Teleconverter or Crop?

[gckless]

Hey folks, question about long telephoto work. Is it better to use a teleconverter or crop your photo down? With a teleconverter, you could get the framing right, but at the cost of speed and noise (any other cons?). Without it, you would have a probably better quality photo, but would then need to crop down. Which would you rather do, and why?

If you need an example, just go with a 400mm f/4, either using a teleconverter or cropping down.

 

[480sparky41 41]

The answer is: It depends.

There's far too many variables to proffer a single answer.

 

[Derrel]

My preference on 24-megapixel Nikon is generally to crop at the computer. On APS-C, which I used from 2001 to 2006, was to use a tele-converter. At that time, I had APS-C cameras of 2.7 MP, 6MP, 8.2 MP, and then 12.2 MP, and on APS-C both the lens and the converter were not "seeing" the weakest part of the lens or converter: the edges of the lens's field and the edges of the converter's field.

Tele-converters are ALWAYS a bit of a compromise. Some tele-converters are well-matched to specific lenses, some are average, some are very poor matches to specific lenses. The old so-called "matched converters" which were actually designed to be used with a specific lens, made their appearance in the mid-1970's for zoom lenses, and Nikon made some converters that worked very well with specific long tele lenses, beginning at 300mm, with the TC-300 and TC-301 models for lenses 300mm and longer, and later had the AF-i converters which were designed for the then small handful of super-tele, AF-i focusing, big glass lenses (which was a VERY small group of high-grade lenses). Today, Canon has really awesome converters for their new 70-200 Mk 11 f/2.8 zoom, and today, Nikon has $500 converters with aspherical element designs, and which work pretty well on their big glass lenses and the 70-200 mark two.

The way it works is this: each person needs to decide if a particular converter paired with a particular lens is good enough for specific uses. A really good wildlife blogger went through the various Nikon AF converters he has, with specific Nikon lenses like 200/2 VR, 300/2.8 VR, 400/2.8, and so on. For some uses, he was satisfied that the TC unit was acceptable. Birding often has a bird in the central area of a frame, with an indistinct sky or water background, and many good bird shots have been made with a long lens and a TC. Long-distance landscape work might not look nearly so good if the corners show bad image quality. As 480sparky said, "It depends".

But simply, consider this: a converter brings with it optical lowering of image quality. If the main lens is a good lens, and you have a high-megapixel image, it ought to crop reasonably well and still hold up. Now that most people have 20 MP, I think converters make less sense than they did back in the 2.7 to 8 MP era.

 

[Peeb73 2]

I often ask this question to myself.

 

[Solarflare]

Thom Hogan wrote a bit about that and IIRC his overall conclusion was "1.4x converters have hardly any loss of IQ, but 2.0x have an substantial amount of loss".

Since I never handled a converter myself, thats all I know.

 

[Didereaux]

Consider this: George Lepp, Art Morris, Tom Manglesen, and several other TOP nature photographers ALL use tele-converters, some stack them. I think I would follow their lead over any advice given on photo forums.

 

[Peeb73 2]

Consider this: George Lepp, Art Morris, Tom Manglesen, and several other TOP nature photographers ALL use tele-converters, some stack them. I think I would would follow their lead over any advice given on photo forums.

I think how and why they use them would be worth discussing on a photo forum, wouldn't it?

 

[Didereaux]

Consider this: George Lepp, Art Morris, Tom Manglesen, and several other TOP nature photographers ALL use tele-converters, some stack them. I think I would would follow their lead over any advice given on photo forums.

I think how and why they use them would be worth discussing on a photo forum, wouldn't it?

Yes. But I think a google of them will let the viewers read the reasons in their own words without someone paraphrasing, and missing something. Don't you?

Also try BH Youtube channel for Art Morris, and creative Live for Tom Manglesen and George Lepp, as well as their blogs and web sites.

 

[SCraig]

As others have said, "It Depends". It depends on the quality of the teleconverter, on the quality of the lens, and the quality of the camera, and sometimes, just on the exposure itself. I've tried it myself on several occasions. MOST of the time just cropping the photograph resulted in a better final image. SOMETIMES the TC shot resulted in a better final image. As a general rule I quit using my teleconverter and just crop what I get.

