Hot answers tagged teleconverter
19
The two devices do entirely different things.
Extension tube:
An empty tube which moves the lens further away from the sensor.
The point is that as you focus on closer and closer objects, the focused image (which you want to place on the sensor) moves further from the lens. Eventually the lens reaches the limit of its travel and closer objects focus ...
13
TL;DR version: Teleconverters don't affect depth of field at any given distance. They literally transform your 300 f/2.8 lens into a 600 f/5.6 lens. Any 600 f/5.6 lens, teleconverted or not, will have the same depth of field as a 300 f/2.8 lens.
There's a lot of confusion about the relationship between depth of field, aperture, f-stop, and focal length. In ...
11
In general this is what you can expect for using a 2x extender:
Lower max aperture — which may cause your camera's AF system to stop working, or at least perform worse.
Darker view finder
Loss of sharpness, especially at the corners
Loss of color contrast
Increase in color fringing and chromatic aberrations.
The effects of the optical degradation will ...
9
You can use a teleconverter with some zoom lenses -- but not with your Sigma. In fact, most of Sigma's higher-end zooms are specifically designed to work with a teleconverter (Sigma's), and a couple of them actually perform slightly better in some respects (specifically in terms of chromatic aberration and vignetting) with the teleconverter added than ...
9
This is going to depend very much on what camera body you are using. Canon cameras do not focus past f/5.6 unless you are using a 1-series body (or are willing to do some warranty-voiding pin taping to force f/8 AF on unsupported bodies...which is usually a moot exercise anyway). Slapping a 2x TC onto a 70-200 f/4 is going to give you an f/8 aperture, and ...
8
I'm assuming you mean this: Raynox DCR-2025, Pro 2.2x Telephoto Lens for Digital Still Cameras. In this case, beware of the word "pro", as it doesn't mean anything — Raynox just sticks that on all of their similar products to make them sound fancier. It's also disingenuous and confusing for Raynox to call this a "telephoto lens", because it isn't really.
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7
Yes they work, I'm sometimes using one with my 100mm non-L macro with good results. However, there is a caveat: Canon and Sigma teleconverters do not work because they physically do not fit. There is a protruding bit at the front of the converter that fits into a corresponding cavity on the back of the lens - and only certain L Canon lenses have this. This ...
6
The depth of field is that of a F/5.6 lens in the example you state.
Yes, the aperture has not physically changed. However, the ratio of aperture to focal-length has increased.
Therefore, light rays reaching the sensor will be less oblique. That results in increased depth-of-field.
6
The lens mounts have a specification over the maximum distances that elements can extend backwards - with EF-S lens, this is further back than on an EF lens. With an extender, which differs from extension tubes that don't contain any optical elemetns, the situation is reversed -- compatible lenses cannot go as far back as the normal EF lens specifications ...
6
With the Pentax option, you're basically getting "close" with the manual lens using manual focus and then using the AF of the camera to move the lens elements in the teleconverter itself to adjust for more precise focus. Bear in mind that the TC is a lens itself...
At any rate, it's not perfect answer for making a manual lens do AF, but for the right sort ...
6
Basically tape the last(left) three pins of the converter. EXIF distance data will likely be lost for most lenses.
You will find your answer at this link: Fred Miranda Tips Page
As quoted from the site:
Just place a small transparent piece of tape on the last 3 pins of the converter. The tape should be placed on the left hand side of the converter ...
6
Go for the long lenses if you can. On Safari, you will be taken out when animals are most active which is at dawn and around dusk. Given the lack of artificial light, it will be dimmer than those times in the city. Meaning you will be shooting wide-open and as wide as possible to get shutter-speeds fast enough to freeze the animals.
Otherwise, the 400mm ...
5
What I Would Make
You know what you want. A bar that has a slide mount tripod plate on one side, and two screw mounts on the other, one of which is adjustable height.
Sounds like a chunk of t-slot bar would be ideal. To make the vertical risers two angle brackets and a chunk of the t-slot can be used. This plan will require a drill and a hack saw. When ...
5
Can't add anything to Itai's excellent succinct explanation of what's going on, however I'll introduce a proof by Reductio ad Absurdum:
Suppose that using a teleconverter extended the focal length and as a result let in less light but without affecting the depth of field. As well as making a 600 f/5.6 a manufacturer could take an existing a 300 f/2.8 design ...
5
An extension tube has no optical components. It's role is to move the lens further away from film/sensor. This results in a "closer" focus, which makes it more ideal for macro photography. The downside is that with some extension tubes you lose AF, and with all tubes, you require more light for the exposure, as light falloff becomes an issue.
A ...
