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Photography Question 
Irene Troy
BetterPhoto Member Since: 5/27/2004
 

Teleconverters


I am trying to increase the reach of my 200-500mm lens and am considering purchasing a 2X teleconverter. But, I need some help understanding some of the mechanics involved. So, real stupid question here; by how much does the converter increase reach – does this make the lens capable of focusing at 750mm or is it 650mm? The other question is - how will a teleconverter affect sharpness (if at all)? The lens for which I want this converter was made by Tamron. The camera is the Konica-Minolta 7D or the Minolta 9 –SLR. The converter I am looking at is made by KM. Will the fact that the lens is made by Tamron cause a compatibility issue? Thanks folks. Oh, and unless I hit the lottery, getting a prime 600mm lens is out of the question for some time!

Irene


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8/3/2005 1:07:05 PM

 
Michael H. Cothran   There are two popular tele converters available today - 1.4x and 2x. Simply multiply your lens' focal length(s) by this factor to determine what your new focal lengths will be.
For example, your 200-500 zoom will now become a 400-1000mm zoom with the 2x converter, or a 280-700mm zoom with a 1.4x converter.
Teleconverters run the gamut in quality. In effect, you get what you pay for. Cheap converters can be fun to use, but quality flies out the window. The best tele converters available are those that are "dedicated" to a particular lens or lenses. The price of the tele converter should be a first-hand indicator to its quality. If your lens is a Tamron, I would first look at Tamron's own converters.

Image quality will always deteriorate to some degree, the amount is dependent upon the quality of the converter, and how well it is matched to your lens.
As long as both the lens and converter are made for your Minolta 7D, you should not experience any compatibility issues.

Here are three issues about using a 2x converter on a long lens such as yours:

First problem - Camera shake, especially at 1000mm will ruin more shots than not. It will be your worst enemy, and even with a super great heavyweight tripod it will be the challenge of your life to steady this rig.
Second problem - Focusing. The longer the lens, the greater care you will need to apply to focusing accuracy, simply because you have so little DOP at long focal lengths.
Third problem (or issue)- Light loss - a 2x converter loses 2 full stops of light, while a 1.4x converter loses 1 full stop. What this means is that if your lens is, for example, f5.6 wide open, with the 2x converter it will be the equivalent of an f11 lens wide open (although your camera reading will still show "f5.6," but with a shutter speed 2 steps slower.
You don't need to apply any compensation here, as your in-camera meter will automatically adjust. This can become an issue in dimmer lighting situations.
My recommendation is this - If the 2x converter is within your budget constraints, buy it, and have fun it. Maybe someday you CAN afford that prime 600/4 lens. However, if it's a $29.95 internet special, you might need to be a little forgiving on the image quality it produces.
Michael H. Cothran
www.mhcphoto.net


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8/5/2005 9:25:50 AM

 
Irene Troy
BetterPhoto Member Since: 5/27/2004
  Thank you, Michael for your very detailed answer. After thinking about it and after reading what you say here, I am trying to figure out my next step. This all started because I get really frustrated when I am trying to photograph wildlife at a distance that is greater than the reach of my 200-500mm lens. I have learned the hard way that even if the stated reach of this lens is 500mm – at the fully extended length the sharpness of my image can be barely acceptable. According to your info adding a 2X TC will also adversely affect sharpness at the maximum focal length. Since I use this lens primarily to photograph wildlife, often moving wildlife, it is important that the focusing speed by fast and accurate. On this same thread, Jon Close (I don’t know where his post disappeared to) advised that a TC can make focusing difficult, again at maximum focus length. I am currently taking a class with Brenda Tharp and she, also, told me much of what you and Jon have told me. The consensus seems to be that while a TC can increase my ability to focus closer on distant subject, it comes at a cost in sharpness and speed. I think that what I may do is to visit my local camera shop and see what the TC does with this lens and whether or not I can live with the inherent problems associated with using a TC. Life would be much simpler if I won the lottery and could go out and buy that $7000 Minolta 600/4 lens I really want!

Thanks again!
Irene


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8/5/2005 1:15:44 PM

 
Bob Cammarata
BetterPhoto Member Since: 7/17/2003
  Irene,
The limitations of a 2X T/C have been noted and I can certainly concur.

What type of wildlife are you attempting to capture with your 200-500mm lens?
Is there any way that you can get closer to your subject to negate the use of lens extension?
Many species in the wild can be approached close enough to achieve full-frame images at 500 mm.
Others can be "coersed" into shooting range by bribing them with tidbits of food...(If it's legal to do this. In many State and National Parks this practice is frowned upon.)

I've used a 2x converter but only with a fast prime telephoto and with a tripod. The results were OK but were lacking a little in sharpness and clarity.


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8/5/2005 3:58:46 PM

 
Irene Troy
BetterPhoto Member Since: 5/27/2004
  Hi Bob and thanks for your input. What started me down this entire road (as-it-were) was an increasing frustration with attempts to capture images of fledging birds. I am lucky enough to live within less than 5 minutes from a well known wildlife refuge that is known among serious birders for some of the best species observation in North America. I have few problems in my attempts to capture images of larger wildlife – think deer, coyote and fox – but continued problems attempting to capture images of birds in flight – particularly fledglings leaving their nest. Just the other day I was up very early (about 4:30am) to watch as young Osprey left their nest to begin their first real hunt. I was set up in a great area, well hidden from the birds, and all ready to capture some terrific images. Well, my lens simply did not offer the focusing distance I needed in this and similar situations. The other problem I keep encountering is that of speed of focusing and speed of shooting. These two problems are more easily solved – I go back to my film camera, with its motor drive and its faster focusing speed. The distance problem is not easily resolved. The 2X TC may help, but from everything I am reading, it may just present some new issues.

