Should I go with a Sigma 150–600, or 70–200 + teleconverter?

Question

I am newer to photography and it is a hobby. I take photos at sports events for myself and friends. I currently have a Nikon Z 6II with a FTZ adapter, with 35mm and a 70–200mm lenses. I was looking at getting the Sigma 150–600 mm for getting a farther zoom at events so that I do not need to move around as much. But I have recently learned about teleconverters which I could use with my 70–200 mm.

I am unsure if it would be better to buy the lens or the teleconverter for my current lens. This is a new area for me in photography.

Edit: I am not really sure the difference that the extra 200 mm would make from the lens to a 2x teleconverter. As zoom distance it not something I have been able to find in feet/yards.

Answer 1

A teleconverter can increase your focal length, but it also reduces your exposure brightness and can reduce image quality/sharpness. You should also be aware that longer focal lengths will reduce your depth of field, making it shallower. As your 200mm becomes a 400mm, the DOF will be cut in half. To maintain a wider depth, you'd have to reduce your f-stop, but you'll already be at a loss of light by using a teleconverter. You could compensate by raising your ISO or reducing your speed, but you probably don't want to reduce speed for sports/frisbee golf.

Note: The "Nikon Z Teleconverter TC-2x" states that using it will result in 2 stops of light loss. According to B&H, it is compatible with the NIKKOR Z 70-200mm f/2.8 VR S.

Something to also keep in mind is that as you extend your focal distance, maintaining stability is going to be more difficult. Obviously the lens' 5-stops image stabilisation (assuming you are talking about this lens) and the z6ii's 5-stops of IBIS help. This is just to say that you may have to increase your speed to compensate for shake at a longer focal length, compared to what your minimum speed is now at 200mm. You can check what the stabilization rating is of the prospective Sigma lens.

As far as how effective it is on extending your zoom to a subject from the same distance, I like to review some images/videos from other photographers. Derrel Ho-Shing Photography has a youtube video that compares 200mm and 400mm for a full body shot. Wolf Amri has a different video that compares 200 and 400mm for a large building that is far away.

Actually, there are some videos comparing the use of the TC-2x and a longer lens. Definitely browse some and note the lighting conditions. Lens and gear comparison videos are a rich area on youtube.

Perhaps you could test the teleconverter by renting it from a place like BorrowLenses, LensRentals, LensProToGo, etc. I have done this a couple times with some gear.

Answer 2

These are not (reasonably) equal alternatives because you already have the 70-200/2.8. This is a very good lens, and it obviously is much more versatile than a 150-600. Presumably, you don't want to get rid of it. Then your alternatives are an extender vs quite a big and heavy lens.

Sigma 150-600 C is a very decent lens. It is also "only" twice as expensive as the (fundamentally very simple) Nikon teleconverter. But it's heavy! It won't fit in most normal photo backpacks or some photo bags without compromises. (But it comes with its own carry case). In contrast, you can always carry the extender with you.

If this is not an objection for you (say, you just bring a single specific set-up to an event), then you need to decide whether an extra 1.5x magnification is needed.

In the shared range 150-400 they will have very similar brightness (~f/5.6). I have both of these (but for Canon) and I'd say the image quality is reasonably similar as well. It's harder to comment on focusing and stabilisation as performance may be different (N vs C), but you shouldn't expect wonders from either. Long lenses are demanding and you'll need to learn to handle them anyway.

So, do you need 400-600 (for extra money and weight)? Hard to say without knowing your exact scenario. To answer it, renting either of these options to try is a good idea. If you get the 2x, see if you mostly shooting at the long end and then need to blow up more. If you get the 150-600 (which would be preferable so that you could assess its weight and size), see if you use 400+ a lot. Then decide. In other respects they are comparable, as I said.

P.S.

1. Sigma 150-600 has two versions: C[ontemporary] and S[port]. The latter is significantly more expensive and heavy. If you needed it, you would have known it.

2. Sigma zoom ring rotates the Canon way (opposite to yours). Depending on your attitude, such inconsistency may play a role in your decision.

3. Sigma's bokeh is not particularly pleasing (but not bad either; just "normal" for modern sharp lenses). I'm not sure how it compares to your Nikon's 70-200, but Canon's is certainly better (esp. early ones). This is probably a minor consideration though.

Answer 3

I think normally people need a methodology to decide what focal length they need. Because the only one that is on the field, literally, is you.

1. Focal length

As you already have a 200mm lens, you have the starting reference point.

Take one of the typical photos you like, taken at 200mm.

Then, to imagine how it would look at 400mm at the same photographer's position, just reframe it and crop it 200% or 2x, and now you have the 400mm framing.

For a 600mm do the same 3x.

This is not an exact real-life result, because construction and design of the lens, but will give you a good estimate.

2. Shutter speed, noise, and aperture

Then you have to determine the speed of the lens.

Determine the aperture and shutter speed of your photos. Do you like the blur? Do you expect less motion blur? Are you pushing too much the ISO to get that speed? Do you accept that level of noise? Can you push the ISO 1 step more?

An old "rule of thumb" is to have a shutter speed "equivalent" of the focal length to avoid hand-held camera shake. Although you most likely will use a tripod, it is an interesting starting point.

So, can your camera shoot at 1/400 s with a decent amount of noise, in your given light scenario? What aperture are you using? Do you need a faster shutter speed?

So now with the info you have, you can determine if a 2x teleconverter is suitable for you. or a specific lens with specific apertures.

3. Sharpness and pricing

For that extra sharpness, do you want to pay the extra $$? Can you live with less sharp images? Can they be improved using software?

Are you really using the full file for a large print? Or are you only using the files for social media, and then some cropping is enough?

4. Extra considerations

Do you need an extra bag? Is the combo portable enough? Will you be using more a 150-600 and leaving the other at home?

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Do these tests, make notes and you will learn a lot more than you expect!

Answer 4

I started photographing Ultimate Frisbee in the 80's with a 70-200mm zoom using a monopod rather than a tripod and was fairly successful capturing moments of peak action and getting them published. The main things that enabled that were my playing experience with the ability to anticipate where the action was going on the field and the knowledge of the proper settings for freezing the action. This meant highest shutter speeds and setting the aperture to provide some depth of field when enough light was available.

Now with digital sensors, increasing the ISO can make it easier to get the shutter speed & aperture settings just right for capturing the action.

I moved up to longer prime lenses rather than using teleconverters as my experience increased and improved and I came to understand that TC's are a factor that can decrease action image quality.

I now shoot AUDL, PUL & Club Tournaments with a Sigma 150-600mm Sport on my primary camera body, a Nikon D850 mounted on a gimbal head on a monopod and a 70-300 on a D600 as secondary body hand held for when the action gets close.

If your budget allows it, I'd go with the big lens then get a 2nd body if your interest grows like mine did!

You can see a lot of my shared Ultimate and other Frisbee photos if you look me up on Flickr and FB.

Hope this is helpful.