5
As I am not a Nikon user (nothing against Nikon though, excellent gear), I can't offer any specific answers. However, when it comes to using a teleconverter, you will really want the fastest lens you can find.
Tacking on a teleconverter tends to reduce your effective aperture. I know that with Canon cameras (and I believe this is the case with Nikon bodies ...
5
If you are going on a safari, then you will really want to get the longest lens you can get your hands on. It won't be all that often that you are close enough to photograph frame-filling animals at 400mm, and generally speaking the farther you can stay from the wildlife the better (for both you and them.) In this respect, I highly recommend you rent, rather ...
4
I don't know about nikon, but I did the same thing on the Canon side. I had a junk 70-300 lens, and decided to upgrade. I ended up buying the 70-200L IS, plus the 1.4 teleconverter. You just have to, they're both white :) Since then, I've used the lens itself quite a bit - zoomed all the way out for portraits, zoomed in for some sports and wildlife. I ...
4
There is also a huge difference between an adapter that screws onto the threads at the end or your lens and a professional grade teleconverter that fits between your body and lens. You still lose a lot of light, -pro teleconverters will usually tell you how many stops specifically- but the optical quality of pro TCs can still make for minimally distorted ...
4
Do you have any suggestions on how I can manually focus with the three stop light loss without losing the flexibility of working handheld?
If you'll excuse the trivial level of the answer - which works well for me - I on occasion use an LED torch for night lighting for focusing purposes either when the flash focus assist light is ineffective or I'm not ...
4
I shot for a number of years with the 100-400. Very nice lens. I retired it in favor of the 300F4 with a 1.4x tele. That's about the same cost as the 100-400 (maybe a bit less), and it's sharper, with faster AF. All in all, a much superior wildlife/bird lens around 400mm at a good price.
I did some experimentation with the 2X tele and the 70-200 F2.8 IS, ...
3
Depending on how much experience you do have with wildlife photography you might realise that longer is often better.
I have been looking at the 100-400 myself, but recently I tried the Sigma 150-500 DG OS HSM and was impressed. It's longer and cheaper, but since I haven't tried the Canon 100-400 myself, I can't really compare them. You might want to look ...
3
I think you are mostly likely wasting £6. A teleconverter is going to cause some image degradation, and stacking two of them more so. Even with a top notch lens and teleconverters. With inexpensive TC's off eBay I think the likelihood of the images being usable is slim. The corners will most likely be very soft, and as you are increasing magnification, ...
3
One or more extension tubes (or a bellows) will get you greater magnifications without introducing extra optical elements that may degrade image quality. You will always pay for magnification with light loss, though. Whether you use a teleconverter or simply increase the lens extension, you are reducing the effective aperture of the lens, while at the same ...
3
The other answer is fantastic, but as a practical matter you should also know about the Sigma teleconverter compatibility chart:
http://www.sigmaphoto.com/sigma-lens-teleconverter-compatability-chart
If you have a Sigma lens and it is not on there, you cannot use a TC with it. The chart is also helpful to understand if you'll be able to use AF with a ...
3
It's a physical limitation with the Canon 2xII, where the front element of the extender sticks out in front of the bayonet where your lens will fit. You may be able to find an alternative manufacturer's extender which has a different front-element design which will work with other lenses.
Even Canon's extenders can work with lenses you may not expect: the ...
3
I think the most flexibility is found with the 600 f/4 and 1.4X (2X would be good too if you can). If anything is too close for the 600 then you can use your existing 70-300L.
The 600 + 1.4X is comparable in quality/speed to the bare 800 f/5.6L
see:
http://www.fredmiranda.com/forum/topic/1153613/0
3
You say that the thing calls itself a "58mm Pro Digital Precision Tele converter 2.0x AF"... the 58mm part calls for some thought. Just what kind of product is this? Is it a teleconverter, a thing that you mount between the lens and the camera body, or is it a kind of secondary lens that you screw on to the front of your 55-300? (If the latter, it should ...
2
Some traditionalists would probably want to stone me for suggesting this, but have you thought about cropping as an alternative? Using the 70-200 2.8, you can cut off the outside areas of your photo to digitally zoom in on your subject/scene. The D5000 is a 12.3 megapixel camera, and it can withstand some cropping without any noticeable degradation in ...
2
I believe that the 70-200 accepts a few specific 1.4x TCs quite well.
But, the 70-200 and 70-300 are totally different beasts. One is a inexpensive, slow consumer lens and the other is an expensive, fast pro lens. And good TCs are not cheap (more than the 70-300 alone?).
Also, there's some confusion about how much aperture loss there is from a TC. A 1.4x ...
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