Round 3: Canon 100-400mm @ 400mm vs. Canon 200mm 2.8 with Kenko 2x

Canon 450D at ISO 200, two lenses were tested again each others namely, both lenses are having date code beginning with UW:

1. Canon 100-400mm f4.5-5.6L USM
2. Canon 200mm f2.8L USM + Kenko 2x

Zoom at f5.6, center cropped:-


Zoom at f5.6, border cropped:-


200mm with 2x at f5.6, center cropped:-


200mm with 2x at f5.6, border cropped:-


Zoom at f8, center cropped:-


Zoom at f8, border cropped:-


200mm with 2x at f8, center cropped:-


200mm with 2x at f8, border cropped:-


Summary: center sharpness of the prime with 2x is similar to that of the zoom, but the border sharpness of the zoom is clearly superior!

Final test on the sun with Thousand Oaks Type 2+ Glass filter, all cropped:

200mm with 2x wide open:-


100-400mm at 400mm wide open:-


The one from the zoom has a more well defined edge, it could be a result of the IS of the zoom but from my previous experience, even when I put the 200mm with 2x on a tracking mount, the edge is still a kind of fuzzy, so it's very probably that the zoom is performing better indeed. More tests should follow.

Round 2: Canon 100-400mm @ 200mm vs. Canon 200mm 2.8

Canon 450D at ISO 200, two lenses were tested again each others namely, both lenses are having date code beginning with UW:

1. Canon 100-400mm f4.5-5.6L USM
2. Canon 200mm f2.8L USM

Zoom at f/5 center cropped:-


Zoom at f/5 border cropped:-


Prime at f/5 center cropped:-


Prime at f/5 border cropped:-



Zoom at f/8 center cropped:-


Zoom at f/8 border cropped:-


Prime at f/8 center cropped:-


Prime at f/8 border cropped:-


Finally, let's see the prime at wide open (f/2.8), and you will know it's an exceptionally good lens!

Center cropped:


Border cropped:-


No doubt that the 200mm f2.8L is always recommended for astrophotography.

Round 1: Canon 100-400mm @ 100mm vs. Canon 100mm 2.0

Canon 450D at ISO 200, two lenses were tested again each others namely:

1. Canon 100-400mm f4.5-5.6L USM
2. Canon 100mm f2.0 USM

So here are the testing shots at f/4.5:-

Prime at f/4.5 resized:-


Zoom at f/4.5 resized:-


Prime at f/4.5 center cropped:-


Prime at f/4.5 border cropped:-


Zoom at f/4.5 center cropped:-


Zoom at f/4.5 border cropped:-


And then the test shots at f/8:-

Zoom at f/8 resized:-


Prime at f/8 resized:-


Zoom at f/8, center cropped:-


Zoom at f/8, border cropped:-


Prime at f/8, center cropped:-


Prime at f/8, border cropped:-


Finally, prime at f/2:-

Center cropped:-


Border cropped:-


Resized:-


The 100mm f2.0 is recommended for astrophotography in a number of website, I guess that I have to stop it down to f2.5 or slower and considering the price and versatility, it's unbeatable.

20090716 Jupiter

Finally, I got it. It's hanging outside now but it's rather low in the sky, I should have waken up earlier. Anyway. It's pretty cloudy essential but I did try.

Sky: Seeing 4/10, transparency 0-8/10.
Telescope: Orion 100mm ED f/9
Camera: DMK 31AF03.AS
Barlows: Tele Vue Powermate 5x
Mount: Meade LXD55

First of all, I pulled out my Pentax 40mm SMC XL to center the ball in the field, hey it's oh-so-sharp! There are so many stars in the background sky but the brightest ball is too bright to see. Those satellites were nicely and equally separated, two at each side. Great view indeed. Then, I inserted my Japanese 7mm Ortho there...

Wow!!!!

What a view! Plain sharp! GRS is right in the face and I could see so much detail! This is one of the best view of Jupiter that I ever had! Impressive! I guess part of the reason is owing to the fact that I didn't see Jupiter for very long! And another part of the reason is the refractor view... It's just another story when compared to SCT, period. Bigger aperture really helps, but quality aperture also counts. :-) Don't beat me if you don't agree, just enjoy your own view as much as I enjoyed mine.

Then I pulled out my DMK... at prime focus first... it's just cute!

0439 (GMT+8), all the satellites in place!


Then I inserted the 5x, but then cloud rolled in, and it keeps rolling in... anyway, I have several 400 frames AVIs (I usually get 1000 at 30fps) between those nasty cloudy, so far when I am typing this, the view is still totally covered.

(After processing, I found those smaller AVIs are all bad due to the variation of cloud thickness and sky condition)

And just before the sky turned blue, I managed to get a much bigger cloud gap. See what can I get. I couldn't do very critical focusing because time is running short, so I just took two clips with slightly different focus position. See my luck and my guts feeling about correct focus this time.

0505 (GMT+8):-


0507 (GMT+8):-


Which one is better in your eyes?


I am going to try out my 450D in video mode next time when I got more time.

