This is a quick review on the Interfit EX150 MKII 3 Head Lighting Kit that includes the following items:

EX150 MKII heads x3 (three included)

100 watt Bulbs x 3

Lighting stands x3 (2 tall, 1 compact)

60cm (24″) Softbox x1

Translucent Umbrella  x1

Educational DVD

Sync and power leads x3

9ft x 30ft (2.4 x 6m )Background cloth x1

Snoot x1

All in one Kit Bag  

More information can be seen at the Interfit website at http://www.interfitphotographic.com/index.htm .

First, I should say that I am by no means a portrait photographer!  I normally loathe taking photos indoors where I have to play around with white balance adjustment, mounted flash units, etc.  As you may have seen from my other galleries, I am much more at home with allowing mother nature to illuminate my subjects, which consist predominately of wildlife.  So you can imagine my initial reaction when my wife approached me about doing some professional photos for her practice’s website. 

I had two options.  First, I could have told her to get them “professionally” done and in the process spend several hundred dollars for a photoshoot that would potentially result in limited access to the final photos or require us to buy the rights for use on her website.  The second option was to use that same amount of money (around $550 total US dollars) to invest in a lighting kit that would allow (or force) me to branch out into portrait photography.  Obviously, since I am doing this review I decided on the latter and am glad I did. 

But I am now getting ahead of myself…  First, I started by visiting my favorite local photography store, The Houston Camera Exchange ( http://www.hcehouston.com/ ), as I knew they would have many options for studio-type lighting and plenty of informed salespersons to help answer my questions.  After only a few minutes of browsing the store, I quickly realized that this venture could be a very expensive undertaking.   I mean I was looking through various lighting heads, light stands, backdrops, softboxes, umbrellas, and snoots.  And if you are anything like I was at that time, I was asking myself what the hell is a “snoot”.   I will digress for a moment to define a “snoot [as] a tube or similar object that fits over a studio light or portable flas and allows the photographer to control the direction and radius of the light beam”, per wikipedia.   Anyway back to the story, luckily for me, a nice sales associate must have noticed my stressed look and came over to help.  I explained my situation as a predominately nature photographer who would like to spend as little money as possible for a decent quality lighting system.  I told her the lighting system would likely only be used occassionally for family portraits and professional photos.  She smiled and said she had just the thing, as she led me to a shelf with the Interfit Lighting Kits.  After a brief description of the contents of the Interfit EX150 MKII 3 Head Lighting Kit, I was sold!  Basically, this kit has everything  that one would want to start taking professional-looking studio portrait photos, with the exception of a light monitor and stand for the background cloth.   The Houston Camera Exchange was having a promotional deal that included a second softbox for free with the purchase of the kit, thus giving me two soft boxes and an umbrella.   I decided to purchase a seperate interfit backdrop cloth support rack from B&H for about $50.  Though I bought my Interfit EX150 MKII 3 Head Lighting Kit from a local store, the same kit sells at B&H for $399 plus shipping and does not include a free 2nd soft box. 

I will be the first to admit that I am not one to read directions.  I ended up watching the education DVD that is included with the kit and some other instruction demos on youtube.  After this initial ”research” I assembled the lighting system and “played around” with it for about 30 minutes before inviting my wife to join for the photoshoot.  After an additional 30 minutes of  a trial-and-error photoshoot ,  I had some photos that we were both very pleased with.    I would never claim that they are the best portait photos ever, but they are also not too bad for a first attempt and only 30 minutes practice.  I guess the main point I am trying to make is that Interfit EX150 MKII 3 Head Lighting Kit  is very easy to use and get quality results with, even by a novice like me.   I highly recommend the Interfit EX150 MKII 3 Head Lighting Kit for anyone looking to get professional quality studio protraits for an inexpensive price!

Additional items recommended:  A light meter would be really helpful and is something I will invest in sometime soon.  You can certainly get the correct exposure and lighting strength without one, but it would have made the process even faster.   Backdrop cloth rack that I purchased sepertate is helpful and allows me to set the background cloth up anywhere.  The kit does come with a set of plastic hooks that you can attach to a wall via those removeable adhesive strips.  That would probably work fine if you have one wall of you home/studio that you will always does your portrait work, but an actual seperate support rack makes it quite mobile.

SAMPLE OF FINAL SHOTS:

Here are some of my wife’s favorites that she is deciding between for the website, though there were 14 photos that made her final cut.  

My wife and I came upon tickets to the last game of the 2011 Baseball regular game between the Houston Astros and St. Louis Cardinals.  Though, I am from Houston, I was hoping to see the Cardinals win since a Wild Card Playoff position was at stake for them.  Anyway, I digress but this was my first chance to take my Nikon 70-200mm f2.8 VRII lens to a professional sporting event.  I also brought my Nikon TC-20EIII teleconverter to see how it might perform when paired with the 70-200mm f2.8 at such an event.

