Saturday, December 13, 2014

Imaging from another room, Sun 20141213

I'm freeing up my playing room for my kid, so I tried to take image from my own room.  It's not as good since there is a bed so I've to place my notebook and take image while seated.  So, this is more like a feasibility test.

Since I couldn't use my desktop, and my notebook has very limited resolution and processing power, so I go back on using my Lumenera, the ASI was sold.

1129 (GMT+8), prime focus two frames stitched:-

1131 (GMT+8), with 2x barlows:-

1132 (GMT+8), with 2x barlows:-

Very nice result, the environment is not very important afterall.

The sun was rather low in the sky even in the afternoon!  It's winter time!

Tuesday, December 09, 2014

Equipment Migration

The electronic dry cabinet arrived, sad to say, even after removing the legs, the window was still blocked, but it's not a big issue.

All of my telescopes, eyepieces, filters, optical stuff, camera lens and cameras could be packed inside, and there are still some space left. 

What are left?  The mounts, and various adapters, etc.  They don't have to be stored in humidity controlled environment, so maybe I can just buy a box to place them along with the dry cabinet.  This dry cabinet occupies half of my windows platform.

Monday, December 01, 2014

Adapter plate for my Nexstar SE and Gitzo tripod

The Nexstar SE does not have standard camera tripod interface, but three 3/8" threaded holes near the edge.

Therefore, I have to create a metal plate having one 3/8" threaded hole to connect to the tripod, and three 3/8" holes to connect with the base of the Nexstar mount.

Finding such a plate is pretty easy and at the same time, hard.  We don't have to use a strong plate since it's just "the meat between the sandwich", and I believe even a plastic plate will do the job nicely.  We will need a plate of around 9" diameter.

I placed a piece of paper over the base of the Nexstar plate, and use pencil to mark the holes.  Then I stick that paper over the metal plate for drilling:

I drilled one more small hole beside the 3/8" screw, i.e. the guiding pin of the Gitzo:

Placing the plate between the original mounting plate and the tripod:

Fixed the Nexstar mount on top via those 3/8" holes:

Frankly, there are some vibrations but it's acceptable since this setup is only for visual purpose, photography is another story but then it's not a photographic mount afterall.

Further thoughts:

A bigger plate could be made so that the excess areas could be used as eyepiece holders by drilling 1.25" and 2" holes. 

Thursday, November 27, 2014

Electronic Dry Cabinet

Size of my windows platform: 44" (110cm) x 22" (50cm) x 16" (44cm)

Maybe I could try to find an electronic dry cabinet instead of tailor made a regular wooden cabinet, the price should be quite similar?

Some of the size of my gears:

Tele Vue Ranger: minimum length = 42cm

Celestron C5: minimum length = 35cm, thickness = 16cm

Solarmax 60 box: minimum length = 33cm, thickness 21cm, however, the box could be stored else where

Actually, most of my other stuff could be stored in a regular cabinet.


Update on 2014/12/01:-

I will buy one shortly since the price is right, just similar to a regular wooden cabinet, but then I will have a wooden cabinet too by its side.

Inside the dry cabinet, I should have:

1. Camera and lens: 450D, kit, 50mm f1.8, 8mm fisheye, 200mm f2.8L, Kenko 2x

2. Eyepiece and barlows: 20mm widescan, 4mm TMB, 2x barlows and 5x powermate

3. Telescopes: C5 and Ranger

4. Filters: Solarmax II 60/BF10, Baader, etc

Should have enough room...


Update on 2014/12/04:-

Ordered one and shall be for delivery ready next week.

The dimension of the dry cabinet: W537*D358*H456 

Shall be able to fit in my Ranger which is the longest stuff, and my C5 which is the thickest stuff among my gears.

The legs could be removed, and hopefully just fit my window platform without hindering the operations.

Battery life of 18650x3 on Nexstar SE mount

I counted and there are more than 10 observation sessions, each over half an hour and the battery is still going strong. 

Having said that, I will recharge them today since Lithium battery should keep more charge to be healthy.

I'll need 3 of them at a time to give 11.1V, and I've six of them.  So, this should be more than enough.

Monday, November 24, 2014

20141124 Sun

Sky condition very poor today, so I couldn't do anything else except a 2 frames mosaic as below as a record, no flat field:-

Taken at 1507 (GMT+8).

Sunday, November 23, 2014

20141122 Sun and experiment with flat field

The CMOS sensor of ASI 120mm is quite sensitive in creating Newton's ring.  I found it's pretty terrible in the last imaging session.  People suggested that Newton's ring could be removed by tilting but then it involves on more adapter and it's not really a good way indeed.

An alternative approach is to do a flat field which can remove the Newton's ring as well as any dust on the CCD.  A flat field could be acquired by de-focusing the image a large bit, and I found it natural for the whole work flow.  I normally do a prime focus shot, and then pump up the magnification by adding a barlows/powermate, and before I refocus with the barlows/powermate, I simply capture a flat field first!

First up is a mosaic of two shots, taken at 1151 and 1153 (GMT+8) respectively.

So, two shots were taken afterward by using the method above with a flat field.  The first one is done very close to the flat field, so the Newton's rings were removed completely.  It's taken at 1157 (GMT+8):-

Next one is taken at 1159 (GMT+8), I don't exactly know, but seems like the Newton's ring is not as cleanly removed as above.

There might be two reasons:

1. field rotation since I'm doing alt-az tracking with the Nexstar SE mount, I found it unlikely, however

2. the flat field was not done correctly, since the solar disc was not occupying the whole frame, so the flat field is only partial, some dark corner was not illuminated afterall

So, next time when I do a flat field, I shall move the camera to the center of the solar disc.

Friday, November 21, 2014

Home@Walnut Changes (again)

Formerly, this room was my playing room.  There is only a computer, and a store room of my equipments.  But then when my daughters have to learn piano, I need to spare some rooms and so I sold my C8 and downsized to a C5.

Recently, my daughters requested their own room, so I have to move out from this playing room altogether.  My faithful self-design computer desk with storage cabinet has to be thrown away.  Actually, the upper half had been discarded when the piano moved in but now the whole thing would be gone soon.

I'll need to find a replacement.  Last night, I've measured the window platform of my own room and I found that it was 42" (width) x 22" (depth)  and then I could make a cabinet as high as 16" without blocking the windows.  This cabinet will be tailor made to store all my existing stuff inside, and I will be taking photographs from inside by using my Nexstar SE mount there and there should be enough room.  However, I couldn't use my desktop PC to take images by then and I've to go back to my Eee PC which should suffer from much lower frame rate?  Maybe it's time to upgrade with a better computer?

Before it was killed, let's take a photographs in remembrance:

Top most level for my Camera gear which consists of a Canon 450D, a kit lens, a 50mm f1.8, a 8mm fisheye and a Canon 200mm f2.8L plus a Kenko 2x, a couple of manual macro tubes, shutter release, flash, etc.  And there are two new members namely the ASI 130mm and ASI 130mc.

On the second level is my trusted Ranger, my Mark-X, eyepieces and accessories box.

On the third slim level is my Canon 10x30 IS, and some miscellaneous stuff.

Finally, the lowest level is my C5, plus my Solar 60.