Canon 100-400mm f4.5-5.6L

Just got it today! It's kind of unexpected, anyway, it's a UW model. I will try to compare it with my Canon 200mm f2.8L with a Kenko 2x very soon.

This zoom should be far more flexible, and at the same time, it has IS which is great for daily purpose. For astronomy, the Canon 200mm f2.8L should be better since it could be used wide open. The Kenko 2x is more useful for solar eclipse trip before, and now I guess maybe the Canon 100-400mm f4.5-5.6L can replace it entirely. But of course, I shall try it out first.

So if you're interested in the comparison between this two options at 400mm f5.6, stay tuned.

20090715 Sun

The weather is funny today, sunshine and heavy rain alternatively, I took the chance of the perfect sunshine and captured a few shots. As usual, taken with my Ranger/Solarmx40 and BF10/DMK 31AF03.

1523-1524 (GMT+8), two frames stitched together:-


1525 (GMT+8):-


I also took time to enhance my Baader filter for my Canon 10x30 IS and test it again, it fits much better now. I remember last year I dare not to let other people to use it since I don't feel it safe, cannot risk other people's eyes... I have to hold the filter bracket with my fingers and it's hard to teach other how to do it. Now, it's ready for the upcoming partial solar eclipse here. There's no sunspot in white light.

Equipment line-up for upcoming solar eclipse

This is a plan for local observation, i.e. a partial eclipse.

1. For friends and passerby, I will prepare two sets of eclipse glasses.

I will also use my Canon 10x30 IS with Baader filter. I will need to make a better mount for the filter since it could be dangerous for the present one.

2. For photography:

- White light: Canon 450D + Kenko 2x + Canon 200mm f2.8L with Thousand Oaks filter, controlled using timer release automatically after the first contact and I will take exposure every 5 minutes.

- H-alpha: Ranger with reducer + Solarmax 40 with BF10 + DMK 31AF03, target for first contact plus a few shots in between the partial eclipse, maybe every 10 minutes and then let people look through it in between the exposures. Each sub-frame should have around 300 frames only to save disk space and time.

- Mount: my TG-SP II should be good enough but I might take my LXD55 for stability

- Power: My notebook would need that 12V SLA, and the DMK would also draw power there via a powered 1394 hubs.

--

If I were to travel, I will only bring the white light setup on TG-SP II, and also my Canon 10x30 IS like the last year.

Stellarium

http://www.stellarium.org/

I found this one very nice and easy to use, no more those useless manual to block your view, and the simulated view is just fantastic. Not too real to confuse newbies like the real sky (!), and not too fake to become useless.

Best of all, it works very nicely and it's free.

20090714 Sun

No transparency that we can speak of today, it's 0.1/10 if I were to rate it. Just for fun, two frames stitched together, zero detail absolutely.

Upcoming solar eclipse

I have no concrete plan yet, but since there is no place like last year, that is, a place where good weather is nearly a certainty, I didn't plan for a trip yet. And this year, the eclipse path covers big cities so that air ticket is easy to get and we can easily get there without too much travelling, so we can wait until the last minute for a quick two-days return trip.

Here is a list of factors for my considerations:

1. Weather forecast: this is the single most important thing, and so far, those easily accessible locations only got cloudy, raining or even thunderstorm. So, it's better to wait until early next week?

2. Location: since most of the locations are big city, the good thing is the transportation, but the bad thing will be a "weaker" solar eclipse due to air pollution, the most beautiful thing about solar eclipse is the huge dynamic range of detail, but then air pollution will kill contrast like hell.

Frankly, I'm kind of worrying that this solar eclipse might kill people's appetite.

Finally, there's one more less important factor and it's about equipment. Last year, I planned to shot via H-alpha filter during the first contact, I hope to see the moon cuts into some prominences, and I never saw similar photograph before. And I believe it would be interesting. However, I gave up since it's hard to bring too much equipment with me. Guess what, this photograph is do-able without totality, and I can stay in Hong Kong to do that! Therefore, if the local weather forecast is favorable, I might just stay in Hong Kong for that reason. Save the trouble to travel and risk the bad weather else where.

20090713 Sun

Basically featureless, Tele Vue Ranger, Solarmax 40 with BF10, DMK 31AF03 at prime focus, tracked by Meade LXD55.



Created with drift and expand method.

20090710 Sun

Typhoon is coming, transparency dropped crazily today and I don't even need a ND3 for imaging with a Herschel wedge. All I used was a green filter plus a polarizer. First up are a few H-alpha images taken with my Solarmax 40/BF10, and then some shots taken with my APM Herschel wedge.

1523 (GMT+8), taken at prime focus of my Ranger:-

1526 (GMT+8), with 2x barlows:-

1535 (GMT+8), white light using green filter and half-polarizer:-


After that, I pulled out my Orion 100mm ED f/9 for some test shots. I have to move my mount to another window to gain access to the sun, but part of the aperture was still blocked, and I couldn't use my DMK as well due to the distant from my PC. I have used my Canon 450D instead, Tele Vue 5x was used:-



Single shot cropped.

