Friday, January 11, 2019

20190111 Sun

This is the first imaging session for 2019!

First up is a full disc shot at 0721 (UT), foggy sky but rather nice seeing.  The solar surface remains inactive, note the bigger prominence on the 9 O'Clock position.

Close up at 0726 (UT), higher gain faster shutter, higher fps as a result:

Another close up at 0729 (UT), lower gain slower shutter, lower fps as a result, but less noise:

For better seeing, we don't need high fps or faster shutter to freeze seeing... slower shutter and lower gain means less noise!

Friday, January 04, 2019

Canon 24mm f2.8 STM and Canon 10-22mm f3.5-4.5 USM

Since I've started some simple astrophotography during my camping trips, I gathered enough reason to re-organized my lens line-up finally.

What was missing from my collection is a really wide angle lens.  I have been using a 8mm f3.5 manual fisheye lens for that purpose before, but then it has limited usage during day time, and it is a little bit too wide if I have only one lens.  You took a few shots and those will cover the whole sky!

Therefore, a 10-22mm or a 10-18mm is always in the wanted list.  Today, I get a great 2nd hand deal on a Canon 10-22mm, the lens is aged but it works.

And for ultimate portability, I got another nice deal of a brand new pancake Canon 24mm f2.8 lens a couple of days ago, too!

Vignetting is rather heavy if it was used wide open, but for the price, its size and weight, it is a must have other than my existing 50mm f1.8 lens.

Let's see how they work out.

Wednesday, December 26, 2018

20181226 Sun

0827 (UT), the solar surface remains boring, except a small active region on the upper right, and a few small prominences.

Ranger with Solarmax II 60 with BF10, with the reducer on.

Friday, December 21, 2018

Chuwi Lapbook 14.1

I've a cheap Chuwi Lapbook 14.1 laying around and it could be used for astronomy purpose.  The first thing I will need to do, is to expand its storage, so that it could store more images or even video from Sharpcap.  This is only possible with the earliest version of the model which comes with a m.2 slot, later versions have it removed silently.  On simple disassembly, I found that I am lucky enough to have the original version!

I got a really cheap one from taobao, and it has 128G in size, which is about right in terms of price and size!  It makes no sense to buy something expensive for a cheap notebook!  128G will triple the original size!  This SSD has a form factor of 2242, but it also comes with two detachable parts for better compatibility with bigger form factors.

Windows managed to detect the SSD without problem, and after simple partitioning and formatting, it's ready for use.

A quick speed test was conducted in Sharpcap, it's way faster than the original internal SanDisk eMMC!

In addition to my Voyo, this Chuwi could be used as well.  I suspect it will yield higher fps than the Voyo which features a faster CPU.

Saturday, December 15, 2018

20181213 水浪窩 雙子座流星雨?



Canon 450D modified, 20s exposure at ISO 800, fixed tripod.

Minimalist style camping, less than 9.2kg total.

Tuesday, December 04, 2018

20181129-1130 Modified Canon 450D first light (Camping in Chek King)

I went for a camping trip and astrophotography was only a very small part, so I used a mini-tripod with a small ball head only, and I only had my Canon 50mm f1.8 with the modified 450D.

To keep the story short, I found that the 50mm f1.8 could no longer reach infinity focus when the IR filter is removed!  The 50mm f1.8 has very limited focus travel, and this is the problem.  Notice that it's not autofocus that fails, this is anticipated due to the change of the optical path length.

It's one of the best night for the last decade, luckily I've my Canon 10x30 IS with me and I enjoyed tremendously!

Sirius with M41, I love to catch the view when it's still low in the sky, the tree as foreground is very nice!

M31 at the corner.

M45 hanging just above the trees.

The Orion and M42 just went above the tree!  Note that red color on M42, it used to be purple before.

Later I found that if I insert a CLS filter between the lens and the camera, it will reach infinity focus again!  Next time I shall try this one combination out.

For wide field, maybe my Canon 70D is better due to the movable LCD, composition should be far easier.  The modified 450D might be better for targets richer in H-alpha.

Sunday, November 11, 2018

20181111 Sun

The sun surface is still quiet, 0653 (UT), taken with reducer on:

But on carefully second look, you could see two small prominence at the 1 O'Clock and 7 O'Clock direction.

So here are two shots with 5x Powermate, and reducer removed.

First at 0701 (UT):-

And then second at 0706 (UT):-

The Solarmax is not very good at imaging these.