 

[spiralout462]

My goal is to get as much information as I can on the sensor. More info=more detail. I wanna fill half the frame, sometimes that requires a TC.

 

[FotosbyMike]

Here is some food for thought on TC:
Teleconverters do a lot more than magnify the image though:

1. The teleconverter reduces the maximum aperture of the lens by one stop (1.4x converter), 1.5 stops (1.7x converter) or 2 stops (2x converter). An f/4 lens becomes an f/5.6 lens with a 1.4x mounted. An f/5.6 lens becomes f/8.
2. Since most cameras lose the ability to autofocus at f/8, an f/5.6 lens with a 1.4x converter mounted won’t autofocus on most camera bodies.
3. Teleconverters add an extra set of elements to the light path after the lens has done its job focusing the image refracting the image one more time. This will degrade image quality either a little bit or a lot depending on the lens and converter being used.
4. Teleconverters add an extra set of electrical contacts between the camera and the lens. In the case of some third party converters electrical information may not be passed from the camera to the lens (this can be a good thing as well as a bad thing as we’ll discuss later).

You can read more here Teleconverters 101

 

[robbins.photo]

Hey folks, question about long telephoto work. Is it better to use a teleconverter or crop your photo down? With a teleconverter, you could get the framing right, but at the cost of speed and noise (any other cons?). Without it, you would have a probably better quality photo, but would then need to crop down. Which would you rather do, and why?

If you need an example, just go with a 400mm f/4, either using a teleconverter or cropping down.

It's very situational actually. I use a Sigma 70-200 mm F/2.8 and I have two TC's, a sigma 1.4x and a sigma 2.0x.

Both work rather well, not a lot of noticeable loss of IQ when using the TC. I think this might be due in part to the fact that it's a sigma TC being used with a Sigma lens, and in part due to the fact that I'm shooting this on an APS-C sensor camera as opposed to a full frame.

I do use the TC for extra reach when I'm out shooting say BIF shots or stuff that I will probably need to crop even after I add in the TC. When I'm closer in and can crop the picture without using the TC, I'll normally go that route.

Really your best bet is to shoot yoruself with both the TC and without and get a feel for what works best given your combination of lens, camera body, TC and distance from subject. There really isn't a hard fast answer here I'm afraid.

 

[gckless]

Thanks for the info everyone. I realize there are some things out there, just wanted to get a couple more opinions and experiences, which has proven fruitful. I don't have the cash to throw around to just get both to try out, so I like to do more research before getting something. Next rental period I may give a TC a shot, along with a lens. Been wanting to try both a Nikon 80-400mm VR and a Sigma 150-600mm sports and see which I like, but that's outside this discussion
I'll try a Nikon TC with my 70-300mm that I know well and see what happens.

 

[JacaRanda]

Consider this: George Lepp, Art Morris, Tom Manglesen, and several other TOP nature photographers ALL use tele-converters, some stack them. I think I would would follow their lead over any advice given on photo forums.

I think how and why they use them would be worth discussing on a photo forum, wouldn't it?

Yup and without being snarky . It helps when the lenses you are putting the tc's on are in the $10,000.00 range.

 

[robbins.photo]

Thanks for the info everyone. I realize there are some things out there, just wanted to get a couple more opinions and experiences, which has proven fruitful. I don't have the cash to throw around to just get both to try out, so I like to do more research before getting something. Next rental period I may give a TC a shot, along with a lens. Been wanting to try both a Nikon 80-400mm VR and a Sigma 150-600mm sports and see which I like, but that's outside this discussion
I'll try a Nikon TC with my 70-300mm that I know well and see what happens.

Most likely what will happen is you'll be terribly disappointed and your autofocus won't work. Teleconverters actually reduce the amount of light coming into the camera so they can't really be used effectively on slower lenses like a 70-300mm 4.5-5.6.

To use a TC you really need a faster lens, like an F/2.8 or F/4 - otherwise especially with a 2x TC you lose 2 fstops putting you at or above F/8, and your camera will either have a very difficult time autofocusing or will not be able to at all.