First, I would highly recommend that you check with any ballpark or stadium that you plan to bring any lens “larger” lens.  Personally, I assumed that the 70-200mm f2.8 was not large enough to even attract attention by the “bag checkers” at the gates, but I was wrong.  The lady at the bag inspection table actually said she would need to ask her supervisor if the lens was too big to all in the stadium.  He said it was fine to allow in, but the fact that it was even in question makes me want to give this advice.

Overall, I was very pleased with the performance of the Nikon 70-200mm f2.8 VRII both alone and with the Nikon TC-20EIII teleconverter…at least for my purposes.  Obviously, the teleconverter limited the acceptable shots to predominately stationary photos of players, but I also got several good action photos despite a slower shutter speed to compensate for the increased f-stop.  You could probably get away with even a faster shutter speed with a FX camera that would allow for higher ISO. 

Shooting conditions:  Indoor stadium/baseball park with roof closed and stadium lights on

(BELOW) Nikon 70-200mm f2.8 VRII at 240mm, f5.6, 1/125 sec and ISO 400

(BELOW) Nikon 70-200mm f2.8 VRII at 200mm, f2.8, 1/200 sec and ISO 400

(BELOW) Nikon 70-200mm f2.8 VRII at 195mm, f2.8, 1/200 sec and ISO 400

(BELOW) Nikon 70-200mm f2.8 VRII at 200mm, f2.8, 1/200sec, and ISO 400

(BELOW) Nikon 70-200mm f2.8 VRII at 190mm, f2.8, 1/250 sec and ISO 400

(BELOW) Nikon 70-200mm f2.8 VRII with TC-20EIII teleconverter at 400mm, f5.6, 1/125 sec and ISO 400

(BELOW) Nikon 70-200mm f2.8 VRII with TC-20EIII teleconverter at 400mm,f5.6, 1/125 sec and ISO 400

(BELOW) Nikon 70-200mm f2.8 VRII with TC-20EIII teleconverter at 400mm, f5.6, 1/125 sec and ISO 400

Feel free to leave comments or your experiences…

-Kyle

http://ksqphotography.wordpress.com/

http://ksqphotography.zenfolio.com/

I visited Jackson, Wyoming in August 2010 and had the pleasure of touring around the Grand Teton National Park area and the southern loop of Yellowstone National Park.  I had plenty of time to explore and feel like I found many of the top scenic and nature sites in the area.  I put together this pdf file which contains an annotated map of Yellowstone’s southern loop with some of my favorite photos fromeach location.  Each site is designated with a yellow star that you can click on to provide a brief description of the site.  There is also reference to a “Slide #”, of which the slides can be found below the map and possess a few sample photos that I took from each area.  Obviously, there is nothing quite like experiencing a destination for yourself.  But, I hope this resource serves as a mini tour guide to help you prioritize your photography trip to the Yellowstone.  

Click below for the pdf file or right click to download (WARNING, this is a huge file (15MB) due to the size of the map and photos.  It may be easier to download this file for viewing versus doing so in your internet browser window.  Also you will need adobe acrobat reader to view the pdf file): 

Yellowstone National Park Southern Loop Map and Photography Tour

See also a similar map for Grand Teton’s National Park (below):

Grand Teton National Park Map and Photography Tour

I would be happy to answer any questions you might have.  Enjoy!

-KSQ

http://ksqphotography.zenfolio.com/

http://ksqphotography.wordpress.com/

I visited Jackson, Wyoming in August 2010 and had the pleasure of touring around the Grand Teton National Park area and the southern loop of Yellowstone National Park.  I had plenty of time to explore and feel like I found many of the top scenic and nature sites in the area.  I put together this pdf file which contains an annotated map of Grand Teton National Park with some of my favorite photography spots.  Each site is designated with a yellow star that you can click on to provide a brief description of the site.  There is also reference to a “Slide #”, of which the slides can be found below the map and possess a few sample photos that I took from each area.  Obviously, there is nothing quite like experiencing a destination for yourself.  But, I hope this resource serves as a mini tour guide to help you prioritize your photography trip to the Jackson, WY and Grand Teton National Park area.  I would be happy to answer any questions you might have.  Enjoy!

Click below for the pdf file or right click to download (WARNING, this is a huge file (17MB) due to the size of the map and photos.  It may be easier to download this file for viewing versus doing so in your internet browser window.  Also you will need adobe acrobat reader to view the pdf file): 

Grand Teton National Park Map and Photography Tour

For more photos from my trip to Wyoming see the links below:

http://ksqphotography.wordpress.com/2010/10/06/nikon-300mm-f2-8-vrii-wyoming-photos/

http://ksqphotography.zenfolio.com/p209984540

-KSQ

http://ksqphotography.zenfolio.com/

http://ksqphotography.wordpress.com/

Feel free to leave your feedback or personal experiences.  Check for future updates for a similar map of Southern Yellostone Park.

