Showing posts with label astronomy. Show all posts
Showing posts with label astronomy. Show all posts

Thursday, November 21, 2019

Ave…

The weather is getting colder here, as well as my heart along the way I presume. It would have been such good news and feeling, if not for the passing of a dear online friend that suffered from a long battle against diabetes. Though we never met really, but we still shared all the jokes and laughter together and she was quite fond of my photos. She dreamed that one day we might meet up in Ireland and even do some photography in front of her. She made me feel as if my photos from Ireland made her re-discover her homeland; As if she was not Irish already, living her final days in the US.

Rest In Peace, Paula Doak


Mearcair

Last week the news were out about a transit of Mercury over the disk of the sun. Not a rare event but it definitely is not the average event that would happen every year. I think the next transit for Mercury of this sort might take place in 2032 or sometime around that if I'm not mistaken, and I'm not sure even if it would still be visible in the sky here. Rarely even more than Mercury, are Venus transits. I think the next transit won't be happening in my life time at all!
Anyway, the adventure was set on Tuesday. I had a very limited time to prepare for the shoot as the transit would occur only at about 3:30 p.m. local time, and then in about one hour the sunset would officially start. To gain some time, I've actually prepared my gear the day before and made everything ready, so all I had to do is pick up the gear and head to the roof of my house. I still had some fears back then that some objects would block the view as the sun goes down in the sky but luckily none of that happened. So, in a nutshell, my gear was composed of:
  • My modified Canon EOS 7D.
  • Solar filter.
  • Rokinon 800mm Mirror Lens (fixed at f/8).
  • Flexible cable (will explain why below).
  • Cable remote.
  • Tripod of course, with ball head for easy and quick movement.
I had to refer back to my old tripod which I didn't use quite a while mainly because it extends quite high compared to my other most-used tripod, without needing to raise the central column or the neck.

The gear I used and you can see the cable around the mirror lens,
while the clips hold the solar filter over the lens front.
The shot was out of focus because the flies were really, really, really annoying.
Yes, that much annoying that I couldn't focus properly with my phone.


I was reluctant to use my old mirror lens with its cumbersome control mechanism; Just a complete manual lens with a primitive telescopic design crammed in a small volume. However, knowing that Mercury will be such a small dot over the sun disk, I've realized (and I've done my own research as well) that I do need a very long focal length, and here I had two choices. Either:
  1. Use my Sigma 70-300mm with teleconverters, OR,
  2. Use my Rokinon 800mm Mirror Lens.
Rokinon 800mm Mirror Lens f/8
Comparing the two, the scale tilts towards the Mirror Lens further. Because using teleconverters would reduce the light quality further (beside using a solar filter here) and this might not be such a good idea and the overall size of the whole lens/teleconverter combination would be too long and I'm sure it would give me some hard time in movement (specially with my external telephoto lens sleeve which is not quite as flexible as a regular sleeve on a real telephoto lens). Adding one teleconverter to my Sigma lens at 300mm would extend the focal length to 600mm. Adding another one would make this jump to 1200mm. Juicy! However, my previous experiences in shooting the sun with such a long focal length were quite cumbersome specially when it comes to moving tiny amounts of degrees to follow the sun (remember: the more you zoom in, the faster the celestial body will virtually move). So, imagine here that I'm jumping to 800mm with a single lens only and without much light quality loss; As simple as that.
Now, we come to the story of the cable. Since the focusing with such long focal length and cumbersome mechanism would prove to be a challenge, I got myself these multi-purpose bending cables or wires long time ago solely for this purpose; To wrap them around the focusing ring of the mirror lens and use it as a level to move the focusing ring gently. It didn't stop the shake though but it was quite useful nevertheless.

Mercury, after processing the image (cropped).
The lower right line is just some dirt.


