Wednesday, March 28, 2012

There has been some discussion of late about the Reflex Lens, with some who like it or are neutral and others who have had them and then gotten rid of them. This lens is also called a Mirror Lens or a Cat (short for Catadioptric) lens. It is for all intents and purposes a telescope built to mount on a camera.

With this lens the image passes through the front element and strikes a parabolic mirror at the back of the lens. It is then reflected forward to a second mirror usually mounted in the center of the front element of the lens, which reflects the light back through the opening in the back of the lens to the sensor (or film).

It has some major draw backs, but also has some very good features for those willing to work with the lens and live within its limitations.

Cons:
- out of focus highlights tend to look like donuts
- It has a very short depth of field due to being a telephoto lens with a fixed aperture. In the case of the one I use it is f8 only.
- Changes in exposure have to be accomplished with changes to the shutter speed, changing the ISO on the camera or using neutral density filters (which in my case are 37mm and screw onto the back of the lens).
- A good support is great asset, though the lens is light enough for hand held work.
- Due to the very short depth of field precise focus is a must
- The angle of view of the lens is only 5 degrees
- Focusing the lens can be difficult because the relatively small aperture (f8 or f11) makes the field of view darker than a lens that focuses at full aperture then stops down for the shot)

All of the cons make it a difficult lens to use. There are some pros that I found compelling, and thus the reason I choose to keep mine.

Pros:
- Very inexpensive for its focal length. Used they can be less than $300.00 (I paid much less and the glass was virtually pristine).
- Very light weight for a 500mm lens, can be used hand held with a steady hand and good shooting technique
- On a Nikon DX camera is the equivalent of 750mm
- The design virtually eliminates chromatic aberration giving the lens excellent sharpness and contrast when properly focused
- The donut shaped blurs of the out-of-focus elements can give a striking effect to the photograph in the right setting
- The very shallow depth of field can be very effective in isolating the subject when the lens is focused correctly

As you can see the cons outnumber, and for many photographers, out weigh the pros. Still for those willing to use the lens within its limitations it can be very effective. For example taking "predictable sports action shots", that is shots where the photographer can prefocus the lens and/or use trap focus techniques.

It can also be an effective portrait lens, though that is best done on a full frame DSLR due the crop factor on APS sensors. The subject is static as is the camera therefore precise focus can be obtained and maintained. The subject can be completely isolated from both the foreground and background. This is because of its very short depth of field. Plus the nature of the lens gives an extremely high resolution and contrast.

Below are some samples of my work with a Reflex lens

I took this first photograph of an Aligator watching me watch it. I used a Nikon D300, hand held, and had the 500mm f/8 Reflex C lens mounted on the camera.

The photograph was cropped but no sharpening has been applied. I was pleased with how crisp and clear the features of the Aligator's eye were (they are even better in the unedited RAW version). This shot was made possible because of the static nature of the subject giving me time to focus the camera and the bright daylight. To hold the camera steady I held the lens with my left hand, the camera with my right, braced both arms against my chest, and controlled my breathing with a gentle continual press of the shutter release (using my best marksmanship techniques).

My next shot was taken of the Syzygy Moon. I had the D300 set up as follows. On a tripod, -3EV exposure compensation, 500mm f/8 Reflex Lens, ISO 200, camera set to mirror up mode. Of note is that I never saw the jet and contrail while I was taking the photograph. It was only after I had actually down loaded the shot from the card to my computer that I saw it. I did some sharpening on the jet itself to bring it out more. However the details of the moon and the contrail have not been sharpened. The only other adjustment was a crop of the photograph.

The final shot was taken the day I bought the lens. Again I used the D300 and a tripod for the shot. I was tracking one squirrel when I pressed the shutter. I missed the squirrel I was tracking but found a second squirrel I had not seen before in the photograph. Again the shot was made possible by a static subject and bright day light.

None of these are spectacular shots per se. I have much yet to learn in photography, and on how to effectively use the Reflex lens. Yet all of the shots could have been winners with better technique and practice on my part, and none of the shots would have happened without a 500mm lens, in my case Reflex lens. I could not then (and still choose not to) afford a standard 500mm lens, and my Reflex lens cost me $175.00 used in 2008.

I for my part see no reason to discard the lens, yes it is difficult to learn, but it can be learned and used effectively.

