Transit Practice

With excitement for the coming Venus transit this coming Tuesday (June 5) I ordered me up a Canon Extender EF 2X III to double the focal length of the 200mm lens.  As I learned from the annular eclipse the image scale (for the sun) with the 200mm is pretty meager.

I took the following picture yesterday and while the sun still doesn't fill much of the frame it is more than  adequate for my transit purposes.  All I really want is a record of having lived through it and if all goes well assemble an image sequence into a movie.

Here is the full frame with the T2i.

Ol' Sol

I took that image, brought it into Pixinsight for enhancement and colorization.  Here is the result after a heavy crop.

Detail visible after processing in Pixinsight.  Please click for larger size - it's much nicer.

Focusing is a challenge ... in full daylight it is difficult to see the camera screen.  Autofocus does work but I'm not absolutely certain if I could improve on that with manual focus or not.  The above was focused manually using the buttons on the control box for the robofocus.  While it was the best of the lot it a moment of good seeing could easily account for the improvement.


Taken in my backyard in San Jose, CA  May 31, 2012
Canon T2i (stock), Canon EF 200mm f/2.8L + Extender EF 2X III @ f8
Baader solar film over lens cap
AP900 mount
1/640 sec exposure @ ISO100
post-processed in PixInsight

The Hairshirt Goes Social

The Eclipse of 2012 was probably the deepest I'll see in my lifetime - without travel that is.  Part of me was wishing I'd made the 3-4 hour drive to see the full eclipse but it was still pretty impressive from my backyard in the San Jose area.  We had some some friends and neighbors over for a BBQ and in the end it was a wonderful way to enjoy the eclipse.

I set up with my 80mm AT-LE refractor and 12mm Nagler with a Baader filter on the front. An hour before the event I realized that with so many guests it would be best to rig up a projection.  I quickly taped a piece of white paper to the bottom of a cardboard box and then fastened the box to the ball head on my tripod.   Off came the Baader filter, and after some focusing and moving the box to and fro a very nice image presented itself.  The full solar disk about 8" in diameter.  Multiple sunspot complexes were easily visible with the lighter grey penumbra easily visible on the largest of them.  So many sunspots made the eclipse just that much more interesting.

Eclipse equipment with "spokes model"

I had the Canon T2i clicking away a picture every minute through the 200mm lens.  This was a very good dry run for the Venus transit since I learned that I'll definitely need to borrow a friends (you know who you are pal) 100-400mm.  The disk image is just too small at 200mm.

Even so, I'll attempt to assemble a time lapse of the eclipse event - if for no other reason than to practice up for the Transit on June 5.

As written in a post below, the practice of imaging is largely a solitary pursuit.  With other imagers nearby it can be a shared experience but in the end it is just you, the camera, the mount, the computer, and a horrible tangle of wires and cables.

Sharing the eclipse, live, with nearly 20 onlookers was great fun.  The youngest was 18 months, the most senior over 90.  It was satisfying to share something so unique with a group of friends.  Yes, the hairshirt monk does go social every once in a while.

But there was another aspect.  A more intiment moment of sharing.  One that I wouldn't trade for pinpont stars across the field.  Or for the lastest gear.  Or a set of perfect Flats, darkest skies, deepest image.  It is the moment of connection with another over this instance of wonder.

Today's connection: mid-eclipse

 It's when another looks at an image, or through a telescope, or even with naked eyes at a dark sky and gets it.  It's when another sees what I see and there is the ah-ha moment.  Doesn't happen frequently but when it does it makes all the hard work of imaging worthwhile.  I was thrilled that it happened today.

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!

Jiffy Pop time

It's that time of year.  The 11th Annual CalStar starparty will take place at Lake San Antonio, Oct 7,8,9.  I'm heading down early.  I don't make it to any other large multi-day starparties - for me, this is it, and my favorite.

I've done visual astronomy on and off for, well, a long time.  This will be the first year I am taking the camera.  But instead of ditching the eyepiece I've found that taking images has actually rekindled some of the old passion for observing.  I've stared at some objects for hours and hours as I processed the images - now I want to appreciate them over again using a different media.  This one more subtle, more ephemeral, more personal.

To that end, I'm actually pulling out my Obsession 18 which has been gathering dust in the garage for 3 years.(truss poles - check,  ratchet do-hickeys - check, actually packed the wheelie bars and ramps - check).  My fantasy will be to get the camera ripping pictures for an hour unattended while I calmly push the giant dob around.  More likely I'll be fussing over the camera gear, tripping over wires, then spending way too much time trying to find that first star to just start star hopping.