Before I get started describing my impression of the Nikon 200-400mm f4 VRII lens with teleconverters, I want to make it clear that I do NOT own this lens.  I was able to borrow it from a friend one moring to do some test shots and get an initial impression.   As a result, all of my findings are based on a single day shooting with the lens both with and without teleconverters including the 1.4x (TC-14EII), 1.7x (TC-17EII), and 2.0x (TC-20EIII).  Please take my results for what they are and read other reviews in addition to this one if you are seriously considering this lens in combination with teleconverters.  For convience, I have included two links to other more detailed reviews at the end of this thread.

Unfortunately, the shooting conditions were less than ideal for this test.  First of all, I wanted to have a living, relatively interesting, and stationary subject to photograph.  The tigers seemed like a good choice at the time, except that they were not as eager to have their photo taken that morning.  As a result, the series of photos below were shot with the tiger in a shaded area of the enclosure.  This resulted in less than optimal lighting conditions for the test photographs. On the other hand, this scenerio mimics the challenges you might be faced with when you are shooting in the field with this lens and teleconverter combination.   Also, I did use a tripod and Wimberly gimbal head for all photos in the series below and all photos were taken with the Nikon D300.  I am considering doing a repeat test in a more controlled environment with better light to help eliminate slow shutter speed from the equation.  This factor was increasingly evident with the 1.7x tele at 580mm equivalent and even more so with the 2.0x teleconverter at 800mm equivalent.  So, as I mentioned before, take the results for what they are.

My Overall Impression: 

Nikon 200-400mm f4 VRII WITHOUT teleconverters :

-Excellent sharpness, color, and contrast

-Immediate and responsive autofocus on the Nikon D300 body

-I found images to be quite good at all ends of the zoom spectrum including wide open at f4

-Even though I used a tripod, I did take some photos handheld and found it manageable

Nikon 200-400mm f4 VRII WITH 1.4x (TC-14EII) teleconverter:

-Overall good to excellent image quality in most photos within a series

-Autofocus remained fast and responsive…I noticed very little change compared to the autofocus without a teleconverter

-This seems to be a rather good combination when you need a bit more reach without too much aperture sacrifice

Nikon 200-400mm f4 VRII WITH 1.7x (TC-17EII) teleconverter:

-Overall fair image quality with a few good shots mixed in…probably more unacceptable photos that keepers

-Started to notice adverse results of camera vibration from slow aperture and teleconverter

-Autofocus was slow but did fuction most of the time, though it had a tendency to hunt

-Personally, I would only use this combination when I absolutely had too

***Nikon 200-400mm f4 VRII WITH 2.0x (TC-20EIII) teleconverter:

-Overall soft images were a results of camera shake artifact from slow shutter speeds and the combination of the teleconverter.  One out of every ten photos was decent enough to post on this blog, but none we that I would brag about.

-Extremely slow to no existent autofocus.  Most of the time it would just hunt without finding focus

-Personally, I would only use this combination when I absolutely had too, or maybe not even then.  Perhaps further testing in better light condition will change this.

***The results at 800mm equivalent with the 2.0x teleconverter are difficult to evaluate and perhaps even down right inconclusive.   Because of the significant camera shake artifact, I personally will not make any conclusions about the quality of this combo, other than saying you will need a good amount of lighting to overcome the aperture limitations.  I don’t blame the tiger for wanting to stay in the shade out of the Texas heat, but it didn’t make my lens-teleconverter test easier.  So, the softness and slight blur in these images is likely due in part to the expected loss in image quality associated with a teleconverter, but then magnified significantly by camera shake (remember I am posting the best example of each).  I think these results do bring up a valid argument of why one should NOT rely on the 200-400mm f4 to be a consistent performer with the 2.0x teleconverter.    Anything less that a brillantly bright scene will leave you with either extremely slow shutter speed camera shake artifact or high ISO graininess, since you are stuck with a maximum aperture of f8 with this combo.  Based on these findings, I personally don’t consider the 200-400mm plus 2.0x teleconverter a realistic option for use in the field for my purposes.   I would have no reservations about using it with the 1.4x teleconverter however.   I am kinda neutral on the idea of using it with the 1.7x teleconverter, though I don’t think I would if I had other options (which I do).  I spoke to the owner of the 200-400mm f4 lens that I borrowed and shared these findings.  She agreed with my observations and added that she only uses the 1.4x teleconverter with this lens for her photography.  Overall, she found the results with the Nikon 200-400mm f4 VRII with the 1.7x or 2.0x teleconverters to be too inconsistent and require too much light for proper function.

