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Parabola Theme and reCAPTCHA

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recaptcha wordpress loginToday I installed reCAPTCHA to get rid of spam. The installation was really simple and I noticed really fast that my IP Blacklist plugin had a little time to relax. But I noticed that the login page look a bit odd. I googled a bit but didn’t find anybody whit the same problem. Also nobody answered in the google group about my question. So I researched myself and found the wordpress tutorial to change your login page.

I added the following to my functions.php, just to increase the size of the login page to 400px, and voila, better.

function custom_login_size() {
        echo '<style type="text/css">#login {width: 400px;}</style>';
}
add_action('login_head', 'custom_login_size');

I hope this can help you with your problems… 🙂

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Best Time to Upload and Get Popular on 500px

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UPDATE 3: recently 500px changed the website and you cannot see the number of likes anymore…

UPDATE 2: Now i’m continuing the test, but this time with an another account and a new picture. I’ll now wait the whole 24 hours period of 500px and upload only once a day.

Test Uploads, Score of the Picture according to 500px Pulse and the absolute Views/Likes/Favorites 
Date/Time 8 am 10 am 12 am 2 pm 4 pm 6 pm 8 pm 10 pm 12 pm 2 am
Monday  88.2
166/-/22		  88.9
170/27/4		 88
199/27/9		  90.5
197/32/8		  85.1
33/19/3
Tuesday 88.3
213/22/10		 90.6
219/31/7		 63,9
42/5/2
Wednesday 91.3
363/34/9		 89.7
146/25/11		 56,6
12/4/1
Thursday  87.7
393/23/6		  87.1
123/21/8		 iP  93.0
530/43/11
Friday
Saturday
Sunday 60.1
28/5/1		  85.0
97/18/4

UPDATE: I just stopped this test, because I realized, that the users rating is influencing the tests. When I was uploading normally my pictures before, the first Like was worth about 27 Pulse, the second something around 15 and so on. Whit my test is was upload 5-6 times per day the same picture. At the last day, a Like was worth 10 Pulse! With this, my test will deliver really bad results and completely destroy me repetition on 500px. I decided to slow down this test and upload the picture not so often anymore. Maybe I will use the whole 24 hours span of 500px to get the real rating.

I’m not completely sure how the algorithm works, but according to my findings, a click on Like is not worth 27 Pulse at all time and all users. Below, the rating of three pictures can be seen. (Sorry for German… 🙂 ) All of them have the same Likes and Favorites, but different Rating. All of them are from the “New” section at the same 10 minutes. And all of them had no comments. The first one is mine.  It seems that the view to like ratio does not influence the rating that much, since the third picture hat more views but a higher score. Whats left over, is the users rating. Correct me if i’m wrong!

Rating

Since some time I’m participate on 500px.com, to share my photos and get some feedback on the composition and processing etc. My choice felt to 500px.com because I don’t want to create an Yahoo account, I simply didn’t thought about Tumblr and I hate the iPhone majority on Instagram (yes, I have a rooted Android :P). Anyway, 500px offers with the rating system an interesting way of measure the, let’s say, “Beauty” of your pictures, compositions and processing. Also you can have the pictures still with a CC license (maybe the others have this as well, donno…). After I uploaded some photos I got exited. I was spending nights with watching other photos, like them and post some comments. On the other side my pictures get a relatively good rank and some nice comments. But, for high quality critics, go somewhere else. I had some nice rating over 90 and 95 also. 500px has a nice rating system called Pulse. If you want to sell pictures, a high rating, Pulse, is recommended.

Photograph Battle of the Nations Monument in Leipzig V2 by Thomas on 500px

Battle of the Nations Monument in Leipzig V2 by Thomas on 500px

Still my best one: The Battle of the Nations Monument in Leipzig.

When the days got longer, I had some time at the golden hour and blue hour to take some pictures.  I also had a new lens and I was still exited with my new 6D. I started photographing at 5 pm and ended at 9 pm or later. After that processing the pictures was not in my mood and I left that for the next day. So i stood up, made some processing and uploaded the pictures, let’s say, between 9:00 and 9:30 (CET) in the morning, three, four days in a row. I was really surprised that the rating where just around 70-80, sometimes less. Could it be that I’m, not like I thought a little bit good, really bad at photographing?