I'm also bringing along my AP900 mount.  The mount I bought some 10 years ago to do astrophotography - but still haven't taken a single picture with it.  How's that for making a silly purchase before I was ready planning for the future?  (counterweights - check, mounting plate bolts - check, hand paddle- check, blue tops -check).

Then there will be my trusty AstroTrac ... bing, bang it is all set up and ready to go.  Takes all the fun out of the hours of set up and fussing required for a "real" mount. (manfrotto head - check, um, huh, not much else to forget).

Three mounts, two scopes, one camera, 3 lenses.  Way too much.  And this year I'm moving a little slower.  But the way I'm thinking of it ... I'll have a lot of choices, 4 nights, and the best company one could ask for.

The *only* reason I still own a pickup truck.

The careful observer will notice that picture is a rather wide field.  Yes, first light for my newest toy.  More on that later!

Yes, time again for Calstar.  Can't wait for that 1am break time. A chance to warm the insides and enjoy the simple pleasure of Jiffy Pop shared with friends.

Drive that Spike

Remember that post about making the bobby pin Bahtinov mask ... the "Happy Face"?  I ended up using it only once.  Well, there was only one night worth using it but that is beside the matter.  On *that* night I wanted everything to be as good as I could make it so I figured since I spent so much time making the blasted thing I might as well use it.

Focusing is a hard.  Like real hard.  Especially with a short focal length camera lens at wide open f-ratio. The slightest touch of the focus ring (no - autofocus doesn't work - too dark even on a bright star) is enough to make your stars look like they have had nothing but Micky Dees super-sized combo meals for a month.  That and surrounded by halos of all colors.  Bah!

For this trip I mostly just used live view on the Canon back mag'd up to 10x and tried to make the stars as tiny as possible.  Worked well enough for the conditions.

Here I took a picture at ISO3200 for 5 sec then reviewed on the camera back (blown up 10x) and by the tiniest touches tried to get that middle spike in between the X.  Back and forth.  Nudge, shoot, review, nudge, shoot, review (say naughty word), nudge, shoot, review (say naughty word), nudge ... you get the picture.  I kept the last picture, said "good enough", resisted the temptation to touch focus again without the mask and carried on with imaging.

Handy tip ... remove Bahtinov mask before imaging run.  Yeah.  Wouldn't that be something.

Fortunately I had to frame my shot with test exposures and noticed the stars were all dim and funny looking.  Yikes.

Center the Spike!  Bahtinov focus on 200mm Canon EF-L at f/2.8

I only just now thought to take a look at that image under the light of day.  Much easier to see on the computer screen than while on your knees craning your neck to see the camera back.  Looks pretty good - just a touch off - but it would have taken luck to place that spike any better.  The only way would be to use a fine motion focus ring attachment - something I have been working on.  More on that another day.

I'm happy with the focus on the Andromeda shot - don't really think I could have gotten it any closer.  The Bahtinov mask is cool and a real savior for those imaging with telescopes.  I'm not sure it is of much help with 200mm or smaller camera lenses, but it was fun to make while the storms rolled by.

Stacking no Tracking

It might seem strange but honestly I never considered that there would a condition somewhere in between Raining Like Cats and Dogs and Darkest Skies You Have Ever Seen.  Not only is there such a condition it is by far the most likely one I am going to experience if there is any break in the seeming perpetual cloud-out.

Actually it happened last night.  It was raining at 9pm.  By chance happened to look up at 9:40pm and ... "that's a funny cloud".  Yeah.  It's commonly known as the Milky Way.  Now mind it is still partly cloudy but I was still elated to see a "poke your eye" out MW.   It takes me 20minutes to get back to our hovel and decide that it is not worth it to pull out the Astrotrac and go full-auto.  Instead I just grab the tripod, a 50mm f/1.4 lens and figure I take some short duration shots under various conditions so I can say that I at least took some kind of image of the stars.  Basically I was going out with not one piece of equipment that I so painstakingly shipped out to New Mexico.  No mind ... I'm on it.

About 45min later the sky was extinguished and the rest of the night was full of lightning and heavy rain. None-the-less I got a couple images and learned some lessons.  Lessons first - images later.

1.) The 50mm f/1.4 lens is cool (so much freaking light) but it is no red-stripe.
2.)  It is near impossible to focus at f/1.4 while looking at a live view screen.
3.)  Plop down some $$ for a nice carbon fiber tripod.  Cheapie tripods, well, lets just say some language that I wouldn't use around the girls was spoken into the night air.
4.) In a serious pinch ISO3200 will do.  A serious pinch.  Noisy but OK if you downscale.
5.) Don't panic and shoot wide open.  The lens can buy you a lot even stopped down a notch or two.
6.) Acceptable trailing is in the eye of the beholder.  My eye didn't like anything more than 10sec with a 50mm lens.
 7.) Trying to frame a shot near the zenith while mounted on a tripod is desperation in action.

