Wednesday, September 07, 2011

If the rain comes they run and hide their heads...

I cribbed the blog title of course from what has been called The Beatles' finest B-side. It's the first line of the song 'Rain' for anyone who doesn't know it (Shame on you).

It seemed apt as the weather here in darkest Kent U.K. over the past few days has been just that. 
"Run and hide their heads" however, is less pertinent because I wanted to feature a Horsefly that was doing just the opposite one morning when I went out on my early (and rainy) walk.

It was sitting in the open and was either cold due to the time of day and inclement weather, or, had been asleep.
These big flies have fantastic eyes but the females are known to administer a very painful bite-and so it's not too often that I get a chance to photograph one that seems docile and poses little threat (hopefully).

I've also been toying with the idea of doing some 'image-stacking' for sometime and thought this'd make for a superb subject.

I had the 100mm macro lens on the camera and just to make things even more difficult (macro can be taxing at the best of times, throw in low light levels and it becomes even harder to obtain decent images), I found the  Raynox DCR-250 in my camera bag and added that to the macro to increase magnification. No tripod or monopod and so hand-held was the only real option. The insect was too high up to kneel down or brace myself against anything. I took this first shot.

Click on any picture for an enlarged version.

This was just a single frame/exposure and although the light isn't brilliant, or all that even, for a dull and rainy morning it could be worse!
I took a few more similar photographs and then had the bright idea (no pun intended) of enhancing the light by holding a small, makeshift reflector underneath the insect; or at least, as far underneath the insect as it would allow without wanting to annoy her!

This second photo is the result of that-as you can see, there's not too much difference other than the reflector was in shot, hence the lighter background to this shot. It has removed some of the darker areas at the bottom of the eyes to be fair; trying to balance everything wasn't fun though..

Image stacking for macro purposes can be used as a tool to increase depth of field; a problem that we all suffer from. That is, by being so close to the subject being photographed, there is very little depth of field. Hence, almost inevitably, some part of the image will be out of focus.

To try and overcome this problem, it's possible with digital photography to take a whole series of shots from a single position focusing on a different part of the subject with each fresh exposure. Perhaps, closest to the camera for the first shot ending up with the last frame being farthest from the camera.

Then using software, the images are combined, or 'stacked' in order to form one final photograph that should have everything in focus. Well that's the (simplified) theory! Depending on which software is chosen for the job, it can be a little forgiving of any slight movement but really it's a sturdy tripod and focusing-rail job for best results.

I've already mentioned I didn't have a tripod with me (in fact, I don't even own a decent one!) and so my only choice was to try a hand-held series of shots. I've seen some photos done this way and it can be achieved, armed with some previous advice from a 'flickr' contact (you know who you are) I tried for a series of around 8-10 shots. As far as I could tell by reviewing them on the camera's screen, they didn't seem too far off the mark.

WRONG!  Well I know now that I've tried to stack those images that they weren't good enough for several reasons. It seems to me looking at the resulting photograph that the main one is the lack of good lighting that has culminated in a lot of 'noise' spoiling the image. Possibly the alignment isn't actually all that bad for a first attempt?

8 image stack
Whilst there is quite a lot more of the image in focus, more frames would have made such a difference. I'm not even sure that the detail is that much better either than the photo below that is a straight crop from a single-exposure photo taken at the same time?

Cropped from a single exposure

However, hindsight is a wonderful thing and at the time I felt it was worth a shot at say, 30 frames to try and get a nice, smooth transition between shots. I braced my arms tightly to my sides and got into position, all the time the rain was still falling, agreed, not as hard now but just to make me feel a complete idiot for even attempting photography in these conditions, the wind began to howl too. If this is beginning to sound like a poor excuse for a poor result, you could be right but what the hell; in for a penny in for a pound as the old saying goes.

I managed 27 shots before giving in to the conditions and my aching arms. Once again I reviewed my handy-work on the camera's screen.
Hmmm.... looked reasonable but then how often have I thought the very same thought, only to get home, download the images and view them on the P.C. only to be disappointed?

The software and my ageing P.C. took quite a while to process the 27 images and even before  I had loaded them I realised that the chances of an acceptable resulting picture at the end of it all was, well, let's say less than certain. 

Admittedly I only have free software for this operation and there are (much) better programmes available but even if I had available funds, I wouldn't want to invest in something until I knew that stacking would be something I'd take to and do on a regular basis. Moreover, even the best software is unable to cope with my amateur attempts at providing sensible raw materials to work with.

And so here it is then, my hugely disappointing first real attempt at a 'proper' stack! 

As you can see, the lighting is awful and one-sided, the frames aren't aligned correctly and the whole thing looks a bit of a mess. By the way, I didn't use the full 27 shots in the end.
As usual I had jumped in at the deep end before learning to swim. What have I learned? Well, not to be so adventurous in future. Get back to basics before attempting anything as ridiculous as this again and try not to ignore the basic rules of image stacking. 

I share this with you all in the hope that it will prompt anyone with greater knowledge than I (stop it) to offer advice/solutions and general criticism to aid any further excursions into 'stack-land'. 

Until the next time then...

1 comment:

  1. Looks like a pretty good first try to me! :)


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