Anyway, this is my impression but don’t take my word for it.   See the results for yourself.  Click on the photo to enlarge and click a second time to view at 100%.  I have also added a few high power crops to give you an idea of the detail preservation at higher magnification without the need open the picture fully.

(Below)  Nikon 200-400mm f 4 VRII  at 200mm , f4, 1/60 sec – NO TELECONVERTER

(Below)  Nikon 200-400mm f 4 VRII  at 400mm , f4, 1/80 sec – NO TELECONVERTER

(Below) Close Crop -  Nikon 200-400mm f 4 VRII  at 400mm , f4, 1/80 sec – NO TELECONVERTER 

(Below)  Nikon 200-400mm f 4 VRII  at 560mm , f5.6, 1/50 sec – WITH 1.4x (TC-14EII) teleconverter

(Below) Close Crops-   Nikon 200-400mm f 4 VRII  at 560mm , f5.6, 1/50 sec – WITH 1.4x (TC-14EII) teleconverter

(Below)  Nikon 200-400mm f 4 VRII  at 560mm , f8, 1/25 sec – WITH 1.4x (TC-14EII) teleconverter

(Below) Close Crops-   Nikon 200-400mm f 4 VRII  at 560mm , f8, 1/25 sec – WITH 1.4x (TC-14EII) teleconverter

(Below)  Nikon 200-400mm f 4 VRII  at 680mm , f6.7, 1/15 sec – WITH 1.7x (TC-17EII) teleconverter

(Below) Close Crops-   Nikon 200-400mm f 4 VRII  at 680mm , f6.7, 1/15 sec – WITH 1.7x (TC-17EII) teleconverter

(Below)  Nikon 200-400mm f 4 VRII  at 680mm , f8, 1/15 sec – WITH 1.7x (TC-17EII) teleconverter

(Below) Close Crops-   Nikon 200-400mm f 4 VRII  at 680mm , f8, 1/15 sec – WITH 1.7x (TC-17EII) teleconverter

(Below)  Nikon 200-400mm f 4 VRII  at 800mm, f8, 1/40 sec – WITH 2.0x (TC-20EIII) teleconverter

(Below) Close Crops-   Nikon 200-400mm f 4 VRII  at 800mm , f8, 1/40sec – WITH 2.0x (TC-20EIII) teleconverter

(Below)  Nikon 200-400mm f 4 VRII  at at 800mm, f10, 1/20 sec – WITH 2.0x (TC-20EIII) teleconverter

(Below) Close Crops-   Nikon 200-400mm f 4 VRII  at 800mm , f10, 1/20 sec – WITH 2.0x (TC-20EIII) teleconverter

Here are a couple of links to some more detailed reviews on this lens if you are interested:

Feel free to share your own experience with the Nikon 200-400mm f4 VRII with teleconverters.

-KSQ

http://ksqphotography.zenfolio.com/

http://ksqphotography.wordpress.com/

Now that I have completed my boards exams, I finally have had the chance to actually get out of the house to take some photos.  I only made it 5 miles down the road the our local zoo, but still it’s better than nothing.  Plus, I have always loved big cats, and the Houston Zoo has a decent collection.  These sample photos were taken with the Nikon 300mm f2.8 VRII lens, and show results both with the Nikon TC-20EIII teleconverter and without it.  I did bring my tripod with me this time and this resulted in fewer downright unusable photos as compared to the previous trip without a tripod.   The results at 600mm with the 2.0x teleconverter are still very good in my opinion, especially for “normal” viewing or printing.  I am sure some of you “pixel peepers” will notice that there is some softening and minor loss of image quality associated with the teleconverter that is noticable at full magnification.  But overall this combination continues to produce quality results and I have no regrets about the lens or teleconverter purchases.

Click on the photo to enlarge and click a second time to view at 100%.  I have also added a few high power crops to give you an idea of the detail preservation at higher magnification without the need open the picture fully.

NO TELECONVERTER – Nikon 300mm f2.8 VRII lens only

(Below)  300mm, f2.8, 1/200sec:

(Below) 300mm, f3.2, 1/200sec:

(Below) 300mm, f3.2, 1/200sec (100% crop from upper portion of the above tiger photo):

Another high power crop below to show the detail captured by this lens…

(Below) 300mm, f4, 1/250sec:

(Below) 300mm, f4, 1/320sec:

(Below) 300mm, f4, 1/320sec (100% crop from upper portion of the above cheetah photo):

WITH TELECONVERTER – Nikon 300mm f2.8 VRII with TC-20EIII (2.0x)

(Below) 600 mm (300mm + TC-20EIII), f5.6, 1/125sec:

(Below) 600 mm (300mm + TC-20EIII), f6.3, 1/100sec (notice the point of focus is the nose):

