EbolaBooze’s Astro Corner: Telescopes! Huh, yeah, what are they good for?

Absolutely no-

Let’s stop there.

Since I bought some telescope parts a few weeks back, it’s been nothing but storms, hail, cloud and rain. Well, at least I’ve kept my 100% hit rate for telescope purchases to inclement weather!

So instead, let’s have a pictorial guide on the different types of telescopes, and what they’re good for – strengths and weaknesses!

Let’s start with a classic – the refractor!

 

Refractor Telescopes

A refractor telescope at its most basic consists of two lenses – an objective (the light-gathering element) and an eyepiece. Refractors suffer primarily from chromatic (failure to focus all colours) and spherical aberration (failure to focus all light rays at a single point). Modern refractors can use up to six glass elements of varying optical dispersion and design to correct for these aberrations.

For astronomy purposes, two refractor designs are prominent: achromatic refractors and apochromatic refractors, with accompanying sub-designs.

Achromatic refractors are the cheaper of the two types, correcting for some spherical aberration and bringing only two wavelengths of light to a sharp focus. These are good beginner visual astronomy telescopes, as apertures of up to 152mm (6”) can be cheaply bought (~$700), and due to the lack of additional glass elements are lighter than apochromats.

starwave_152mm_ota5_m

Apochromatic refractors have two or more glass elements, with an extra-low dispersion (ED) element to bring three wavelengths of light to a sharp focus, and remove virtually all spherical aberration. Obviously, using more elements and more expensive glass raises the cost and weight of these telescopes significantly. 80mm aperture apochromats are $600-$800, with price increasing significantly once apertures are larger than 120mm.

esprit120

As a rule of thumb, most affordable refractor telescopes tend to be of short focal length (<800mm), and small aperture (<152mm). Refractors tend to be the most versatile telescope design, useable for visual, as well as planetary, wide-field and deep-space imaging. For a given aperture, their views are more contrasty and brighter than pretty much any reflecting or Cassegrain telescope type, due to the lack of central obstruction. The larger apertures are prohibitively expensive though!

For planetary views, good colour correction and a long focal length is needed – 1200mm is about the lowest you want to go. You can get this focal length by adding a Barlow lens or a tele-extender to your visual train. This will allow you to see the bands of Jupiter and the rings of Saturn with ease on a good night. For deep-space views, aperture is king – a 152mm achromat will serve well.

 

The list of refractors that are good for imaging are as long as my arm, but what is important is that the majority of mid-price apochromatic refractors project what is called a curved focal plane. This has no bearing on visual astronomy, but is important to note if you want to use one for imaging. The effects of a curved focal plane means that the stars in the centre of your image will be in sharp focus, with the stars further out being blurry and distorted – the amount dependent on the degree of curvature. Below are two examples, at the high and low-end of imaging refractors to demonstrate what some extra glass can do.

My imaging refractor is a SkyWatcher ED80, a two-element ED semi-apochromat at f7.5, with a focal length of 600mm, so a pretty slow scope. It needs a field flattener to produce decent images.

The Takahashi FSQ-106ED (on my Lotto wishlist, at a cool $5300), is a four-element apochromatic Petzval design refractor, and it’s corrected for astigmatism, coma, chromatic aberration, spherical aberration and field curvature. No correctors are needed, as the correction is part of the optical design.0038147_takahashi-toa-150nfb-double-ed-triplet-ortho-apochromat-refractor

Hopefully that was informative; I’ll be talking about Newtonian telescopes next time!

 

Clear skies!

lorekai: Built a Lego AT-AT instead of playing games.

So nothing to review this week, but it’s a pretty cool AT-AT, so time well spent. Though I am close to being able to review both Tales of Hearts R and Alpha Sapphire, as I’m approaching endgame in both, though with the release of Persona Q looming large it’s likely that I may end up distracted once again. Too many games released at this time of year, my wallet is crying.

marsy: Dragon Age Inquisition

So the new Dragon Age game came out about a week ago. It’s looking like it’s going to be a really long game, mostly because I’ve played for about 15 hours and achieved fuck all. That might just be me though. Important advice for new players – LEAVE THE HINTERLANDS! It’s not very clear at the start that you need to leave the area to progress in the story. There are heaps of little side quests you can do but it’s very easy to wander off somewhere that you are not levelled up enough for and have your whole party killed by a bear. Not cool.

