Friday, May 28, 2010

Part 2: Aperture Revisited - Photography with Imre - Episode 21

Now that's the way the episode on aperture should have been done the first time! I'm definitely happy with this show; properly scripted and plenty of diagrams and graphics to clearly illustrate the topic. Plus, I included a much better and detailed explanation of it too!

As usual, there are some links below if you'd like to find out a little more about the topic. Some of these sites (even Wiki, although I'm not a huge fan of it as more or less anyone can edit the articles) go into a fair bit of detail, but that of course that doesn't mean you need to know everything about f-numbers and entrance pupils to be a good photographer. As long as you have a strong grasp of the fundamentals, you'll be able to relate and manipulate settings with ease and most importantly, come away with the results you expected. And speaking of relating...

I did want to give a few more examples of how aperture, shutter speed, and sensitivity (ISO) interact. Below are some exposure settings that should result in virtually identical photos, except for depth of field which will change as the aperture size is manipulated:

1. Aperture: f/5.6  Shutter Speed: 1/15  ISO 200
2. Aperture: f/2.8  Shutter Speed: 1/60  ISO 200
3. Aperture: f/4     Shutter Speed: 1/15  ISO 100

I'll compare the second example to the first and third to the first as well to keep things simple. In the second example, the aperture size has been opened two full stops (from f/5.6 to f/4 to f/2.8), which means that four times as much light makes it through the lens (remember, if you open up one stop, twice as much light can get through). But to get the same result when taking the photo, the shutter speed is four times as fast; from 1/15th of a second to 1/60th of a second. Therefore, although four times as much light gets through to the sensor, the is only open for a quarter of the time.

As for the third example compared to the first, the aperture has been opened up one full stop, thus letting twice as much light through the lens. But you'll notice that the sensitivity of the sensor has been reduced to 100, which means that the sensor is now half as sensitive to light. And there you have it.

The last thing I'll quickly mention is in regard to depth of field. Although the size of the aperture affects how much of the photo will be in focus, distance to the subject (really to the point you're focusing) will also change the depth of field. As you may have already noticed, if you shoot a tiny little  insect with a macro lens set to f/4 let's say, only a millimeter or so of the picture is sharp. But point that same lens using the same f-stop at a mountain a kilometer away, and you'll likely see that pretty much everything is in focus!

So off I run for now! For the next episode, I'll be showing a neat trick shot that relates to aperture, so stay tuned for that! Also feel free to send me suggestions or questions for future episodes, and you never know, I just might honor your request! L8r!

Web Resources

http://en.wikipedia.org/wiki/F-number
http://en.wikipedia.org/wiki/Aperture
http://en.wikipedia.org/wiki/Entrance_pupil
http://www.dpreview.com/learn/?/Glossary/Exposure/Aperture_01.htm
http://digital-photography-school.com/aperture
http://www.photoxels.com/tutorial_aperture.html
http://www.cambridgeincolour.com/tutorials/camera-lenses.htm
http://blog.epicedits.com/2007/06/16/so-you-think-you-know-what-an-f-number-is/

Monday, May 24, 2010

Aperture Revisited - Photography with Imre - Episode 21

Hoot and holla! I finally finished Aperture Revisited! I am pooped as I've been working all day long on this video, along with having to fix the black hole shielding on my space craft. You can get a glimpse of it, in addition to some bloopers, in the video. As for the actual supplemental post, I should have that finished in a few days, so do keep checking back. L8r!


Monday, May 17, 2010

2.1GB Hard Drive for How Much? Little robots in TVs?

Here's an interesting relic from the mid 90's... 1996 if my memory serves me right. I decommissioned an ancient computer system I began using as a dust collection apparatus many years ago, which will soon be happily recycled into whatever old computer systems are recycled into, and still adhered to the hard drive was this sticker (see image below). Yes, you see that right. It's the price tag for an incredibly spacious and very speedy 2.1GB Ultra-Wide SCSI hard drive. Back then, the drive this sticker belonged to was state of the art. And who could really argue with that price? $1,430? Sold! I don't think I've seen hard drives this expensive these days, excluding some of'em fancy solid states ones.

And in case you're wondering what I was doing with such a super-duper crazy fast drive, the answer is video and 3D animation. Back in the good old days, when the World Wide Web had 12 sites, three with photos and not just text, you had little choice but to get one of these drives to capture video with, as well as play it back, without dropping frames when outputting to your video recording device. In my case, for work I did, I rented a Betacam SP deck and for my own purposes (i.e. demo reel) I utilized a machine called the VCR, which employed the use of VHS tapes. Unlike motion picture film on which you could see the captured images, VHS was a magical medium. If you examine the strange, dark, thin, and very flexible material, no images can be seen. But put one of these tapes into the VCR and the little but fast robots (made in Japan) could "see" those pictures and quickly tell their brethren in the television set (through wires!) to paint the images on their giant window glass. Of course for us humans this glass is what we watched the shows on (like Alf, Knight Rider, and Airwolf). The vacuum inside the television set tube is what allows these micro-robots to move about at their extreme speeds; no friction from the air. ... Oh my! I'm rambling on, aren't I. I always enjoy a good walk down memory lane. Well, enjoy the sticker-shock!