(Below) 600 mm (300mm + TC-20EIII), f8, 1/180sec (notice the point of focus is the nose):

(Below) 100% crop of the nose from the photo above:

(Below) 600 mm (300mm + TC-20EIII), f5.6, 1/125sec (notice the point of focus is the nose):

(Below) 600 mm (300mm + TC-20EIII), f6.3, 1/200sec (great detail in the teeth and jaw):

(Below) High power crop from the photo above…

(Below) 600 mm (300mm + TC-20EIII), f6.3, 1/125sec:

MORE PHOTOS TO BE ADDED SOON…

I finally had a chance to take the Nikon 70-200mm f2.8 VRII lens out and do some more test shots with both the Nikon TC-17EII (1.7x) teleconverter and the Nikon TC-20EIII (2.0x) teleconverter.  ALL of the photos below were shot handheld, and the best photo out of about five shots was selected to post.  Overall, the final results are good with both of these teleconverters and the 70-200mm f2.8 VRII, but not perfect.  Perhaps some “pixel peepers” will not be happy with results from these combinations but overall, I think they do a fine job for the money, compared to larger and more expensive glass.  The photos that were not selected for posting are variable in quality, with most suffering from camera shake artifact since I was shooting handheld in only moderate light.  I will likely repeat these tests again at a later date with a tripod to eliminate camera shake from the equation.  None the less, I was able to get results that I was happy with, even wide open, with both teleconverters.  You can be the judge for yourself.  Also, all photo are UNEDITED, straight from the camera (except watermarking) unless otherwise stated. 

 (BELOW) Nikon 70-200mm f2.8 VRII WITHOUT teleconverter:

(BELOW) 200mm f2.8, 1/320sec (Wide Open)

(BELOW) 200mm f4, 1/200sec

(BELOW) 200mm f6.3, 1/80sec

 (BELOW) Nikon 70-200mm f2.8 VRII WITH TC-17EII (1.7x) teleconverter:

(BELOW) 340mm f4.8, 1/125sec (Wide Open)

(BELOW) 340mm f4.8, 1/125sec – SHARPENING ONLY

(BELOW) 340mm f5.6, 1/100sec

(BELOW) 340mm f6.3, 1/80sec

(BELOW) 340mm f8, 1/50sec

(BELOW) Nikon 70-200mm f2.8 VRII WITH TC-20EIII (2.0x) teleconverter:

(BELOW) 400mm f5.6, 1/100sec  (Wide Open)

(BELOW) 400mm f5.6, 1/100sec – SHARPENING ONLY

(BELOW) 400mm f6.3, 1/80sec

All photos at 400mm equivalent over f6.3 suffered from significant camera shake and were not included.

Below are some additional photos with the 70-200mm f2.8 VRII and teleconverters…

(BELOW) 400mm f8, 1/60sec

(BELOW) 400mm f7.1, 1/100sec

(BELOW) 400mm f7.1, 1/100sec

(BELOW) 400mm f5.6, 1/100sec – SHARPENING  (Wide Open)

(Below) 200mm f2.8, 1/250sec – SHARPENING (Wide Open)

Nikon 300mm f2.8 VRII

http://ksqphotography.wordpress.com/2011/01/24/nikon-300mm-f2-8-vrii-lens-with-tc-20eiii-teleconverter-updated-12411/

http://ksqphotography.wordpress.com/2011/01/03/baytown-bald-eagles-with-nikon-300mm-f2-8-vrii-lens-nikon-tc-e20iii-teleconverter/

http://ksqphotography.wordpress.com/2010/11/17/nikon-300mm-f2-8-vrii-tc-20eiii-field-tests/

http://ksqphotography.wordpress.com/2011/01/03/baytown-bald-eagles-with-nikon-300mm-f2-8-vrii-lens-nikon-tc-e20iii-teleconverter/

http://ksqphotography.wordpress.com/2010/07/19/nikon-300mm-f2-8-ed-af-s-if-vr-ii-lens-review-test-shots/

http://ksqphotography.wordpress.com/2010/07/26/nikon-300mm-f2-8-ed-af-s-if-vr-ii-lens-review-test-shots-ii-7-25-10/

http://ksqphotography.wordpress.com/2010/10/06/nikon-300mm-f2-8-vrii-wyoming-photos/

http://ksqphotography.wordpress.com/2010/10/30/nikon-300mm-f2-8-vrii-with-tc-20eiii-tc-17eii-teleconverters-sample-photos-bad-lighting/

http://ksqphotography.wordpress.com/2010/10/30/nikon-300mm-f2-8-vrii-with-tc-20eiii-tc-17eii-teleconverters-–-sample-photos-goodlighting/ 