Photograph DC Tower Vienna by Thomas on 500pxBut I was going curious. I noticed also that the count of viewers where not that high like before. OK, no views, no likes, no rating. Even the best pictures of 500px have normally a 1-to-10 rating for “likes” to views and even less with “favorite“. So I made a simply test with one of my pictures. The photo on the right is the DC Tower in Vienna. Not the greatest picture, I know but a 80 worth for sure. The first time i uploaded this picture at around 9-10 AM CET, the pulse stood still after some hours, at around 70. The second time, I uploaded at 8 PM CET. And voilà, the pulse reached 90.7. Also the views where going from some under 100 to over 400. So there are clearly some good and bad times for uploading photos to 500px.

I decided to make a test with one of my newest pictures from Vienna. Also not a very good picture, but clearly worth a 80 or 85. I will upload this picture the next weeks to different time and will not interact with 500px at all, only to see the rating and the views after 2 hours and the upload to a different time again. I started today again at 9:30 AM CET. I’ll try to update this post recently to the latest results as soon as possible.

 

Test Uploads, Score of the Picture according to 500px Pulse and the absolute views
Date/Time 8 am 10 am 12 am 2 pm 4 pm 6 pm 8 pm 10 pm 12 pm 2 am
Monday 67.0
Tuesday  84.9 86.9
Wednesday 82.1  75.9 50.2  85.2 56.4 56,6/26
Thursday 65.6/34 68,6/24  69.8/35  58,5/21
Friday  39.6/8 iP
Saturday
Sunday

 

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Clouds over Stuhleck – A HDR Time Lapse

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Recently we were going to ski at Stuhleck in Austria. Or, better my girlfriend went skiing and I went to time lapse and HDR shots… I took three time lapses and some HDR shots. Two of the videos where really nice, the third went to crap because of two reasons. First, before setting up the camera to record I didn’t check about the memory card. I recorded my footage and went with the other camera around the mountain, after I cam back I noticed the memory were full. And second, I tried to photograph trough a hole in a tree, covered in snow, to have the sun moving on the sky. Nice idea but even with HDR everything was white and blur. Also the tree was moving a lot… Anyway here are the first two lapses in one Video.

For the HDR processing I used Luminance HDR 2.4.0 and, as usual, After Effects for processing the Video. I also tried to make some processing on two pictures for uploading to 500px but the rating was poor. A single picture I have to say looks boring but the moving clouds and light on the ground looks nice in the video.

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Hyper Parliament- A Hyper Lapse of the Austrian Parliament

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Yesterday I thought, enough with work, let’s go photographing! But the questions were: what? how? After a bit of sitting around I remembered the tutorial from gwegner.de (by the way, a really good site for tutorials and information) for hyper lapses. This video is in German, but here is also a nice one in English from digitalrev.com.

Basically, with every picture you move with the camera along an imaginary line and take a picture while aiming at the same spot on every picture. As described in the videos, you should use marks are already present, like stones on the ground or just use your step span. In any case this will produce a bit shaky footage, but this can be corrected in after effect. If you shoot in the night, and the are no clouds or stars visible, like in my video, the interval between the pictures is not important. But if you have something in the screen with a steady movement, like clouds, then use a intervalometer. In this video there is a very good description of that. Anyway, in my case i was just going a step forward, point, shoot, step forward, point, shoot…. 250 times. And done. The camera settings were 3.2 s exposure, f/4.5, ISO 100.

After that you have your footage, but this is really shaky. It is impossible to align the camera and the rest completely! But for this there is Adobe After Effects, if you have money, or Deshaker for Virtual Dub, if you don’t have money or just like Open-Source. In any case, the result looks really nice. In post processing I gave to the footage a little bit of a unnatural look, so it looks like rendered, but it is actually taken with a camera in 2 hours and another 2 hours for post processing.

In this video is also stated, that u don’t need fancy equipment like tripod, intervalometer and chalk marks on the ground for 1 km. It’s worth taking a look.

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Night Sky Photography Shutter Speed Calculator

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UPDATE: I’m glad to announce that I finally found the time to release the Night Fox Android App for my Shutter Speed Calculator!

Get it on Google Play

This is the shutter speed calculator for night sky photographing. Basically you just insert the data of crop factor, the megapixel you want to archive or your camera has, the focal length and the tolerance of pixels you can accept. The description of all these different factors is below. The description of the whole process can be found here.



















Crop Factor
The crop factor is depending on your camera. It is influencing the field of view (FOV) of your camera, like the focal length also does. This calculator includes the factors 1 (3:2), 1.5 (3:2), 1.6 (3:2) and now also 2.0 (4:3). (Thx to Livio for the comment)
See also http://en.wikipedia.org/wiki/Crop_factor and http://en.wikipedia.org/wiki/Aspect_ratio_(image).

