19

This is really simple when you think about it. The additional element changes the focal length of the lens, without changing the apparent size of the aperture. That means that the relative size of the aperture decreases, so the f number does in fact actually change. (If this is unclear to you, see the bit about f numbers in this other answer.) This is also ...


14

The blue halo is often referred to as purple fringing. It is caused by chromatic aberration. According to Wikipedia: There are two types of chromatic aberration: axial (longitudinal), and transverse (lateral). Axial aberration occurs when different wavelengths of light are focused at different distances from the lens, i.e., different points on the optical ...


11

With any lens of greater than 300mm focal length on a full frame camera you're probably not going to get results you're happy with shooting handheld. On your 1.6X APS-C camera, the same angles of view are provided by any lens 188mm or longer. It is true that lenses such as the Sigma and Tamron 150-600mm telephoto zooms are weakest at their longest focal ...


10

You will have to manually focus by moving the focusing ring on the lens. Using the center focus point to focus and then recompose is still considered autofocus. Even if you have manually selected which autofocus point the camera uses, the camera is still focusing the lens, not you. You'll also lose more image quality with a 2X than with a 1.4X. This will ...


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 ...


9

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 ...


9

I have both a 70-200 (2.8, non-IS), as well as the 135 and a 1.4x (II). This is a very difficult question to answer because it depends on your use. For me: I enjoy the flexibility of the 70-200 for certain types of shooting, e.g. action sports and other activities where I'm not easily able to zoom with my feet and/or it's a pain to fiddle with extenders. ...


9

I have used the exact setup you are using. I found that the 2X Teleconverter iii worked wonderfully with the 70-200 f/2.8 IS II on the 5D Mark iii. I actually tested it in far harder conditions (shooting a wedding in a relatively dimly lit gymnasium) and it worked quite well. Particularly since you will be using the shorter focus distance setting, I ...


8

Well, the main thing is that crop factor doesn't really affect focal length. It just affects the field of view by making it narrower. So, what you really have is a 400x1.4x => 560mm lens combination on a crop body, which has the same FoV that an 896mm lens would have on a full frame body. So, unless you shoot full frame enough to translate focal lengths to ...


7

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 F/2....


7

The Canon extenders will not physically mount to an EF-S lens. Even if you defeat the keying the front part of the EF 2X (any of the three successive versions) would extend into the rear of the EF-S 55-250mm and almost surely contact and damage the rear lens element or the front element of the extender or both, at least at certain focal length and focus ...


6

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 ...


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

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 ...


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 when ...


6

Your basic assumption about teleconverters is right. But you haven't done the math: 1/2" is 6.4mm x 4.8mm—doubled is still only 12.8mm x 9.6mm. OTOH it's not unheard-of for tiny format lenses to have image circles well larger than their specification.


6

It depends on how you define "work". And it depends on the lens with which you are working. If it means everything will work the way it does as you are now shooting with only the EF-S 55-250mm f/4-5.6 lens the answer is no. Autofocus: Because your T3 limits your auto focus system to lenses with maximum apertures of f/5.6 or wider, even a 1.4x teleconverter ...


6

How can I modify my NIkon D5500 so I can make a vintage lens auto focus? You can't. I learned that using a TC-16A AF Teleconverter 1.6X might help ... Whatever you learned is probably wrong. From my googling it looks as if the TC-16A was designed to turn AIS lenses into AF lenses (i.e., an interim step to add electronic communication and the physical ...


6

From Nasim Mansurov, the author and founder of Photography Life. Teleconverters do not affect optical characteristics of lenses – they only magnify the center portion of the frame. This means that if one were to use a telephoto lens with a short minimum focus distance, it could be used as an excellent option for extreme close-up / macro photography as ...


6

Theoretically, optically, it would work (for low-quality values of "work"). Yes, the focal reducer would give an extra stop of light. But because the 2x teleconverter is responsible for 2 stops of light loss, you'd still net 1 stop of light loss. Aside from the optics math, there are some real practical problems with this approach. Depending on exactly ...


6

Although very little (single digit percentages) light is lost to a teleconverter, the ratio of entrance pupil to focal length grows proportional to the magnification of the telecon. For example, if a 100mm f/2 lens has a 2x teleconverter attached to it, the lens will effectively become a 200mm f/4. This is because the lens will always have a 50mm entrance ...


5

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 ...


5

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, ...


5

Simple answer: DO NOT USE A TC ON THAT LENS!!! I own that lens myself, and I have tried to use it with several TC's, including Canon's Mark III 1.4x and 2x TC's, as well as a Kenko 1.4x PRO 300 DGX TC. Neither of the Canon ones work...even the 1.4x...due to the lack of f/8 AF on anything but Canon's 1D series bodies (1D X excluded). The Kenko 1.4x TC ...


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 ...


5

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 ...


5

I don't think it would work with the first party teleconverters from Canon simply because of how they are constructed. There is a rubber ring that sticks out into the lens which helps prevent bleeding from rays that aren't being used, but it also won't fit in the backside of the teleconverter. There also isn't any correction profiles for the electronic ...


5

Yes: Remember that the f-stop is a relation between your aperture and the focal length. In theory if you have a f/1.0 50mm lens, that means that you have an aperture of 50mm. If you double the focal length (2x) the relationship reduces to half, so it will be a f/2.0 aperture. There can be some other factors as the quality of the lens elements, the ...


5

With a ideal 2x teleconverter, you will be 2 f-stops down from what the lens is set to. Think about the basic physics and this should be clear. A 2x teleconverter makes the dimension of anything in the image 2x larger. Something that would result in a 1x1 mm square with the bare lens results in a 2x2 mm square with the teleconverter. That 2x2 mm square ...


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