Nikon 70-200mm f2.8 VRII

http://ksqphotography.wordpress.com/2010/07/21/nikon-70-200mm-f2-8-ed-af-s-if-vr-ii-lens-review-test-shots/

http://ksqphotography.wordpress.com/2010/10/30/nikon-70-200mm-f2-8-vrii-with-tc-17eii-tc-20eiii-teleconverters-sample-photos-bad-lighting/

http://ksqphotography.wordpress.com/2010/10/31/nikon-70-200mm-f2-8-vrii-with-tc-20eiii-tc-17eii-teleconverters-–-sample-photos-good-lighting/

Nikon TC-20EIII Teleconverter

http://ksqphotography.wordpress.com/2011/01/01/nikon-tc-20eiii/

 http://ksqphotography.wordpress.com/2010/11/17/nikon-300mm-f2-8-vrii-tc-20eiii-field-tests/

http://ksqphotography.wordpress.com/2011/01/03/baytown-bald-eagles-with-nikon-300mm-f2-8-vrii-lens-nikon-tc-e20iii-teleconverter/

 Sigma 150-500mm f5-6.3 APO DG OS HSM

http://ksqphotography.wordpress.com/2011/01/19/sigma-150-500mm-f5-6-3-apo-dg-os-hsm-review/

Accessories

Don Zeck Lens Cap

http://ksqphotography.wordpress.com/2010/07/23/don-zeck-lens-cap/

Lens Coat

http://ksqphotography.wordpress.com/2011/03/28/lens-coat-is-it-worth-the/

Better Beamer Flash Extender

http://ksqphotography.wordpress.com/2010/08/14/better-beamer-flash-extender-review/ 

Lexas Professional UDMA Compact Flash Memory Cards

http://ksqphotography.wordpress.com/2010/10/04/lexar-professional-udma-600x-compact-flash-with-nikon-d300/

-KSQ

Check out more photos at my website :  http://ksqphotography.zenfolio.com/

Feedback is always welcome!

The question about what ”DX” and “FX” formats really means and how it applies to digital camera sensors and lenses can be a topic that is difficult to understand for those who are new (and even not so new) to digital photography.  I was also puzzled by these concepts when I first heard people refer to the “crop ratio” of a DX format camera compared to 35mm standard; how a lens’s magnification was “increased” with DX format cameras compared to full frame, etc.  There are plenty of very good explanations of these topics on the internet, probably many better than the one you are reading.  But this is my way of thinking about it and hopefully after reading a few explanations like this one, you will also understand.   I have tried to simplify the explanation and concepts for all levels of photographer who might be reading this, so if some of the more technical aspects are not precise, please remember this.

First of all, I think it is important to understand the concept that camera sensors are compared to the 35mm format film format (also called ”full frame”).  In digital world, sensors with the same size as these full frame film cameras are referred to as having a FX format sensor.  By definition, FX sensors are the same size as the full frame 35mm film camera had, which measures 36 x 24mm.   You can see a representation of this sensor size on the diagram below that I found on the internet.  So to recap, the terms “35mm”, “full frame” , and “FX” all refer to pretty much the same thing as far as this review is concerned, and for the purpose of this explanation I will use them interchangably.   Currently, full frame sensors are found in FX format “professional level” cameras like the Nikon D3s, Canon EOS-1D Mark IV, or Sony Alpha 900. (ie. they have sensors that measures ~36 x 24mm)

Now it’s also important to understand that there is another smaller digital sensor size used in many, if not most, digital SLRs today  called “DX format”.  These DX format sensors are sometimes referred to as “APS sensors” which stands for Advanced Photo System.  Regardless what you call them, the DX format sensors are defined as having a size of 24 x 16mm.   Any of you math wizards who are reading this might have notived that 24 multipled by 1.5 equals 36 (24  x 1.5  = 36).  So, basically the full frame (FX) sensor is 1.5 times bigger than the DX format sensor.  This is where you get the 1.5x conversion factor that people refer to when discussing FX and DX format sensors (though you also see 1.6x or others multipliers depending on the exact sensor dimensions).  In this case size does matter   Most of today’s popular entry level and semi-professional cameras have DX sensors including the Nikon D300s and Canon 7D.

Below is a nice scale diagram from Art of the Image.com ( http://www.artoftheimage.com/ ) that shows the relative sensor sizes of both Nikon and Canon cameras.  You can check out their youtube video on this subject at:  http://www.youtube.com/user/ArtoftheImage#p/u/48/j2vLJDswULk

One point I would like to make before going on is that all pixels are not created equal.   It always bugs me when someone who knows nothing about photography ask how many megapixels my D300 has (12MP by the way) and then replies, ”oh my point-and-shoot digital camera has more megapixels than that.”  Clearly these peope don’t understand the basics of digital camera sensors, but you will after reading this.  Most digital camera sensors are made up a continuous series of photoreceptors that measure the intensity of light and then convert this measurement into a color.  Details about the color filters that allow only certain wavelengths of light to be measured and how these filters are arranged on the sensor, which allows it to extrapolate the surrounding color intensity is was beyond the scope of this reiew.  But there are plenty of nice in depth reiews on how camera sensors work on the internet.  Here is a nice diagram to give you an idea without a length explanation..    