More technical information and couple of samples of work with the Reflex family of lenses can be found at the website below.

http://www.mir.com.my/rb/photography/companies/nikon/nikkoresources/reflex/index.htm

Thank you for reading my thoughts,

Ed Ford

Tuesday, March 20, 2012

Under the Bridge

For our recent competition assigned subject we had to shoot bridges. One of my goals in an assigned subject is how to fulfill the assignment without doing the same thing everyone else in club was doing.

After some thought about bridges in general I chose to go to the bridges that cross  the Brandywine Creek into Wilmington. The two I chose to work were the I95 Bridge and the North Washington Street Bridge. Again, trying something different I went under the bridges and chose to take my photographs of the structure of the bridge. The primary issue I faced was keeping it clear that I was shooting a bridge. If the judges can not get that concept immediately in the very short time they have to view the photograph the scores may be low. In other words it had to be obvious that it was a bridge.

In order to get the shots I used a wide angle lens, in this case the Nikkor AF-S 10-24mm DX lens on a Nikon D300. I did try to use a fill flash but was too far way from my subject to make the flash effective so the images took some post processing working the shadows and highlights to bring out the detail of the structure without blowing out the highlights. I also wanted very much to bring out the color of the underlying structure of the bridge to give the photo some life. The efforts were successful. The three photos below were all accepted by the judges - the first for the for projected competition and the last 2 for the print competition.

Projected Image Competition:

Under the Bridge

Print Competition:

Over the River Looking up


Support your local Bridge

Ed Ford

Tuesday, October 25, 2011

My first post...

Hello world....sorry but as a developer geek I have to start there since this is my first post to this blog. I have been asked to try and contribute occasionally to support DPS (as we tend call Delaware Photographic Society) which is my home photo club - and a great one at that.

I have been thinking about what might interest the wide world out there and since I am one of the club's Photoshop folks I am thinking maybe I might post about assigned subject or creative images I've made for our club internal competitions and other purposes.I'll start with a simple one to get things rolling.

Image entitled 'Focus'
This shot is titled "Focus" and a larger version can be seen here. It was taken for an assigned subject competition with the subject of "Selective Focus". It is a macro shot using a 50mm f/1.4 lens on an 8mm extension tube and I actually had to stop down a bit to get the foreground and background text at a sensible level of out-of-focus. At a fully open f/1.4 the text was so blurred it was almost not visible. I used a focus rail on a tripod to mount the camera to ensure a sharp image...exposure was 0.1 secs using available light.

Post-processing here was simple. Color balance and initial sharpness were adjusted using Adobe Camera Raw then some gentle noise reduction with an edgemask to protect the edges. Some gentle color correction and contrast enhancement then gave me my "digital negative". Creative additions consisted of some selective shadows (in the foreground and background) and selective sharpening (in the centre) to further emphasize the main subject...the word 'Focus'.

OK...we'll see how this goes and watch this space for more in the future.

Al G

Wednesday, November 25, 2009

Photo Restoration Services Do Amazing Work

If you've ever had a treasured photo damaged, or would like that old photo of Great-Great-Grandmother restored to its original condition, consider an online restoration service.  ScanCafe is one such service and I recently asked them to restore an image of my cousin.  Her mother asked me to see what I could do with it since she knew I was into digital photography.  Well, when I saw the print, I knew it was beyond my abilities so I uploaded it to ScanCafe.   Just scan the photo at 600dpi or greater and post it for a quote which is usually between $10 and $40 depending on the amount of time they expect the restoration will take.  The response will take a few days. With my photo, I was expecting the price to be close to the top end of the scale but the quote was for $9.95, the exact opposite.

Before
After

There are several online and traditional restoration services. If you would like to try ScanCafe, the quotes are free, the prices are very reasonable and the results are stunning.

John D.

Sunday, August 23, 2009

Welcome to the DPS Blog


Welcome to the new Delaware Photographic Society Blog!

The blog will be our way to get news and commentary published by our most experienced members.

The Delaware Photographic Society was established in 1931 and is still going strong. We have over 250 members of all ages with most of the membership living within 50 miles of Wilmington, Delaware. But, we currently have members from nine states.

If you're looking for information on the club's activities and photo galleries, please visit our web site at www.delawarephotographicsociety.org.

We will also be unveiling a new site specifically for the Wilmington International Exhibition of Photography which is hosted each year by DPS. The new web site will be operational in time for competition entries.

Entries this year will be fully automated with an online fee caculator, payment and image upload capability.

Stay tuned to this blog and visit the new website when it opens.