Sunday, June 27, 2010

Infrared Photography; Supplemental Post - Photography with Imre - Episodes 23 and 24

I figured I'd take a quick break and write up the post for the two infrared photography videos (episode 23 and episode 24). This topic is by no means a small one, so as you saw in the video I really honed in on shooting with "regular" cameras, meaning non-IR modified, using IR filters. I would say that if you're new to infrared photography, then this is a good way to gain some experience without spending too much money. Of course if you take a liking to the realm of red, then there are lots of options to take this niche further.

If it's one piece of information I couldn't find, it's in regard to at what frequency the IR blocking filter on the sensor cuts out. As you saw in the video my E-P2 could pick up the remote control's IR "beam", but I wonder where the limit is. I'm guessing it's around 720nm, but perhaps I didn't look hard enough or this is some sort of manufacturer secret as it may be used to somehow enhance the quality of the photos the camera takes. Hmm... On the other hand, a sensor without an IR blocking filter seems to have a limit around 1,100nm (see Luminous Landscape website link below).

Now if by chance you're wondering why someone would go to the trouble and potentially expense to modify their camera or purchase an IR version, there are some very good reasons. To begin with, let's quickly examine some of the cons of using an IR filter:
  • Extra piece of very dark glass in front of your lens; forces use of long exposures; potential for flaring or minor loss of image quality
  • Long exposures increase the amount of noise in a photo; depending on the camera, this may or may not be an issue
  • Quality of filter matters; some may not cut out all visible light (although this isn't necessarily bad, as for example the Hoya R72 allows some very deep reds through and I'm thinking this could improve the image quality because an unmodded camera will definitely capture the visible light frequency dark reds at the very least)
  • Takes more time to setup and take some shots as IR filter needs to be placed on or removed from the lens
  • Long exposures mean you'll have to carry around and use a tripod
On the other hand, using an IR filter is probably the least expensive route and you can still get decent results using unmodified cameras.

At this point you're probably starting to see the pros of an IR modified camera and by the way, there are different types of modifications; removal of the IR blocking filter and removal of IR blocking filter and replacing it with an IR filter (over the sensor). At this point I recommend you check out some of the links I've posted below to discover the reasons for each type of modification. So in short, here are some pros of modified cameras:
  • More or less shoot like you would regularly; shorter exposures; less noise; potentially no need for tripod so handheld shots possible
  • Generally much better image quality than using unmodified cameras with IR filters
Indeed only two bullet points, but that first one is packed full of positive goodness. Now depending on the direction you take with the modification, professional or do-it-yourself, some cons do appear. Professional modification may be pricey and if you're the tinkering type but manage to put a thumb print on the sensor, then you're not only out of a camera, but a few bucks too as you'll likely replace it.

But let's move on to taking shots using an IR filter. As you saw in the video, although I collected my thoughts before shooting the segment by the lake, it was still unscripted and a tad rocky. Nonetheless, I roughly covered the steps and to fulfill my in-video promise, here is the general procedure I followed to take my IR shots:
  1. Without the filter, I composed the shot I wanted to take
  2. I prefer using manual focus, but really you could use auto-focus and then lock it by switching to manual once the camera finishes its task (i.e. set camera to auto-focus, then press shutter button half-way, then switch to manual focus mode but don't touch the lens focus ring)
  3. I always took three exposures with the following settings: f/4, shutter speeds of 1, 2, and 3 seconds, with sensitivity at ISO 200. Now I was bathed in bright sunlight, but depending on your shooting conditions, these settings may not do much good, so you will have to experiment a little. Here's a quick tip too if you're finding that your focus is off: simply use a smaller aperture, like f/8 or f11; keep in mind though, with a smaller aperture comes longer exposure times.
  4. Now place the filter on your lens
  5. Shoot away!
One thing I was reminded of during my on-location shoot was how difficult it can be to see the LCD screen in daylight, so taking several shots at multiple exposures almost guarantees you'll have at least one workable photo, even if you can't quite tell which shot works and which doesn't. And I'd like to add something that may aid in viewing IR photos on your camera after you take a shot or two. Perhaps try to set the white balance to as low as it will go (e.g. 2,000K), and see if that neutralizes the red tone a little. I wish this occurred to me sooner, as I would've tried it and suggested it in the video if it worked; for another day then!