Anyway, my main aim was to shoot a series of shots of Mercury crossing the sun disk but unfortunately after one hour of shooting or so, I just got plenty of images with the position of Mercury almost not moving. After being attacked by flies and sweating waterfalls I had to get inside and stop the whole thing (at that point it was past 4 p.m., and still didn't have lunch then!). So, technically, despite the many many images I've shot, I didn't quite get a serial sequence after all. Probably one of the mistakes that I've committed here is that I've focus on the sun (by checking the edges of the circle on LiveView of course) thinking that because of the great distance between Earth and the sun, Mercury would virtually be in focus as well. This seems to be not the case here though! When I've edited the images, Mercury was not quite that sharp dot on the disk of the sun, but more like a blot of ink!

100% Crop of one of the images. Mercury is the small black dot,
which I think it could have been more in focus. In some images, Mercury
completely disappears.
(click to enlarge)

What amazed though is the presence of dirt and other artifacts. I thought first that those are only on the solar filter from the outside but it turned out to be they are sensor artifacts. This is despite cleaning the gear (lens and camera) the day before and making sure all are clean (and using the loupe to check the sensor specifically). I'm not sure how this got in, but definitely I need to check and clean it later. Didn't have time to do so yet.
At this point, my little "silly" adventure with Mercury transit was over and I'm still checking the images Ivé shot (counted more than 2400 images) to see if I can do anything artistic about them! We'll see.

Finale

The departure of a friend, an online friend, is not in any way less drastic than a real physical friend's departure; Whether met or not. This departure was sudden to me, because she was supposed to be coping well with her new condition after amputating one of her legs because of some blood problems. Such a drastic and sudden change of events.
All these feelings actually are pushing me to write emotionally from the first moment I've heard the news, and typing an eulogy on her feed on Facebook. Now, I feel the urge and the necessity to really focus to write one poem at least for her sake.
All these ideas seem to clash now in my head though. I do have other tasks and other ideas of photography that I want to work on. One might consider typing or writing a poem is easy but that's not really the case at all. It needs dedication and time, and foremost, an immersion into your own feelings. Now my feelings are there hovering in the air as well as my words, but I have to turn my mind into a lens to focus these into proper and rhyming words on paper (or monitor that is). Goodbye Paula. May we see each other one more time, in peace…


Thursday, May 2, 2019

AstroFails - Reflections…

It has been a semi-idle week. I had many hopes but they were crushed down; Regarding astrophotography that is. However, I might keep trying after a while, but right now I need to focus more on some ideas I'm trying to achieve and do for a while but I was simply lazy to do. What I liked about my trials with astrophotography is the fact that I can do it at home just in the yard and I can have a decent time alone even when everyone is inside the house. Reminds me of that time when I used to climb up to the highest point on the roof just to shoot the cityscape of my area from there or do time lapses for the sunset. Unfortunately though for me now, I can't go to the roof, and in the yard, my field of vision for the sky is limited by the surrounding houses which somehow limits my good view to the zenith above me alone. But that's another story anyway. Yet, I will post here some of my failures with astrophotography, which is still under studying and learning processes.
Before heading to my failures in astrophotography, I'd just like to list here my results certificate from Treierenberg Circuit, which was emailed to me on April 19th. I wouldn't call it a success, nor a complete failure, but I was hoping for more brilliants results than this actually.

A=Accepted, R=Rejected (for exhibition).
Click to enlarge.
 First of all, if you have OCD please don't look at the list because I didn't have the time to organize it with my copy/paste process! It bothers me as well but I have to do with this right now. As you can see from the list, lot of images were rejected (and some of them were kind of unexpectedly rejected). However, I'm happy that my first time with "Series" photography, entitled Syrian Girl, was accepted; All five images. This series was shot some time ago (I think in 2017) for a project with the group which I was a member in back then, and it was not really dedicated to the topic of a Syrian girl at all, but was more general about how a girl would remain a girl even in adulthood. But somehow the meaning can be twisted as well to reflect the status of a girl, who lost her parents in war.
Anyway, no gold medals this time, but I'm happy that my shot Anxiety got accepted. I can't post all images here but probably you can roll back to my previous posts where I posted some of these images (and I made a quick video as well for one of the posts).