Never shy to try something completely new and abandoning my detailed planning (read making stuff up on the spot) I thought I might shoot a bunch of short duration frames, shoot some darks, and try to stack 'em.  While my images look like crayola (bad focus, jumpy tripod, lens not set correctly) I think this idea has merit (I'm sure others have tried this).

So ideally one would:
1) shoot as high an iso as acceptable
2) lens as wide open as acceptable (but probably stopped down a bit)
3) turn off in camera dark frame
4) shoot a bunch of darks to bang down the noise
5) shoot flats (I didn't and wished I had)
6) stack lights with translation and rotation settings and let software take care of image shift
7) process to your hearts content

With some practice and experimentation I think some very nice wide field images could be had with no tracking mount at all.  The below is a stack of 25 10sec exposures at f/1.4 and ISO3200.  Same number of darks.  All on a static tripod - no tracking!

Cygnus near Deneb with a tiny teeny North American nebula below.  Wish I had come at least somewhere near focus and shot some flats.

It's a Smiley Face

I've had lot of lazy relaxing time during the days.  Some of that time I've used reading Ireland's Photoshop Astronomy but after a while it was just got too cerebral.  My brain needed something more hands on and tangible.  I decided to make a Bahtinov focus mask for the 200mm and 100mm Canon lenses.

I thought I might do this before leaving on this trip so I brought a printout of template and a few supplies.  I scrounged up some glue and tape from the library here and went to work.  The problem with a Bahtiov mask for small diameter lenses is that the pitch of the gratings needs to be rather small to pick up more of the diffracted orders.  Cutting thin bars out with an x-acto knife was not my idea of fun.  I'm not sure what I came up with was any easier but the end result was nicer.

I noticed that the bars were just about the width of a bobby pin.  I brought along a pack and went to work bending and snipping with the leatherman tool.  Then taping and more glue to put them in place.  A couple long hair-shirt hours later ... here is the result.

My bobby pin grating Bahtinov.

 A number of people came by curious, asking what I was doing and what a Bahtinov focus mask was.  I was challenged to explain but my 6 year old daughter satisfied them all with her answer.

"It's a smiley face".

Gear has Landed

The Box arrived during lunchtime today.  I asked a ranch hand to help me load it into the rental and I drove it up the Mesa for inspection and unpacking.  I freely admit to fussing a bit on the packing and thought I had probably overdone it.  Glad I did as the box was a bit more worse for wear than I expected. All the contents were safe but I won't know for sure until I actually go to set it up and see it running.

I had planned to reuse the box for the return shipment but now I am not so sure.  I might just try and find a replacement when I drive into Santa Fe this coming Sunday.  For now this part of the saga is over.  Now to work on the weather ...

1ZE719850347545190

I fussed for quite a while on how to get all this stuff to New Mexico.  We would have enough weight allowance on Southwest to get it there via checked baggage.  But that would mean two extra big bags to lug around the airport.  As it is we already have 2 large checked roller bags and each of the 4 of us have a sizable carry on.  Mine is camera gear.  Kimi has all the useful stuff.  The girls have their school bags filled with toys, books, coloring stuff and snacks.

In the end I bought a mini-wardrobe box at the hardware store.  24'x24'x42" Three main bags (and some last minute stuff-ins).  Then a whole lot of pillow bags and bubble wrap.  Strapped in tight.  Nice and secure.   Here is our final farewell.

UPS ground - air was too expensive after insuring.  Should arrive the day after we do.  Fingers crossed.  I keep tracking the number in the title of this post ... it's halfway there ...

The Gear

You know,  I really should be packing.  Useful stuff - like underwear and water bottles.  Making sure we have what we need for 2 weeks of family vacation.  In attendance for the first week will be my wife and two daughters (ages 8 and 6).  A week later our friend Marc (ShuShu "uncle" to the girls) will join us with reinforcements (that is, all the stuff we forgot).  Yes, I really should be packing.

But instead I'm writing a few lines about what I "pulled together" over the previous 8 weeks or so.  There must be some rule about astronomy gear.  Something like "whatever your budget or think it will cost - triple it and you might have enough to get by if you have enough 1/4 screws, duct tape and batteries".

All my current gear is big.  Heavy.  As in, not shipping to New Mexico.  Must find light gear - oh, and suitable for astrophotography.  Yeah - let's add a completely new discipline to the mix just to make it more fun!  This is gonna be so cool.

The Gear.  Hey Marek ... Polar Aligned yet?

Read on for the shopping list - and my single handed attempt to keep the world economy from collapse!