The X Factor

The following article was written for my Web site about 2 years ago. I am moving the articles on my Web site over to my blog so here is the first one.

Enjoy

The X Factor

Lens conversion factor came into play early in the digital imaging revolution. It was developed as a way for 35mm shooters to know how the perspective of their lens would look on a digital camera. To get an idea of how it works, imagine a 4x6 print. Now draw a box on the picture about 2cm in from the edges. The 4x6 print represents the full size sensor(or 35mm film) while the box inside represents the sensor in your camera, (or any other digital camera). Keep in mind that this is only a representation and not dimensionally accurate. If you were to enlarge the part of the picture inside the box that you drew to a 4x6 print, it would appear as though it was taken will a longer lens. The X factor is a ratio of the sensor size relative to the full size sensor (or 35mm film). There are many different size sensors out there so the x factor be different depending on the cameras that you are using.

On a digital SLR like the Canon Rebel XTi, the X factor is 1.6. I usually use 1.5 because the math is doable in my head and the difference is not significant. Therefore, a 50mm lens will give you the same perspective a 75mm lens on a 35mm camera (50 x 1.5 = 75), a 100mm lens will give you the same perspective as a 150mm lens on a 35mm (100 x 1.5 = 150), and so on. So, the X factor is really just a conversion to give lens magnification on a DSLR relative to a film SLR or Full Size sensor DSLR.
Interesting to note that photographers had this similar issue before digital as well. There are many other film formats out there besides 35 mm and each one requires different focal length lenses to achieve the same effect.

The zoom factor is a ratio of the longest focal length of a lens divided by the shortest focal length of a lens. It is not particularly relevant for a DSLR because the lenses are interchangeable and the zoom factor will be different depending upon the lens.

So lets do some calculations. The zoom factor for a 18mm - 55mm lens is 55mm/18mm=3 or 3x optical zoom. Calling it optical zoom is somewhat redundant because we are talking about a lens which is only optical but eh. The zoom factor for a 50mm - 200mm lens is 200/50= 4 or 4x optical zoom. The zoom factor for a 75mm - 300mm lens is 300/75=4x or 4x optical zoom. And on it goes. You can use the X factor to recalculate the relative focal lengths but it won't change the answer so why make life more confusing.
In the world of fixed lens cameras and point and shoot cameras this is great to know because you can get an intuitive idea of how a camera will respond. For example; a canon SD1000 has a 3x optical zoom with its widest angle being 38mm equivalent. Using the zoom factor ratio we can determine that when it is fully zoomed out it will have the equivalent of 38mm x 3 = 114mm lens on a 35mm camera. On a super zoom such as the Olympus 550UZ, the zoom is 18x and starts at a 35mm equivalent of 28mm. Therefore when zoomed fully out it will have a 35mm equivalent of 28mm x 18 = 504mm.

With a DSLR, the lens is interchangeable, and each lens will have its own zoom factor as shown earlier in some of the calculations. What happens when you have more than one lens in you camera kit? Do you have different lens with different focal ranges and different zoom factors or do you a series of lens that will take you through an expanded zoom range and a zoom factor that encompasses you entire kit? There is no definitive answer to this but I prefer to view my camera as a system and therefore would look at it as a zoom factor that encompasses the entire range of my lens. Using this logic then, lets recalculate the zoom factor for a DSLR kit.

Lets assume that you have an 18 - 55mm lens that comes with the camera. Then, as calculated above, you have a lens with a 3x optical zoom starting at 18mm. Now assume that you decide to purchase a 55 - 200mm lens. As calculated earlier, this lens is a 4x optical

zoom. But in your kit you now have lens ranging from 18 mm to 200mm, so effectively, you have the capability of 200mm/18mm=11 or 11x optical zoom starting at 27mm equivalent (18mmx1.5=27mm). Interesting huh?

Return from Hungary

I have been back from Hungary for over a week now and I am still sifting through images. Wow, what a great trip and such a wonderful place to visit. The photographic opportunities are amazing and the people are very warm and welcoming.

Gellert Hotel, Main Entrance
Canon 6D, 24-105@24mm, 1/20@f4, ISO 1600

The trip was built around a photographic master class led by David Ziser and Clay Blackmore. Two photographers that I have wanted to study with for years. It was fantastic to finally be able to spend some time with these guys and get to know them. There were about 14 other students in the class (I never stopped to actually count them). We were together for seven days, studying and photographing for about 12 hours each day. It was exhausting but well worth it.