Megapixel
This is the amount of megapixels you want to achieve. It can be the maximum of your camera or also a lower Value. I included this value, because somebody may what to have the pictures not in full resolution, but a maximum of exposure time. With a smaller resolution I’m recommending to reduce the pixel tolerance as well.

Focal Length
The focal length is very important for the field of view and therefore how fast the stars are moving. The rule of thumb is “the lower the better”. But be aware of the speed of your lens. This influences the needed exposure time as well.

Pixel Tolerance
Depending on what you can live with, you can adjust this value. Basically it describes the tolerance of how many pixels a star can “move”. In some cases 20 pixels are OK, but for having really sharp stars, I recommend 10 pixel.

The Milky Way Exposure Calculator can be found here and as well as the other articles of http://www.lonelyspeck.com/.

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Karawanken Mountain Chain Time Lapse

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After New Years Eve we got an invitation for a short ski holiday trip near Klagenfurt. I was able to shot some nice time lapses from the Karawanken mountains. The clouds coming Italy seem to fall like water over the mountains. Also i go a nice day to night transition withe the moon as light source on the mountains. The day to night transition was made with LRTimelape 3. For this tool are a lot of tutorials available and the free version is more or less full featured, except that the footage is restricted to 400 pictures.

Creative Commons Lizenzvertrag
Karawanken Mountain Chain Time Lapse von Thomas leber ist lizenziert unter einer Creative Commons Namensnennung 4.0 International Lizenz.
Beruht auf dem Werk unter https://www.jamendo.com/en/track/654856/sombre.

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Vienna at Night

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After I posted the Special Shot Section of Vienna at Night, here now the normal section for the Vienna at Night shots.

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Vienna at Night – Special Shots.

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During the last year I was able to take some shots of Vienna at night. A very nice spot is the Karlskirche. With my EOS 600D I took some shots at once, but I had the problem that I had no tripod. So I took some pictures with the hand and ISO 3200. But because of the APS-C, I had a lot of noise and used the stacking technique and stacked tree pictures into one. This technique is really nice for people that have a small sensor size and also want to have low noise pictures.

Karlskirche in Vienna. Taken with EOS 600D and ISO 3200 free hand

Karlskirche in Vienna. Taken with EOS 600D and ISO 3200 free hand

I also took some HDRs of the Karlskirche an tried different setting to the algorithm. I’m not really satisfied with the Adobe Photoshop algorithm. It looks somehow false and not nice. Next time I will evaluate the programs Photomatrix from HDRsoft and also the open source alternative Luminance HDR. I’m really looking forward to test  both programs and their performance. Anyway, here are the results of Photoshop HDR after a really long time of trying. Most of the times I ended up with monochrome settings but this is also boring all the time.

The Karlskirche in Vienna. HDR Shot out of tree pictures with +- 2EV.

The Karlskirche in Vienna. HDR Shot out of tree pictures with +- 2EV.

The Karlskirche in Vienna. HDR Shot out of tree pictures with +- 2EV.

The Karlskirche in Vienna. HDR Shot out of tree pictures with +- 2EV.

I also made some HDR pictures of the Musikverein in Vienna. The main problem was that I had a bit of rain. This can be seen in the dark areas where the water drops form some halos.

Vienna Musikverein. Assembled out of three pictures with +-2EV.

I also really like long exposure photographs. They show you a surreal picture of the real world. Also they are easy to made. You just need a nice spot and a long exposure. The camera type, small sensor sizes and weak ISO performance doesn’t matter, as well as lenses with aperture numbers above the f/3. These pictures below are taken with a EOS 600D and the stock 18-55 mm IS II.

The picture below is stacked out of five pictures with ISO 100, f/22 and 10 s of exposure. The camera was the EOS 600D with the 18-55 mm IS II. I stacked the picture with Photoshop with the Bright Color mod for each layer.

Light Streaks in Vienna.

Light Streaks in Vienna.

This picture is also stacked, but i used 40 pictures for stacking. The Camera settings were f/11, ISO 200 and 2.5 s exposure.

Highway A22 near Vienna.

Highway A22 near Vienna.

The picture below is also stacked but for this I used the the Vivid Light settings. The camera settings were f/22, ISO 100 and 15 s of exposure.

Light Streaks in Vienna near Karlsplatz.

Light Streaks in Vienna at Karlsplatz.