I'm just starting to realize the sheer size of this post! Ok, to finalize things, my second video encompasses a quick Photoshop tutorial on how you can post-process IR photos. Indeed, shots out of he camera are very red in tone, which should be no surprise as the IR filter essentially only allows very deep reds and near IR wavelengths of light through (although there is a tad bit of color data there). The first segment in the video demonstrates false color processing and the second part shows how to process IR photos into black and white (or grayscale). In a nutshell, there are many different ways of processing these pics, so I suggest you examine some of the links below in the resources section to see what else photographers are doing. I would personally say that there is hardly a "right" or "wrong" here too. Instead, this is a matter of taste where some people love the false colored versions of the photos with those dark blue skies and pinkish (near white) foliage, or hate it and like the black and white style.

So for the next episode, I'll be showcasing high dynamic range imaging (HDRI or HDR photography). It seems to be a popular topic as I've already had two requests for it! Awesome! So have fun with the IR stuff and TTYL! L8r!

Web Resources
http://en.wikipedia.org/wiki/Infrared_photography
http://www.wrotniak.net/photo/infrared/
http://www.hoyaoptics.com/color_filter/ir_transmitting.htm
http://www.hoyaoptics.com/pdf/R72.pdf
http://en.wikipedia.org/wiki/Infrared
http://www.absoluteastronomy.com/topics/Infrared_vision
http://www.luminous-landscape.com/reviews/cameras/infrared%20dslr.shtml
http://www.microscopy-uk.org.uk/mag//artmay10/dw-s75-ir.html
http://www.dpfwiw.com/ir.htm
http://www.shotaddict.com/tips/article_How+To+Post+Process+Your+Infrared+Digital+Photos.html
http://tutorials20.com/misc/infrared-photography/
http://khromagery.com.au/ir_raw.html
http://www.smashingmagazine.com/2009/01/11/40-incredible-near-infrared-photos/
http://www.webdesignerdepot.com/2009/06/100-outstanding-and-inspirational-infrared-photos/

Saturday, June 26, 2010

Infrared Photography, Part 2 - Photography with Imre - Episode 24

Hey look! It's almost midnight! I think I'm starting to be very predictable with these uploads. Anywho, part 2 of infrared photography is live on YouTube. Overall I like the way this episode turned out. I used to teach Photoshop some years ago, so this wasn't all that different; very specific perhaps and limited in time as I have to keep the videos to under ten minutes in length (maybe someday I'll become a YouTube partner and I can break that barrier... then no one will watch my epic nine hour long Photoshop tutorials! On second though, I'll keep'em shorter).

As for the supplemental blog post, I will be combining both parts one and two as they relate to each other very nicely indeed. Hopefully in a few days I'll have that written up and I do have several IR links to add... well the links aren't in infrared, you'll be able to see those. *chuckle* Oh dear. It's very late.

Monday, June 21, 2010

Infrared Photography, Part 1 - Photography with Imre - Episode 23

Well I just uploaded episode 23 of my photography series on infrared photography; this show being a response to a request (off a profile comment). No big surprise here, it's once again getting late and I need a little shut-eye. So enjoy the video and I will of course be working on a supplemental blog post in the next few days... or so. L8r!

Saturday, June 19, 2010

Part 2: Lightning Photography - Photography with Imre - Episode 22

Well it's about time I finally wrote the supplemental post to my lightning photography video! Home renovations have taken away quite a lot of my time, although I must say that I'm quite impressed with the paint work I've done! I'm generally more used to sitting by my computer most of the day programming or working on videos, writing, etc., not doing physical work... and I swear I've lost some weight!

Anyway, enough about home renos, let's talk about lightning! Before moving on, I can't stress enough how dangerous it can be. During my research on the topic of lightning and storm safety, I was a bit surprised to discover that lightning kills more people per year on average in the U.S. than hurricanes and tornadoes! Indeed, like NOAA's article expressed, the damage caused by other weather phenomenon are more visual and widespread, whereas lightning takes a more targeted approach, if you will, and hence it's not noticed as readily. So if you're one to venture out and do this kind of photography, and to make the legal folks happy, educate yourself well, be very careful, and you're doing so at your own risk!

