Madhukr

I use canon 7d mark II and a canon 100 - 400 mm lens. Should I add a teleconverter to it. Please suggest.

rmalarz Loc: Tempe, Arizona

Personally, I tend to stay away from them. The primary reason is that they multiply, that's their job. However, they also multiply any flaws the lens used in conjunction with the converter might have. So, a 2x converter will multiply any defect in the lens by a factor of 2, as well.
--Bob

TriX Loc: Raleigh, NC

Suggest you try the search function for extenders or teleconverter - this subject is discussed weekly - it's been addressed on three different threads in the last week or so. There are a variety of opinions on the subject (as you will see), and it varies as to whether you use a zoom or prime, the manufacturer of the extender and whether you employ a 1.4 or 2.0. But to answer your question, it depends on the lens and the teleconverter. In your case, Canon has published MTF charts on the 100-400L MK2 with the Canon 1.4 extender, and the results show a very small degradation in IQ of roughly 5%, which I find very acceptable. You didn't mention which version of the 100-400 you have, but we have at least one member who uses the MK2 version with 1.4 and 2.0 Canon extenders and produces superb results. I use the 100-400L Mk1 with the 1.4 MK2 extender with excellent results, even when enlarged to 16x24. Here are the MTF charts for the 100-400L MK 2 with and without the 1.4 extender so that you can decide for yourself. (I've posted these charts 4 times in the last 2 weeks, so I'm sure some are tired of seeing them) Personally, I would not go to the 2.0x with the Mk1 version of the lens, but as I mentioned, others with the MK2 lens and mk3 2.0x extender have great results. Another consideration is whether your 7D MK2 will autofocus with the extender. I believe that the 7D2 will autofocus at f8, but not beyond, so you would have autofocus with the 1.4x, but not the 2.0x. Hope this helps a little.

VisualMusing Loc: Carrollton, TX

I use a 1.7x sparingly to get extend my 70-200 f2.8 for sports. I only use it if the light conditions are superb because that lens is only good to f4 with the TC.

I don't like shooting at high ISO, others don't mind, so to each their own as with all things in photography. Good luck.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

A 1.4X TC will take 1 stop of light and about 5% sharpness.

If you have a slow lens that isn't very sharp, or a zoom that isn't sharp at the max focal length, then it's not a good solution. Many cameras have a problem with focus when the max aperture is F8.

TCs are designed to be used with really sharp primes and zooms that are fast, where they will provide the maximum benefit with the least amount of negative impacts.

In general, I wouldn't put a TC on a 100-400, but if I had a 5DMkIV I might, and I'd have to test the combination on a 7D Mk II to see if it met my needs.

robertjerl Loc: Corona, California

I have and use three of them, Canon 1.4x III and Kenko Pro 300 1.4x & 2.0x. With my 100-400s (I have a mark I and a mark II) I use the Canon 1.4x III on my 7DII, works fine, IQ on the mark II is about the same as the mark I without converter and the mark I only loses about 5% or less, still very high IQ and I commonly print 13x19 from both lenses with the 1.4x. They do become f/8.0 so you are on center point focus with a bit of an assist from the 4 or 8 expansion points.

Several people here on the UHH use the 1.4x with their 100-400 and get excellent results.

jim quist Loc: Missouri

I have the canon 1.4 and 2.0 converters that I use on the 70-200. They work great. The 1.4 shoots a bit soft but is usually not noticeable. The 2.0 is softer.

Fotomacher Loc: Toronto

I went to Botswana in September and took (along with other glass) a 300mm f/4 and a TC17EII. Although, the max aperture bumps up to f/6.7 it was more than worthwhile to extend the reach to 500mm and since I shoot with a D810 and can crop the sensor in camera, extend all the way to 750mm. For me, a TC is a good tool to have in my bag.

CHG_CANON Loc: the Windy City

What most fail to recognize is the lens characteristics are not the same when using an extender.

Yes, there's more glass involved. Yes, there's a loss of light with a lessened maximum aperture. Yes, there is (or can be) a loss in responsiveness of the AF.

So, the photographer will understand these issues and compensate within the limitations of their equipment. One option is to fine-tune. But, I say the most important action is stepping down when using an extender. If you think your style only works wide open, then yes, and extender is not for you ...

The Flickr group at this link is focused on the Canon Extender 1.4III. You don't need to scroll further than the first page to find many fine examples of crisp, sharp images with this extender and a variety of Canon lenses and bodies. (Click an image to see the technical details.)

http://flic.kr/g/hAQCm

I've had similar success with the Nikon 1.7 model and Nikon's 70-200 f/2.8 VR. Third-party products are left to those who have experience with that equipment.

Leicaflex Loc: Cymru

I agree.

Pablo8 Loc: Nottingham UK.

The only one I use is a dedicated 1.4 extender for my 150mm f/2.8 Macro lens. It also emphasizes the good qualities of the prime lens.

Madhukr

Thanks for the great answer.

Madhukr

Thanks for the great answer

billnikon Loc: Pennsylvania/Ohio/Florida/Maui/Oregon/Vermont

I have three teleconverters and they are now collecting dust. I no longer use them. FOR A REASON. Learn to get as close as you can and learn good camera techniques, the results will be better than any converter will give you.

Architect1776 Loc: In my mind

If you have the MII version of the lens it has virtually no loss of quality with a MIII converter by Canon. This is not across the board with other lenses but this lens was designed to use converters by Canon and only a pixel peeper can tell any difference.