This is the Gellert hotel where we called home for the duration of the trip. It is built in 1916 and contains the world famous Gellert Spa. The building is filled with history, being the home away from home for the leaders of the German army during WWII and then by the Soviet Union. The spa area was, during the Soviet occupation a public swimming pool for the people of Budapest however the hotel itself was off limits. As the story goes, only tourists and Russians were allowed in the hotel area.

The building itself is an incredible piece of architecture and the public areas a well maintained and have kept the original feel of the building. The rooms are comfortable but show signs of long term neglect and patch it so it works and that's good enough repairs. I suspect there are plans in place to bring the hotel back to its original glory. I very much enjoyed my stay there.

The indoor pool at the Gellert Spa.
Canon 6D, 24-205 @24mm,1/30 @ f4.0, ISO 2000

Originally, Budapest was two cities - Buda and Pest. When the Freedom bridge was built, the two cities were joined together and became Budapest, and the capital of Hungary. This image of the Freedom Bridge as it crosses over the Danube from the Pest side to the Buda side. At the Buda end of the bridge is, of course, the Gellert hotel. There were seven bridges that cross the Danube, all of which were bombed out during WWII. All the bridges were rebuilt to resemble there original forms except one, The Elizabeth Bridge, which was built between 1960 and 1964, nearly two decades after the destruction of the original bridge was destroyed and used cable suspension designs of the day. An 8th bridge, The Megyeri Bridge, was constructed between 2006 and 2008 and is a modern looking cable construction bridge.

The Freedom Bridge leading to the Gellert Hotel
Canon 6D, 25-105@45mm, 2.5 sec @f5.6, ISO 160

The Freedom Bridge
Canon 6D, 24-105 @ 55mm, 1400@ f5.6, ISO 160

The Chain Bridge
HDR Composite

That's it for today. More images from Budapest next post.

Len

Lake time

It's lake time once again, and the first thing that gets packed into the truck is the camera gear. It's a force of habit I know, but I don't think I have ever gone to the cabin, our any place else, without it. It's a part of me and in many ways it is who I am. It's been this way for years now and it is likely to never change.

I always enjoy going to the cabin and one of my favourite things about it is that there is always something to tinker with. Something always needs fixing. This trip had a couple of minor issues, the door on the dishwasher was out of kilter and some general clean up of the property, but there was one larger issue to take care of. The effluent pump was not working!

When we arrived, my brother in law had already determined that the problem was not actually the pump but a problem with the power supply. We opened up the electrical box and discovered a corroded mess. All the wires had corroded to the point where the wire needed to be replaced all the way from the box in the cabin out to the sump area where the pump is.

As is the case at the lake, a major problem such as this requires a beer and consultations with the rest of the cabin community. As we were approaching the need for a second beer, our close friend Kent say "hang on, I think I get some BX cable at the cabin". 10 minutes later he's back with his son in law who happens to be an electrician, and guess what, he's got his tools with him and all the parts we need to do the job. An hour later, the pump is back in business and everyone is one again able to do their business.

Our electrician friend was a true professional. In his mind, there was no question that he would have his tools with him. They are what he does and they are a part of him. He also wanted to help. You could see that being able to use his craft gave him joy. What a wonderful gift.

As photographers, we need to see our cameras in the same light. They are the tools that we use to do our craft. I could not come up to the cabin and be comfortable without my camera. The interesting thing is that every time I come up, I have occasion to use it. And every time I come home with some different images.

Focal Point

I believe that education in photography is essential if we want to keep up with the ever changing technology and still maintain photography as a viable art form. Today there are many non traditional ways to learn about photography, particularly on line. A quick search on the internet will show literally millions of sites that are dedicated to teaching you how to photograph. Some of them, like the New York Institute of Photography, can prove to be a viable way to learn photography as an art. However, most of them fall well short.

The best way to get a photography education is to work with a instructor in a structured program that has well defined learning outcomes so that at the end of the process you walk away with a well rounded foundation in photography. Places that do this well are hard to find. 