AstroFails

As I've mentioned earlier, my trials with astrophotography from the yard at home were prone to fail mostly and I couldn't catch but a glimpse of some constellations or stars. My real target, though, is to shoot something exciting like a nebula or a galaxy.
In the course of learning, I had my hopes up for various reasons, as well as learning many other aspects that might be beneficial for the photographic vision and processing as a whole later on. Specifically, the power of RawTherapee! I still have my hopes high despite the failures that I've had already. I've read and still reading from time to time about the trials of many people in shooting high ISO and in the city bringing the space to life with their images, without even using a tracking mount which typical for a serious professional astrophogoraphy, Despite following their steps, I didn't come up with anything serious though and I guess it's all laid on my own problems with the location and gear.

A trial with 50mm lens on April 21st. Probably Leo constellation appears here.
The black spots are probably passing clouds or just stacking artifacts.
So far, I didn't exceed the limits of shooting constellations only, even with the range of 300mm, which I've read in some pages that it is fine for astrophotography. The downside though of using my 300mm lens (Sigma's) is the small diameter compared to more professional photo lenses (62mm) and the high f-number (f/5.6 @300mm) which limits the passage of light (specially faint beams) even while shooting in high ISO. Using my Rokinon mirror lens is of course out question here (but I tried it anyway!); The lens if 800mm but with a fixed aperture of f/8. A catastrophe even with high ISO. But I like to imagine how the situation would be if I would be using a tracker with this lens? Then I would be able to shoot for a longer time and would for sure collect more data and more light!

Trial at 100mm on April 23rd with Hα filter. Unfortunately,
I couldn't work out what constellations are present here. I've spent hours trying to check
star maps! If you can help, please feel free to comment below.