I really like the idea of Dragon Age Keep – instead of importing  save files over from the previous games, you input your choices online and they are sent to your game that way. Makes sense considering this game is available on next generation consoles. Mine is on the Xbox 360 though because I am much to cheap to buy another new console this year. Not important. As I was saying, I like the idea of Dragon Age Keep but it doesn’t actually seem to work from what I’ve noticed. I’m quite certain that my Warden didn’t die and Anora is not ruling Ferelden. Not sure why it didn’t work for me, but it’s highly likely I just messed up somewhere.

Music in the game is nice, but it gets very broken up when loading things. Scenery is nice. Characters looks nice, but perhaps a little too shiny. Character customisation is very extensive, but the hairstyles still all suck.

I decided to play as a rogue elf. What I find fun is that my character is a Dalish elf, and the game goes on and on about how I’m supposed to be the “Herald of Andraste” (who’s kind of like Dragon Age Jesus, I guess) and it’s in character for me to be a little shit and tell everyone that I think their religion is rubbish. Fun times. I’m also going for my usual gaming style of hit on everyone possible. It’s working for me so far, although I looked it up and apparently there’s diversity in the sexuality of the romanceable characters. So I can’t actually get with everyone. Disappointing.

This is definitely a fun game so far – it has a very Skyrim feel to it, but with a bit more structure. I recommend Dragon Age Inquisition and not just because I have extreme love for the Dragon Age series.

wildfillysama: Nanowrimo Day 24 (Intermission)

Words written: 36,519

Words should have written: 40,008

Verdict: 3 days off, plus a flight = not conducive to typing.

Also, I’m knackered.

This is why I should never remark on how well things are going; it will always invite disaster and/or disarray. In fairness, this has come in the form of a few days visiting friends in the south, then flying up to Hong Kong to visit family/do immigration stuff. However, my tentative lead has slipped.

Tomorrow and beyond will be a quick and brutal round of catch-up. Hopefully.

Moral of the story: no fun allowed in Nanowrimo. Only typing. Billions of typing.

On the bright side, the novel continues to be novel-shaped, which makes a pleasant change from the usual sea of notes, mismatching dialogue and vagaries that usually make up my attempts at writing fiction. The end is in sight, and it may even be legible.

 

Watch this space… and good luck with your novels!

An Open Letter to (some) Forensics People

Dear Forensics People,

When you send out DNA to be sequenced, please, please, please, pleeeeease make sure that the test requested is appropriate, and the DNA is actually useable before you ask to have very expensive and time-consuming tests done on it.

Case in point – the glowing band with the big fat red arrow pointing at it! That band of DNA, according to the size marker on the left-hand side is approximately 200-600 base pairs long. THAT IS NOT GOOD QUALITY DNA. NOOOOOO. BAD QUALITY DNA. BAAAAAAD. I would have to actively try to fragment the DNA to get a band this small when extracting DNA, even from days-old rotting cadavers.

Shitty forensics DNA

The majority of the other glowing bands on that picture are DNA fragments that are ~10,000 base pairs long, which is a good length and ideal for most DNA sequencing applications.

Being able to exctract DNA of this quality shows that you are actually halfway competent at handling various human body parts, and have the requisite three brain cells available to use a DNA extraction kit, which is the molecular biology equivalent of a shake-and-bake mix for paraplegic retards.

 

Actually, I don’t have the foggiest idea WHY any forensics-related human DNA would be sent to us for sequencing in the first place! Human DNA sequencing tests that my lab performs are RNA transcriptome, cancer-specific panel, whole-exome, whole-genome and targeted panel sequencing! More to the point – NONE OF THOSE TESTS HAVE ANY FORENSIC USE WHATSOEVER .

 

So, certain forensics people? (you know who you are) Learn to use a DNA extraction kit properly, educate yourselves on the tests you request, and maybe READ WHAT TESTS A LAB CAN DO BEFORE YOU START WASTING OUR TIME AND MONEY.