 A normal long exposure is the picture below. This was taken with the EOS 6D and the Sigma 50 mm 1.4. I did not stack them, just used some Camera RAW Settings.

Long Exposure Capture at Liechtenwerderplatz in Vienna.

Long Exposure Capture at Liechtenwerderplatz in Vienna.

Also the following picture is not stacked, just reworked with some Camera RAW settings. This time also the camera was the EOS 6D and the Sigma 50 mm 1.4.

The Währinger Gürtel an Night.

 

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Shutter Speed Calculating for Night Sky Photographing

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Night Sky at the Alois Günther Haus

Night Sky at the Alois Günther Haus

Recently I wanted to improve my skills in night sky photographing. So I opened the PC and asked Google a lot of questions. I was reading a lot about shutter speed, focal length and exposure adjustment. A very good site I found was How to Photograph the Milky Way of the site www.lonelyspeck.com. They created a very good tutorial and answered many of my questions. They also created the Milky Way Exposure Calculator, witch lets you calculate how a lens may perform on your camera. For ranking the lenses they calculate a score, basically from the physical parameters of the lens. I agreed with the majority of the parameters, but I was wondering if the slowest possible shutter speed is maybe a bit inaccurate.

In night sky photography the shutter speed is mostly longer than 5-10 s or even more. Without a tracking device the stars will move over the sky and produce, depending on the shutter speed, streaks on the picture. But we want actually a clean image of the stars. So what we need is a lens with a short focal length and an aperture which should have less than f/2 to gather a lot of light. The basics can be checked in the links above. Anyway, the rule of thump for the shutter speed, 500/focal length, seems a bit inaccurate and, as stated there, also not completely usable for APS-C cameras. So I started to think, how can this be solved better…? I was drawing some sketches and made some calculations and concluded: there might be a better and more accurate way: I started to research about what information are available for all lenses and cameras. I concluded that the sensor size and the focal length is available in any case. The angle of view was not all the time available or I just couldn’t find it. Anyway, with the sensor size and the focal length we can calculate the angle of view with the following equation:

alpha = 2 * \arctan {\dfrac{d}{2 * f}}

In this equation, d is the diameter of the sensor and f is the effective focal length. Since f is depending on the focus, the focal length F of a 50 mm lens is only 50 mm when set to Infinity. Since in astro photography we use only the infinity setting we can assume f = F. So we can also calculate the horizontal and vertical angle of view for a lens. In this case I will just use the stock Canon EF-S 18-55mm 1:3.5-5.6 IS II on a EOS 600D with 18 MP as example. Why we need the horizontal and the vertical angle of view, will be pointed out later. With the pixel count on the camera we can now calculate the angle to pixel ratio. The 600D has 18 MP with a 3:2 ratio. This leads to a pixel count of 5.184 px by 3.456 px. The pixel to angle ratio is calculated by α / Σnpixel. The diagonal pixel count is just calculated by Pythagorean theorem.

  • Vertical AOV: αv = 27°; Pixel to Angle Radio = 0,0185°/px
  • Horizontal AOV αh = 37.4°; Pixel to Angle Radio = 0,0164°/px
  • Diagonal AOV αd = 46.8°; Pixel to Angle Radio = 0,0153°/px
The night sky can be seen as a cylinder rotating around the camera.

The night sky can be seen as a cylinder rotating around the camera.

The next assumption we make is that the sky is rotating around the world. I know that some people will now say “NO! Galileo was very clear with that!”. Yes its not true but since we focus anyway on infinity and the sky is more more less a flat area for the lens, this is ok. This lead so my next assumption. The sky is not a sphere, its like a cylinder. The picture demonstrates this assumption. The cylinder rotates with the angular speed of 360° per 24h or 0.00417 °/s. Depending on the pixel to angle ratio we can now calculate the minimum shutter speed. In case of my 18 mm focal length the numbers are very small and and seem not right.

  • Vertical max. Shutter Speed: 4.4 s
  • Horizontal max. Shutter Speed: 3.9 s
  • Diagonal max. Shutter Speed: 3.6 s

But this is only the half truth. Since the stars are not only one pixel big, we can use a threshold. For example a threshold of five pixels will give us five times the shutter speed. In my test, five pixel threshold was mostly ok and not really visible. Somebody who wants to have more clear pictures can reduce the threshold.

  • Vertical max. Shutter Speed: 22 s
  • Horizontal max. Shutter Speed: 20 s
  • Diagonal max. Shutter Speed: 18 s

I’ll program a calculator using javascript in the near future and upload it to this website. Stay tuned!