In regard to the video, I'm quite happy with the information presented, but I almost forgot to mention the use of a tripod when using long exposures (luckily I added it as a bullet point). Unless you have some stunning super-human ability to hold completely still, blurry photos will be the result of hand holding a camera and using a multi-second long exposure. And by chance if you don't have a tripod, then your best bet to stabilize the shots will be to brace yourself against something, or perhaps put the camera down on a solid surface; angling the camera using the latter method would be a bit of a challenge though.

I also talked about finding a location that is not only safe, but provides a composition that results in a photo worthy of display in an art gallery. But, this may or may not be your goal. Many photographers simply like to capture a nice bolt, and frankly I've been there too... especially since I've never really bothered to drive out to a location where I could take some of those amazing shots; well there is that one time with the supercell that just missed Calgary, which you saw in the video. The thing is though, we may not always be able to get to such a location because of our busy lives, or time of the storm, or whatever other circumstance stands in our way. But as I was perusing through Flickr, I came upon some awesome and inspirational shots, where even though the storm appears to be right overhead, the rest of the locale beautifully compliments the electrical action. So as you'll see, assuming you like these photos as well, a storm doesn't necessarily have to be in the distance (it's just generally safer unless you have a cozy Faraday cage):

http://www.flickr.com/photos/wvs/3806517643/sizes/l/
http://www.flickr.com/photos/27091991@N06/2528583346/
http://www.flickr.com/photos/frankba/3729668561/sizes/o/
http://www.flickr.com/photos/ozlandscapes/3083269329/sizes/o/
http://www.flickr.com/photos/digiquest/205517510/

Lastly, I'd like to quickly discuss the implications of noise when long exposures are used (digital camera of course, not film). Generally, I turn noise reduction off when taking shots of lightning. At ISO 100, even my aging E-3 produces a very clean image. When I first got the camera, I took some star trail shots with the shutter open for a full minute. Other than a few hot pixels here and there, the image was quite good; keeping in mind, lowest ISO setting. However, if I were to turn on noise reduction, the camera will take another exposure of equal length to the exposure used to take the picture with, but his time with the shutter closed. This allows the camera's brain to perform what is called dark frame subtraction, which helps cancel out some of the noise generated by the sensor.

So I may get a very slightly improved image in terms of quality, but I'd have to wait for another exposure cycle before I could take the next shot. In other words, if I'm keeping the shutter open for 15 seconds, then I'd have to wait for another 15 seconds after the actual exposure is done (total of 30 seconds), before I could press the shutter button again. But the problem is that I could lose a nice lightning bolt or two during that second exposure. Actually, here's a good place where you might consider shooting RAW if you don't already, as the extra editing room RAW provides might allow you to reduce some of that noise in your favorite editing program (e.g. Photoshop).

Well midnight is creeping up on me, so I suppose I should trudge over to my bed and dream up some electric sheep. And in the coming days I'll be doing my best to complete my next video, so as usual stay tuned for that and I'll be posting updates on Facebook and Twitter. L8r!

Web Resources

http://www.lightningsafety.noaa.gov/overview.htm
http://news.nationalgeographic.com/news/2004/06/0623_040623_lightningfacts.html
http://van.physics.illinois.edu/qa/listing.php?id=533
And do a search on Flickr for lightning; there are some amazing shots from great photographers there!

Wednesday, June 9, 2010

Lightning Photography - Photography with Imre - Episode 22

I had a lot of fun creating this episode on how to photograph lightning, and I have quite a bit more to say in my supplemental post, which as usual I will write up another day. Once again it's a tad late... and strangely, I am really craving cereal right now. So off I go to eat and I hope that you enjoy this episode!

Oh! And before I run off, thank you to the viewers who sent in some great topic requests, which I'll be working on for future episodes; namely High Dynamic Range (HDR) photography and infrared photography. Tres cool!

L8r!