Focal Point Visual Arts Centre has been providing this level of quality education in Vancouver for 39 years. This month, we will be loosing Focal Point. As an alumnae of Focal Point as well as one of its instructors, I know that it will be missed.

I want to take this opportunity to thank Focal Point for being a big part of my photography career and to wish all the best to my students and the staff.

Mid August Already

Wow, I can't believe that we are already in the middle of August. It's been a busy summer filled with weddings, portraits, and teaching. Starting to prepare for the fall season now. Here's what's happening.

Now is the time that I start photographing students who are graduating in 2013. I know it seems a bit early, but it is the best time. This way we can still catch the nice weather of summer or the fall colours in about 6 weeks. If you know anyone who is graduating in 2013, get them to call me now. Last year there were many who left it too late.

Wedding season is in full swing right now.It's been a great season and it has been a lot of fun. Mid September is when the wedding shooting will start dying down and the album production will be in full force. This is also the time when I start putting together next years promotional wedding materials. I looking forward to presenting some exciting new offerings including an album on an iPad.

There is 4 weeks left in the wedding photography class that I am teaching at Focal Point. The students have been doing some excellent work. The fall semester starts in September and I will be teaching wedding photography, flash photography, Commercial Portraiture, and practical studio lighting. The fall course schedule will be posted soon on the Focal Point web site. These course fill up fast so sign up early.

That's it for todays update.

Idea books

Next week starts my next group of flash photography students and one of the things that I tell all my students is that they need to create an idea book.  In a nutshell, an idea book is a collection of your own images that you have put together along with information on how you photographed them. It is one of the best long term learning aides that I have ever discovered.

The concept of the idea book is to create a collection of your own images that you can use to spark your creativity and as a source of images that you can build and improve upon.  So how does this idea book work?

Building and idea book.

1. Find yourself an album that can hold 4x6 prints.  The large the album, the better.
2. Get a bunch of 4x6 index cards

When you take an image that you like, make a 4x6 print of it and put it in the album.  Write down every detail of how you photographed the image; lighting, exposure, location, time of day etc.  Even if the image isn't perfect, but you like the concept, put it in the book. As you get more and more images in the book, you will be building a source of ideas that can trigger your memory.  It will also help you become a better photographer because you can go back to an image you like and work on it and make it better.

Its awesome.  Many photographers on the lecture circuit sell there idea books.  If you want, you can pick one or two of these up as starting points, but ultimately you need to be the one taking the images or you will never understand how they were created.

Camera Clubs

Looking for a fun way to improve your photography.  Check out your local camera club.  I recently joined the North Shore Photographic Society here in North Vancouver and am enjoying my experience very much.

One of the challenges to improving your photography is knowing if what you are doing is working.  Asking friends and family their opinion on you images is a start but very often they won't tell you the whole truth.  They are your friends after all, and they don't want to hurt your feelings.  It is also likely that they are not artists or photographers, so they are unsure what to tell you.

A camera club is a group of like minded people who want to practice and share their photography.  As such, they are a great source of subjective feedback - especially the folks who have been there for a while. Clubs will have monthly slide and print critiques, making feedback is a huge component of what they do.

Another fun aspect of a camera club is that they arrange field trips and guest speakers to come in and share their knowledge or special technique.  So, you get a chance to photograph things that you may not otherwise get a chance to photograph and hear about different ideas, all on a regular basis.

Camera clubs can not replace professional photography organizations, and I will always recommend that you belong to them.  Nor will they replace professional print competitions. But I do recommend them non the less.

Photolen

First Snow Fall

After completing a series of Corporate head shots, I left the building and was presented with this beautiful scene.  It was the first snowfall here in Vancouver and I could not resist taking this image.

Camera 7D, Lens 70 - 200mm F2.8 at 95mm  iso 800

where did the time go

I can't believe how long it has been since my last post.  After my last post I had to head out of town to photograph a wedding  I was gone for a week and when I got back the plane did not even get a chance to touch down before I was running around.  Being busy is great, unfortunately my blog suffered. 

Next week I start teaching my courses at Focal Point.  I will be doing one course on commercial portraiture and another on wedding photography.  There is a lot of prep involved but it's going to be a lot of fun.  Hope some of you can attend.

As for my series on composition.  Sorry for the delay on the next posting but it will be coming soon.