P.S. MacGyver's first name was Angus!

Friday, May 14, 2010

Part 2: Zoom Trick Shot - Photography with Imre - Episode 20

Before I get into the supplemental post, I just want to say that I've been getting some great feedback for Episode 20 and I'm always happy to get comments - thank you all!

Now something I did not mention in the video relates to where this effect is and could be used. Funny thing is as I was running through my video before uploading it, my father walked in the room with a pamphlet. He opened up the leaflet and to my surprise there was a photo of a couple of people riding on a motor-scooter, with a similar zoom effect I showed off in the video. Neato! Indeed this effect is not one that I believe would work in many places, but it's a clever way to illustrate or add movement to a photograph, as well as to convey mood in some cases. Aside from two wheeled vehicles, I've also seen such shots with cars and aircraft, along with zoomed shots through sunlit forests. Flickr is a great site to conduct some searches to see what photographers are coming up with.

Another point I'd like to add is that if you're using a tripod for these type of shots, then you most certainly could use long exposures (e.g. several seconds or even minutes). In fact, click here for an example of such a photo. A solid tripod and steady hands could yield some very interesting outcomes. Imagine what a lengthy exposure of stars would look like while slowly zooming in or out. Without a tripod though, your images would turn out like some of mind did as I was out in my backyard snapping away taking shots for the episode - blurry. Simply said, we humans are just too wobbly.

Lastly, my father had a really neat idea for a motioned zoom shot, and by that I mean a photo where you not only zoom, but also pan in a direction (like that pine tree photo in the video; also displayed below). My dad's idea was to rotate the camera around the optical axis of the lens while zooming. I love the idea, which would create an effect mimicking the radial blur filter in Photoshop, but we contemplated that it might be a bit difficult to produce. My dad mentioned rotating the camera, which might work if you had a lens with it's own mount. Then you could attach that mount onto a tripod (versus the camera to the tripod), and if the ring around the lens could be loosened enough to allow free rotation, then the trick might just work... I'll have to try that out someday soon!

To close off this post, here are some of the shots taken for the making of this episode, with links to their respective homes on Flickr where you can see them at a larger size. If you haven't already, please subscribe to my humble YouTube channel, and there are links to the side pointing to my pages on Facebook and Twitter. L8r!




This is the tree photo taken while both panning and zooming.




Thursday, May 13, 2010

Zoom Trick Shot - Photography with Imre - Episode 20

Late night has crept upon me again, but that didn't stop me from uploading the 20th episode in my photography series! I'm still working out the details on the aperture remake, but bare with and eventually you shall see that one appear from the mist. Anyway... hope you enjoy this quick trick shot video and the official supplemental post will come tomorrow. L8r!


Monday, May 3, 2010

Part 2: RAW vs. JPEG Part 2 - Photography with Imre - Episode 19

Well I think it's about time that I finished writing the supplemental post to RAW vs. JPEG Part 2!

First up, during the JPEG cons segment I talked about how there is no going back to an original image state per se. In a way this is only partially true. As long as you keep a copy of the original JPEG file that came out of the camera, then you can always open it up time and time again and save it as a different file (e.g. Photoshop format) to edit it further; so you can in fact return to an "original image state" if need be. But, if you save the original JPEG file over and over again under the same filename, keep in mind that the quality will degrade; in a remote way, this is somewhat similar to making a copy of a copy, then a copy of that copy, etc. Each time you save the file, it is compressed again and again, and each time a little bit more of the image quality is lost (in all fairness though, there is a lossless JPEG type).

On the other hand, working with a RAW file is safer. For example, if I open up one of my Olympus RAW Files (.ORF) and hit save, then Photoshop displays a dialog box asking me to save the file in one of several image formats. So at the least, I cannot accidentally overwrite the original file. Now going back a bit to the "original image state" I talked about, remember too that the RAW file format isn't processed. Therefore, it preserves the camera's sensor data essentially perfectly, unlike the JPEG files the brains of the camera massages and manipulates to a state where you cannot rewind time to get at that precious primeval sensor data.

Next, I said in my video that I would write a little bit about dynamic range. Dynamic range is quite the topic of it's own, so I've included a couple of great links below which do a fantastic job of explaining it better than I could. Feel free to check'em out.

And lastly... I'm finding it somewhat challenging to add more to the second-half of my video where I discuss which format to use. Frankly, my hope is that whoever comes across my video or this post examines his/her situation and the pros and cons to both RAW and JPEG, so s/he can make his/her own decision about it. Plus, aren't digital cameras just awesome. I mean, unlike the good old days of film where you were stuck with a specific speed and type of film until you shot each exposure (or extracted the film before it was completed used up), with digital we can happily switch the sensitivity on the fly, shoot in black and white or vivid color, and even easily switch between saving our moments in RAW or JPEG format (or both!), all without having to change the fi... memory card. Brilliant! Isn't it?

Web Resources
http://www.cambridgeincolour.com/tutorials/dynamic-range.htm
http://www.dpreview.com/learn/?/key=Dynamic_Range