Anyway, back to the concept of megapixels…A digital sensor with 12 megapixels has 12 million photoreceptors that are then represented by 12 million pixels, usually described in their horizontal and vertical axis (for example 4288 x 2848 is the number of pixels in the width x height of the sensor).  Though both a digital point-and-shoot camera and digital SLR with 12 megapixels have the same number of photoreceptors, these sensors are far from being the same!  The SIZE of each photoreceptor (pixel) is vastly different between a point-and-shot, DX, and FX sensor.  For example, a point-and-shoot camera has a sensor around 8 x 6mm (or smaller) in size, comparent to a digital SLR DX format sensor of 24 x 16mm, or a full frame sensor of 36 x 24mm.  The individual photosensors on the point-and-shoot camera is much smaller in order to be “squeezed” all 12 million onto such a small sensor.  the photoreceptors get bigger as the size of the sensor increases.  The bigger the photoreceptors are, the more sensitive they are to light (I think of it like buckets in the rain.  A point-and-shoot camera has small open buckets that will catch less rain that the larger FX sensor that has large open barrels to collect rain.  This is sort of the same for photoreceptors collecting photons of light.)  This is one major reason why larger sensor cameras perform better in low light situations with less noise caused by increasing the ISO.

Now that we have covered DX and FX camera sensors, how about the camera lenses?  This is actually pretty simple.  DX format lenses are designed internally to project the image onto an area the size of a DX sensor (24 x 16mm).   FX (full frame) format lenses have a different internal design that allow them to project the image onto a larger are the size of a full frame (FX) sensor (36 x 24mm).  This is not to say that you can only use DX lens on a DX format cameras and FX lens on a full frame cameras, because this is not so.  In fact, in general (with some exceptions) either format lens can be used on either DX or FX cameras.  The resulting image will differ in each of these circumstance however, but we are getting ahead of ourselves and there will be more time to explain this concept later.  Take a look at the diagram below to get a better idea of what I was saying in this paragraph.  Notice that the FX lens has a larger circular area which represents the image that the lens is sending to the FX sensor represented by the rectangle.  The DX circle is smaller and represents a smaller portion of the image that is conveyed to the DX sensor represented by the rectangle.

Before I go any further though, it is important to understand that a lens’s focal distance does NOT actually change regardless if it is DX or FX format or shot on DX or FX sensor cameras.  Again, repeat after me… ”a lens’s focal length (which is printed on the side of the lens) does NOT change based on the type camera body you put it on.”  For example, a  60mm DX lens is still a 60mm lens, even if it on a FX body.  Now you might be saying to yourself…”hey wait a minute, you’re wrong.  I was told that a 60mm lens would become a 90mm lens on an FX camera body because of the 1.5x conversion factor thingy”.  Well you would be half correct if you thought this…half wrong because the lens is still “technically” a 60mm lens, and half correct because the image that a 60mm DX lens would produce on a FX sensor camera would be the same as that of a 90mm FX lens shot on a full frame (FX or 35mm) sensor camera.  This is a result of the 1.5x conversion factor from the size difference between the DX and FX sensors.  Still with me?  If not, take time to read over this last part one more time.   Then take a look at the photos below to hopefully, walk you through the logic.

The photo below is from a FX lens paired with a full frame (FX) camera sensor.   Just for the sake of the example, let’s say it is a 60mm FX lens. Because both the lens and sensor are FX format, you are seeing the entire scene that was projected and captured on the 36 x 24mm sensor.

Compared to the photo above, the photo below.  Obviously the photo below is a “closer crop” of the above photo.  There are a couple of scenerios that could be true to give us this crop related to the DX/FX discussion (ie. excluding the fact that I could have walked closer to the mountain   Anyway, the photograph below could have been taken with a 90mm FX lens on a FX camera to give a closer crop of the mountain at 90mm.  However, the other possibility is that the photo below was taken with a 60mm FX format lens on a DX sensor camera.  This latter sceneria with the DX camera sensor would result in an image that would be 1.5 times ”cropped”, and thus the same as the 90mm FX lens on the FX sensor camera (remember 60 x 1.5 = 90).  Read on to discover why this occurs.