BTW: the ethics of luring wildlife with food are hotly debated among naturalists and photographers. I was always taught that using food to lure wild animals is wrong, but, I also know some really good people – both naturalists and photographers – who will use food in some conditions. I have never done it, but under the right conditions I might consider doing so. Of-course, on the refuge it is prohibited, for good reasons – people can be idiots! I always think of the scenes I have seen in Yellowstone (I grew up right outside of YS): people trying to lure bison close enough so that they can photograph their children standing next to the bison; people trying to do close ups of bears and other similar lunacy. I know, this is not what you hade in mind at all!

I think that it is probably coming down to my saving my pennies and trying for that prime 600mm lens. Thanks again!


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8/5/2005 5:22:56 PM

 
Bob Cammarata
BetterPhoto Member Since: 7/17/2003
 
 
  Tufted Titmouse
Tufted Titmouse
Nikkor 180 mm, KR-64, Quantum Radio slave remote.
© Bob Cammarata
Nikon FM2 Manual E...
 
  Sikas
Sikas
Nikkor 180 mm, Provia 100
© Bob Cammarata
Nikon FM2 Manual E...
 
  Sika 4
Sika 4
Nikkor 180 mm, Provia 100
© Bob Cammarata
Nikon FM2 Manual E...
 
  Pintails in Flight
Pintails in Flight
Blackwater National Refuge
(Nikkor 180 mm, TC-201 tele-converter, Provia 100)

© Bob Cammarata
Nikon FM2 Manual E...
 
 
Irene,
My reference to luring with food was limited to back-yard "fuzzies" and/or song birds at a feeder, which are considerably tame anyway.
The tufted titmouse photo was taken at a feeder (just out of frame to the right).

For large grazing animals in national parks and wildlife preserves, the winter months can be the best time. The crowds (and misquitos) are gone and the larger mammals are more active during the daylight hours.
The two deer photos were taken last winter from inside my vehicle with a 180 mm Nikkor lens.

For predatory mammals and most birds...especially raptors, you will definately benefit from more reach.
As I mentioned before a 2X can produce acceptable results when used in conjunction with a fast tele with good optics.
The pintails were shot hand-held with a 2X and the 180 mm. While not as sharp as the lens by itself, this less costly alternative produces passable images,...while I too aspire to one day own a prime super-telephoto.


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8/5/2005 6:31:51 PM

 
Irene Troy
BetterPhoto Member Since: 5/27/2004
 
 
 
Hi Bob and thank you for the continuing help. I figured you were talking about back yard birds and as you put it, “fuzzies” when you spoke of using food. We keep a number of feeders outside year around and attract many varieties of birds. The Oriole image was made from the kitchen window using my 200-500mm and came out acceptably sharp. The image of the white tail was made in the refuge I spoke about and is also acceptably sharp. If you look at my gallery you will see images of wildlife – deer, elk, big horn sheep and pronghorn – all made with this lens and most were made with the lens attached to my car pod and shot through the open car window. My favorite time of year to visit Yellowstone and Glacier is late fall and into the winter. I don’t “do” crowds and by then most of the crowds are long gone. I’m one of those weird people who actually prefers winter to summer and not so great weather to sunny, clear days! I try every year to get back to Yellowstone/Glacier and that area during late fall or winter when it is much easier to find and photograph wildlife without competing with crowds of tourists.

I find raptors difficult to photograph anyway – I seriously suspect that this has little to do with equipment and much to do with inexperience. I did make the red tail image with my current lens and once again, it is acceptably sharp. I think I will try the 2X TC and see what happens. Thanks again for your help.

Irene


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8/6/2005 7:59:58 AM

 
Irene Troy
BetterPhoto Member Since: 5/27/2004
 
 
 
Hi Bob and thank you for the continuing help. I figured you were talking about back yard birds and as you put it, “fuzzies” when you spoke of using food. We keep a number of feeders outside year around and attract many varieties of birds. The Oriole image was made from the kitchen window using my 200-500mm and came out acceptably sharp. The image of the white tail was made in the refuge I spoke about and is also acceptably sharp. If you look at my gallery you will see images of wildlife – deer, elk, big horn sheep and pronghorn – all made with this lens and most were made with the lens attached to my car pod and shot through the open car window. My favorite time of year to visit Yellowstone and Glacier is late fall and into the winter. I don’t “do” crowds and by then most of the crowds are long gone. I’m one of those weird people who actually prefers winter to summer and not so great weather to sunny, clear days! I try every year to get back to Yellowstone/Glacier and that area during late fall or winter when it is much easier to find and photograph wildlife without competing with crowds of tourists.

I find raptors difficult to photograph anyway – I seriously suspect that this has little to do with equipment and much to do with inexperience. I did make the red tail image with my current lens and once again, it is acceptably sharp. I think I will try the 2X TC and see what happens. Thanks again for your help.

Irene


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8/6/2005 8:04:13 AM

 
Bob Cammarata
BetterPhoto Member Since: 7/17/2003
  Irene,
I too prefer the winter months over summer,...especially when visiting the "touristy" locales of my usual haunts.
People are great but they have no business being in a wildlife photo.
(Unless something happens to be chasing them.) :)

I too enjoy shooting from my vehicle. Nature has instilled a fear of mankind in most species but somehow they feel that our machines will do them no harm.
I've gotten incredibly close to deer and other skittish critters in winter but as soon as I opened the door to my Jeep they would take off like bandits.


Have you ever tried working with remotes?
This can be a fun winter project and can produce some really great song bird portraits.
The titmouse photo was taken while I was sitting in my warm house... watching the activity at the feeder from the kitchen window.


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8/6/2005 5:10:54 PM

 
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