folks,

Has anyone used Lumicon's hypered
Tech Pan since the company changed
hands? Is this still a good product?

Thanks
Todd

Folks,

I finally got some clear weather in June and tried out a lens I bought
on E-Bay last winter -- a Mamiya 645 300mm f/2.8 APO. I just scanned
the slides last weekend. Unfortunately I've got a flexure problem
with the setup, so this is the only image I've posted at present. (A
very nice composition centered on M24 was ruined by trailing.) Even
on this mosaic in northern Cygnus, the stars are trailed a bit, but it
doesn't show up at the scale I've posted.

I think this lens has great potential. I've also used it wide open
with very similar results to these at f/4.0. There is some lateral
color at the edges, but I'm unsure if this is from the lens or the
scanner (Nikon 8000). I'll have to put the transparencies under a
microscope to tell. Vignetting is not a problem at f/4; I haven't
checked at f/2.8.

The image is at:

http://www.cse.ogi.edu/~tleen/astro/NorthernCygnusMosaic.html

As always, suggestions are most appreciated.

Cheers
Todd Leen

Folks,

I've been shooting 35mm with a Takahashi Sky-90 for awhile.
I've been wanting to make larger prints and so recently
picked up an AP Traveler and Pentax 67 body. First results
are at

http://www.cse.ogi.edu/~tleen/astro/GammaCygni67.html .

Compare with the 35mm shot at

http://www.cse.ogi.edu/~tleen/astro/GammaCygni.html .

The change from f/4.5 to f/6, and the larger format poses a
bit of a challenge. Though not visible at the scale posted,
there is some field rotation in this shot; and I need to go
deeper than this 1hr exposure. Unless I get better alignment,
I'm not going to be able to go to the longer exposures required.
Does E-200 push ok -- I'd like to make 16x20 prints.

Focus is also a bit ambiguous. I use a knife edge on 35mm,
but a cheap 50x Edumund pocket microscope on the 67 ground
glass screen.

My mount is an AP-400 on their aluminum tripod. According to
Astro-Physics, it should be sufficient to hold the Traveler,
reducer, and Pentax 67.

My usual alignment procedure is to use the polar scope and
then drift align at 200-300x through the scope; making adjustments
until there is no declination drift over a five menute period. This
can take me a LONG time -- up to two hours on a bad night. Then I
interchange the diagonal for the flattener with camera, and
rebalance the mount. I believe this step -- taking off the diagonal
and adding the substantial weight of the medium format flattener
and the 67 camera -- is throwing off my alignment.

Any thoughts or suggestions?

I guide with an STV and E-finder (100mm FL). I've tried to polar
align using the STV/E-finder, but a high-power eyepiece picks up
the drift quicker than the E-finder. I'd rather not go to a longer
lens (added weight and expense) for the STV just to facilitate
polar alignment.

Should I force myself to do the drift alignment with the STV to
avoid adding extra weight after I do the alignment? Should I
just add some dead weight to the mount while I'm drift aligning?
Do I need a pier instead of the tripod? Should I be looking into
a beefier mount?

(Incidently, the STV with 100mm FL E-Finder gives me
guiding errors at or below an arc second. So the
guiding is working very well.)

Thanks for suggestions.
Todd

Lucky shot -- see

http://www.cse.ogi.edu/~tleen/astro/CygnusIridium.html

I was trying hypered tech pan 35mm for the first time while
doing "serious" imaging with another optic on the same
mount. Puiblished exposure guidelines for hypered tech
pan suggested opening the Pentax 50mm lens to f/2.8 --
wider than I know produces good star images in the corners.
The result is a fabulous composition with disappointing
quality. I've learned my lesson !

Cheers
Todd

Folks,

Is anyone using one of the Trifid cameras from
Yankee Robotics? They look like a cost-competitive
entry into the high-end CCD market, but I've not heard
anything about them from users.

Todd