Here is how it works.  See the image below.  The yellow outer line represents the full frame (FX) camera sensor measuring 36 x 24mm.  The inner red box represents the size of a DX camera sensor which is 24 x16mm, which is 1.5x smaller than the full frame (I know it says 1.6x but it’s basically the same).  As mentioned before, a FX format lens is designed to project the entire scene onto an area the size of a FX sensor (36 x 24mm).  The FX lens will do this regardless if the camera has a FX (36 x24mm) or DX (24 x16mm) sensor.  In other words, the image that is projected onto a DX camera sensor by a FX lens is actually too big for the sensor.  As a result, all of the image information outside of the 24 x 16mm area of the DX sensor is lost (gone forever), but the central portion of the scene is recorded on DX sensor.  This results in an image that appears cropped by a magnitude of 1.5 times, but without the loss of the file size that would result from actually cropping the full frame photo  in post-processing. Below are some more scenerios to further explain…

FX lens on a FX camera sensor or DX lens on DX sensor:

When you use a FX lens with a FX camera sensor (ie. full frame on full frame) or DX lens with a DX camera sensor, things stay pretty straight forward.  In this situation the lens is designed to project the scene onto either the area of a FX or DX camera sensor, respectively.  So, your 60mm lens would give you the results you would expect for a 60mm lens.

FX lens on a DX camera sensor:

The next scenerio is probably the most common that people run into.  You have a FX lens and shoot it on your DX format camera.  For example, I do this often when I use my FX format Nikon 70-200mm f2.8 lens on my DX format Nikon D300 camera.  This is where the 1.5x conversion comes into play.  In this situation, you have a full frame lens (FX) which is designed to project the entire scene over the size of a full frame (FX) sensor (36 x 24mm).  However, your camera has a 1.5x smaller DX sized sensor.  As a result only the information (or portion of the scene) within the center is actually recorded by the sensor.  The remaining image information on the periphery of the DX sensor is lost.  Look at the photos below to get a better idea of this concept.  As described the FX lens would project this entire scene to what it “thinks” is a FX sensor.  However only the central portion of the scene in the red box is recorded to the sensor and the remaining peripheral image is not recorded.  The resulting photo from this combination would look like the second photo below, where your 60mm FX lens results in an image the same as a 90mm lens.

Based on this, it is easy to understand that many nature photographer often prefer a DX format camera paired with a FX lens to give their lens ”additional reach” without loosing megapixels from cropping.  I mention this because the same image could be aquired by cropping a photo during postprocessing by 1.5x times that was taken with an FX lens on FX camera.  But, this causes you to reduce the file size of your final photo.  For example, if your DX format camera is 12 MP, then your final image is 12MP.  On the other hand, if your FX camera is also 12 MP and you crop the full frame photo to match the 1.5x conversion, then you have lost all the peripheral image and are left with a smaller file (~8MP).  If you plan to print large, this could be a problem.  It’s also worth mentioning that it makes sense that landscape photographers would prefer full frame (FX) lenses on FX camera sensors in order to get the entire scene in the photo, verus having it “cropped” by a DX format sensor.

A DX lens on a FX camera sensor:

The last scenerio is probably less common.  This would be if you have a DX format lens like the Nikon 18-200mm and use it on a professional full frame (FX) camera like the Nikon D3s.  So now, you have a lens that is designed to project only the central portion of the scene onto a smaller DX sensor.  However, we are now talking about a camera with a larger full frame sensor.  The resulting image from this pairing is represented by the photo below.  Now only a DX sized image is being transmitted to the center of the larger FX sensor.  No parts of the scene from outside the DX area (24 x 16mm) is being transmitted to the periphery of the FX sensor.   Fortunatley, most FX cameras have a “DX format” mode and often will automatically recognize that you are using a DX format lens.  One negative to this DX format mode is a loss in total megapixels of the final image  since it is only using information from the central portion of the sensor.  Here is a specific example…the Nikon D3s is normally 12.1 megapixel camera when shooting full frame (FX)   In DX format mode on the D3s, photos are only 5.1 megapixels  (also why it shoots faster frames per second in DX mode).

The final photo from the full frame camera “DX Format Mode” would look like the one below, which is only the central portion of the scene.  Though it would look similar to the FX lens on DX camera photo above, it is a smaller file size because it is only from the central portion of the FX sensor.  This is in contrast with the FX lens on DX camera photo which would still be the entire file size since it was taken from the entire DX sensor.

Well I hope that makes this topic at least a little more clear to some…  Feel free to leave comments or feedback.

Also, I must admit that I shoot exclusively with DX format cameras at the time of writing this, so the photo examples were all taken with a DX camera (Nikon D300).  Photos were cropped to give them the correct proportions for this review, but all of  the concepts are still true.  I put this “disclaimer” at the end so as to not confuse anyone before reading.  I am currently waiting to see what line of cameras Nikon will come out with next before deciding if FX is right for my needs.

Thanks for reading

KSQ

http://ksqphotography.zenfolio.com/