My trials in the beginning were always at 300mm with Hα filter to suppress the light pollution. However, reading more about the topic, I've realized that most professionals would shoot normal, without such a filter, even in untracked astrophotography like what I'm doing right here, and shoot Hα to collect more data in that region of the spectrum and merge it with the normal images. It's easy to be done digitally, complicated to be done in practice! However, I've shot with the filter and processed some images and some of them yielded some good results with Deep Sky Stacker (DSS). Seeing how things are hard with 300mm, I've decided to go all the way to the beginning; Shooting with 50mm, then 100mm and then maybe 200mm and 300mm. My trials are still going on while typing these words actually but I've stopped for some time to do other photography projects on the side!
This experience in shooting astrophotography, despite its failures, as I think, did teach a number of things and opened my eyes to another venue. I like to organize my thoughts in points here:
  • Shooting with high ISO: I'm not afraid to crank the ISO to its highest point. Not only in astrophotography but it could be in other genres as well. A number of things had changed when it comes to dealing with such images and such noise.
  • RawTherapee: It turns out, beside DSS, that this open source editor would be (and is) the best friend one can have away from Photoshop! The noise reduction algorithms and the capabilities of adding a dark frame and a flat frame to the algorithm of noise reduction and image correction makes it ideal. This is beside the "demosaicing" algorithms, of which two are dedicated to high ISO images. I'm thinking seriously of visiting some of the old images I've taken (specially those from 2015 from the Monodrama festival back then) and try to reduce the noise with RawTherapee. Some professionals, as I've read in some articles, make a point that it's bad that RawTherapee does not allow the addition of more than one dark frame to take the average for noise reduction (like DSS does) but I think this is something specific to DSS and the nature of astrophotography, and RawTherapee is a general editor of some sort and should not necessarily go on the same path as DSS. Another good point for RawTherapee is the ability to work with 32-bit images as well (HDRs), and in various algorithms as it seems (linear and rational).
  • Ball Heads: I never imagined that my worst enemy in shooting would one day be my best friend in shooting! When I started my trials with astrophotography, I used a panning head; My preferred head to work with ease. I've neglected all the advice I've read about using ball heads in those online articles from professionals. I was wrong, completely. Ball heads in this situation IS the real and the only candidate for shooting the sky. Thinking about it, I might even consider integrating such a head in my usual workflow (but not in panorama making for sure of course).
Probably these are the major points that changed or added to my knowledge about photography and my usual workflow in processing images after shooting. At this time, I'm still trying to cope and enhance my practical workflow when shooting the sky but I have to admit that I didn't achieve much progress in that arena. Here are some of the problems that I'm still trying to find solutions to:
  • Focusing: Having a good focus to a completely dark sky with unseen stars (until the images are processed) is quite a struggle. I've been even taking test shots just to notice and see if there are any bright stars in the image and move the focusing ring accordingly. Reading articles online about this matter did not help much, and applying the principle of the hyperfocal distance is not achievable somewhat (specially when the f-number is quite low). Probably the most significant advice I've seen online is to focus at some light source or a subject which is around 100m away or so, and that is not possible to do in my case (I don't have such a space as I'm shooting at home).
  • Locating: Currently, I've been using an app on my Huawei android phone called Sky Map, and probably this is the best I could find. The app is fine, but the problem is in matching the field of view on the phone with that of the lens (i.e. what does the lens see). The lens' field of view is a measurable angle (according to the sensor size), but on the app there is no scale for that. I tried to check for a better app but seems this is the best I could get so far. 
  • Pointing: With the problem of locating, comes the other problem of pointing in the right direction into the dark sky. A cumbersome method I've came up with is to hold my phone against the LCD of my camera (as if it is the LCD itself) and look at the map on the phone to know what stars are in view. This is not an accurate method of course but maybe a good approximation. Moving the camera cannot be done while holding the phone against the LCD, unless with some help (but I'm working alone here, as usual).
  • Tracking: The method of "untracked astrophotography" depends on moving the camera manually and follow up the movement of the object in the sky. But the sky is dark already and I'm not sure how would I follow up an object that cannot be seen even on LCD when the shots are taken! For this, I depend on some visible clues like a glittering little star and check its movement before changing the orientation of the camera. However, maybe this star is not anywhere near my original aim in the sky!
  • Gear: Not talking about a tracker mount (which is favorable actually), but a good lens would do wonders. In the images above, shot at 50mm and 100mm, all were actually taken with my Canon EF 50mm f/1.4 USM lens, with just the addition of a 2x teleconverter to reach 100mm (and adding another one to reach 200mm even). Teleconverters double the focal lengths AND the aperture. Thus, f/1.4 would naturally go up to f/2.8 (and surprisingly stops at this value even when adding another teleconverter). Most of the articles I've read online talk about Canon's 70-200mm lenses with f/2.8 and adding a teleconverter to that to reach 400mm to shoot nebulae and galaxies. Makes me really wonder whether my Sigma 70-300mm is any good to the task with its f/4 at 70mm and f/5.6 at 300mm (and adding a teleconverter would raise that up to f/11 at 600mm!). Baseline: f/4 is not good enough. But anyway, I'm willing to try my best still with what I have.

Those are, probably, the most dominant problems in my work with the sky so far. I'm willing to try and try again. For the time being, I'm just having a break to type this blog post and also to work on side projects (which, again, starts with chasing my gear around and locating lost items). I was hoping though to get some decent results for a galaxy or a nebula, and start typing an Arabic blog post about my experience with it. Guess this has to wait till I get concrete results. I am aiming also to take wide angle shots and try to catch the milky way in such light-polluted area, so I might leave the comfort of my home or try to reach the roof. We'll see about that.

Finale

Summer is arriving here and the weather is getting hotter and hotter. It's such a mess in my workplace right now, and such a mess in my brain right now. The idea of just resigning and leaving everything behind me really tickles my brain from time to time. I really need some kind of eternal rest, from useless routines and work, and people as well. Is that a result of not traveling for such a long time? Maybe. Not sure if I will travel this year though despite having some ideas already. The laws here, also, are getting up to some ridiculous degree, and around me I see many people and instances of people trying to survive in this turmoil of a thing that is supposed to be a homeland.
Meanwhile, I'm looking at my poetry writing and I feel sorry for myself for not being able to write down anything or do anything about it for months now. It feels if my soul, rather than my body, that is so tired deep inside. Tired of everything. Tired of even pinning a smile on my face wherever I go and keeping my cool temper. All that is blocking my way of expression, verbally, and in writing. All I'm wishing for right now is to have the mood and power to work with my camera as much as possible and trying to put my mind off the problems that hover around me…