 

Kind regards,

EbolaBooze

lorekai: Nostalgia incoming.

In less than twelve hours from now Pokemon Omega Ruby and Alpha Sapphire will be releasing here, and as the third generation games are my favourite, I’m a little bit excited, so this week I’ll be talking about my Pokemon game experiences.

 

Generation One:

Versions played: Blue and Yellow.

What I remember most about these games, aside from my super awesome Venusaur, in Blue, that killed everything, are the many stupid things my childhood self did, including going through Rock Tunnel without flash, because I didn’t know it existed and I just thought Japanese games were really hard, and using my masterball on a Raticate to see if it worked, and then releasing that Raticate in hopes that I would get it back. I also have the way through Silph Co forever burned into my memory due to the amount of time I spent wandering around lost in there.

 

Generation Two:

Versions played: Gold and Crystal.

Also remembered largely for stupid decisions, slightly fewer than the previous games at least, although I did kill a shiny Rhyhorn because I thought it was a glitch, despite already having the red Gyarodos. Also as the original copy of Crystal I played through was a less than legitimate translation of the Japanese version, I remember great deal of confusion about the giant Pokemon Centre in Goldenrod City, that to this day I am still not entirely sure of the purpose of.

 

Generation Three:

Versions played: Sapphire, Emerald, and Leaf Green.

Between Sapphire, Emerald, and the Golden Sun series, these were the first games that I ever considered from an aesthetic standpoint, that ever made me think that in game locations could be beautiful, it was probably a lot in part due to early teenage pretension, but it helped set the standard for how I look at games today. Furthermore I did a lot fewer stupid things in these games, it was the first time I actually raised a proper team, and gave vague thought to strategy, rather than over leveling my starter and just plowing through.

 

Generation Four:

Versions played: Pearl, Platinum and Heart Gold.

Aside from the gen two remakes, which I adored, generation four I feel is the most forgettable, and is overall my least favourite. It’s not bad by any means, but the only thing of note that I can really think about it is the Physical/Special split, I can’t even call any of the soundtrack to mind, whereas with all the other games I can. The Sinnoh games are also the only games where I don’t like any of the starters, which is one of my biggest problems with it. To be honest I think I went into them knowing too much, playing them the first time round I was over-hyped and they couldn’t live up to my expectations.

The gen two remakes on the other hand  are awesome, aside from being well made remakes, that were both faithful and managed fixed most of the problems of the original release, the Pokemon follow you! And it’s cute, and they give you things, and I love it!

 

Generation Five:

Versions played: Black and Black 2.

My opinions of Black and Black 2 couldn’t be more different from each other, if it weren’t for Black 2, generation five would be my least favourite by far. Black is the only game in the series that I have not been bothered to beat the Elite Four in, I liked the new pokemon, I liked the changes it made to improve the story and add characterisation, but the game itself felt both formulaic and linear, and it lacked the charm of all the previous games. Black 2 on the other hand is close to being one of my favourite pokemon games, it approached the series from a different angle, but still managed to catch the feel and overall charm of the previous generations.

 

Generation Six:

Version played: X.

I reviewed X as one of my early posts in this blog, so if you want to read my full thoughts on it you can find them here, if not then in short I very much enjoyed it, but I feel it lacks in post-game content.

 

That’s all for this week, thanks for reading, next week I’ll hopefully be reviewing whichever of my recent games claims the most of my time, though I’ll also be on a plane.

marsy: Don’t punch your own ear

This week I learned that accidentally punching yourself in the ear a few days after getting a new piercing hurts. It hurts rather a lot actually. But hey, shiny new piercing! On a totally unrelated note, guess who has a swollen ear?

Aside from that I’ve been studying for exams, sitting exams, and playing Dragon Age. Did a run through the games to prepare myself for Inquisition, which I will probably review next week (assuming Pokemon doesn’t consume my life). I’ve run out of Dragon Age for tonight though, so I’m replaying Golden Sun (again). It’s good. Play it.

That’s all from me. marsy out.