20090709 Sun - Color Experiment (cont)

This is to continue the experiment yesterday, one more data point before the sunspot goes away. Same equipments:

Blue filter:-


Green filter:-


It seems like that green is superior, but the difference is not too much. However, I guess that's enough for me to stick with green from now on.

Transparency remains high today, many local amateurs comment that the moon was brightest these days among these months (maybe years). Frankly, I never felt hot when I'm trying to point my Ranger on the sun, but yesterday and today, I really felt the heat! I pulled out a piece of paper and it burns within 3 seconds, this was never the case from my experience. The heat sink on my Herschel wedge is now more useful than before, I never feel the need to have it there before.

Comparison of white light images taken with different color filters

Date: 2009-07-08 (Around 1400-1440@GMT+8)

Telescope: Tele Vue Ranger 70mm f/6.8 ED refractor
Filter: APM Herschel Wedge plus B+W ND3
Barlows: Tele Vue Powermate 5x
Camera: DMK 31AF03
Mount: Meade LXD55

In addition to the above, different color filters were used, they include:

1. Yellow filter from Antares #12 (Japan) - exposure 1/1000s


2. Blue filter from Zhitong #38A (China) - exposure 1/108s


3. Green filter from Zhitong #58 (China) - exposure 1/45s


4. Red filter from Zhitong #25A (China) - exposure 1/736s



Registax V5 is used for the stacking job, MAP were used with 3 alignment points, around 1200 frames were captured for each individual AVI.

I guess we will agree that the blue and green ones are better of the batch, so I took two more clips for comparison:-

Green:-


Blue:-


Finally, I have briefly compared the eyepiece view with #58 (Green) and #38A (Blue), the amount of detail is similar through both filters, but I prefer the dimmr view from the green filter. Visually, dimmer view could be more pleasing but photographically, I tend to believe that my blue filter has a slight edge here, since it allows faster shutter to freeze poor day time atmospheric seeing.

Of course, we need more experiments to confirm since day time seeing tend to vary quite a lot, even among experiments taken a few minutes apart and thus, sharper result could be a just result of momentarily better seeing, and thus might not be fully a result of better filter.

My main eyepiece box

After equipment re-organizations, here is my main eyepiece box. It consists of a 40mm Pentax SMC XL, a 13mm Tele Vue Nagler Type 6, a 0.5x Siebert optics binoviewer corrector, a 20mm Japanese Widescan Type III, a Tele Vue 5x Powermate, a 7mm Japanese Orthoscopics, a 1.25" thread extension tube, a Tele Vue 2x Barlows.

The Pentax is my wide field scanning eyepiece, it also serves as my finder eyepiece.

The Widescan is parfocal with my DMK as well as ToUCam Pro, good for target centering as well as rough initial focus.

The 13mm Nagler is my main observation eyepiece, once the target is located, I will switch to this one, excellent for deep sky observing, solar observing and lunar observations.

The 7mm Ortho is my planetary eyepiece, it is just excellent, super sharp and contrasty.

Visual observation in the urban center

Don't call me crazy, it's do-able. Scorpius is hanging outside, the moon is very bright today. Guess what, it implies that the transparency is very high! So I pulled out my Orion 100mm f/9 ED to have some scanning with my Pentax SMC XL 40mm...

Once I located something interesting, I will use my Nagler Type 6 13mm. You know, 13mm is really a magical focal length, it gives wonderful view indeed. M6 is superb, and M7 is fantastic... you will know why they got their names... amazing! Refractor view is really wonderful.

I tried to locate M4, and I know it's a very hard target in urban sky... I tried to locate it before with a C8 but failed. But then I tried to see it in darker sky with my 70mm Ranger and it's just so easy... I tried again this time with my 100mm and I did it this time. With the 40mm, I know it should be there but it is not. Pushing up with a 13mm, it's there really! Adding a 2x barlows helps a little bit further by darkening the sky. Very nice! Who said M4 is not detectable in urban sky! We got the moon tonight too! Patience is the king, just keep trying...

20090707 Sun (AR1024)

Seeing 5/10, transparency 7/10. Tele Vue Ranger, DMK 31AF03.AS tracked by Meade LXD55. White light taken with APM Herschel Wedge, also with B+W ND3, (polarizer or green filter or 52mm aperture IR filter), H-alpha taken with Solarmax 40 with BF10.

1426 (GMT+8):-


1429 (GMT+8) with 5x:-


1439 (GMT+8), with green filter:-

1442 (GMT+8), without green filter:-
The one with IR pass is very bad, I guess IR is more affected by poor seeing... and maybe green is the least affected? The green filter really helped a lot to push the detail.

Jupiter... I did try!

I really tried this morning despite it's pretty cloudy. It's so bright that it's just too attractive. I setup my mount, adjusted the mounting plate... but cloud stopped me from taking any image. Actually, I even failed to focus properly since cloud kept covering my view.

I will keep trying and at least I should have taken an image after the summer!