Wednesday, June 1, 2011

OK back. New Gear.

Sorry, been busy.

Work, illness, weather, etc etc.  Life stuff.  But it's not like I've been idle.  No sir.  In a fit of pique I turned my back on my beloved T2i DSLR and purchased a bright shiny new QSI 583.  I finally got frustrated with 1.) lack of red sensitivity (I never modded the camera) and 2.) headaches of "one-shot color".  The latter which includes a variety of sub issues like dealing with bayer/de-bayering, color balance, and taking good quality flats with very small focal length (<100mm) lenses.  A full explanation would  take a multi-part post which I may yet write up ... someday.  Let's just say I fought the good fight, learned a great deal in 7 months, and decided to change one hair-shirt for another.

The DSLR will retain it's place for "regular" photography and astro-landscapes.  But for deep sky work count me a convert to the new challenges of CCD.  There are some great KAF8300 CCD chip cameras out there but I selected the QSI for a couple reasons.  The integrated filter wheel is the bees knees.  I wanted something compact for continuing work on the Astrotrac.  And I loved the idea of the off-axis guider with the pickoff mirror *before* the filter wheel for those times when I image with the refractor.  The camera is fully compatible with all my EOS lenses so I was good to go out of the box (purchased with the EOS adapter of course).  Note that the off-axis guider does not work with camera lenses ... back focus issues ... but the camera design is flexible enough to remove the OAG with just a few screws and replace with a thinner coverplate.  Nifty.

I'm not taking responsibility for all the planet's "end-times" weather and natural disasters but the new gear / bad weather correlation sure seems to hold.  If it was me, my apologies to humanity.  What is certain is that there have been precious few clear moonless nights to play with my new toy.  The down time was useful to do some serious gear-fu and I'll post a few pics of the progress below.

New QSI 583 with Canon 200mm EF-L f/2.8
I really wanted to address the challenge of frame rotation.  One attaches the camera by the 1/4-20 holes in the body (which requires some kind of ungainly ball head for rotation) or by telescope rings holding the camera lens.  The latter allows for free rotation but requires one to loosen the tube rings, rotate, tighten tube rings, check framing, then say bad words.  I wanted to avoid the saying bad words part.

My solution was to purchase a Canon tripod lens mount - the white thingy in the picture above.  I was concerned about how firmly it would hold everything but I can report it is rock solid.  Just loosen the white knob, rotate in place, re-tighten.  The center of the frame remains, uh, centered.  It really works.  Just be sure you don't cheap out and buy an aftermarket lens mount.  Close your eyes, spend the $ and get the official Canon one.  My bet is you will end up buying one anyway after your e-bay knockoff fails to please.

Micro focus gizmo
I've written before about the trials and tribulations of achieving good focus.  And if once achieved keeping it.  At short f ratio, if a mosquito lands on the focus ring one is doomed.  Above is my version of the venerable micrometer/spring/hoseclamp solution.  The unique holder is a piece of curtain rod mounting plate that was floating around the garage.  I can report that it too works great.  My only complaint is that the ease of rotation mentioned above is offset by the hassle of loosening the hoseclamp and spring, rotating, and reattaching back into place.  It is a small price to pay for the joy of fine focus control and then holding it for the duration.

Mounted on the Astrotrac
Here we are mounted on the Astrotrac.  The dovetail rig is replicated on my AP900 mount so it is a simple task to move between mounts.  I also attached a red-dot finder to the side of the QSI to help with locating objects when on the Astrotrac.

All ready for some clear skies.  Waiting ... waiting ... waiting ...
Truth in advertising ... I have yet to field test the above.  I have taken some images on the AP900 and I'll show you that arrangement in a post to come.  Enough gear jiggering for now ... time for the weather to clear!

1 comment:

  1. Very nice blog. Keep up the great work! /px