Teleconverters, are they worth it?

Hi all,

I know I am a bit spotty on here, forgive me for that. I come bearing more questions though, I hope I can get some answers better than what I could find on my own.

I am certainly in no position to buy a better telephoto lens, I have restocked on new bulk film (flick film ultrapan 400, for those who are interested) and am in a position where I could be able to enter a photo contest with a magazine, the problem is that its a wildlife magazine and I only have a 75-300mm lens for distance work. I was looking into renting a lens when I discovered teleconverters. I did some reading and I know they mess with my light and my quality but I figured I am shooting midday-ish so if I use a fast film I might just be fine. but I also know that comparability and image quality are big things I have to keep in mind.

So here is my thought: " if I can find a decent priced teleconverter compatible with my lens and my body I might be able to get a clear enough image in order to compete", but I don't know which companies produce good stuff. I also don't know if its better to just rent a better lens. I have my shooting location scouted out and I know my animal (a coyote) frequents that area so its just a matter of getting a good clear shot. does anyone have any advice on which is better for an amateur who just wants to start?

Thanks for your patience and advice.

P.S. I tried the proverbial "zoom with your feet" method and I lose my cover and I worry it will scare off the subject if I am closer.

Go for a fixed mm telephoto lens.

They are fine devices so long as they are built well. With no camera system mentioned that is as far as I can go.

But assuming what you have is one of the major brands, get the one from same. They add quite a bit versatility in a rather small package.

If you will be running test charts with it, then it might not be a winner. But for making images they give enough return on the investment. Some makes are quite good actually, but they may not be a much cheaper alternative to a longer lens. However, they will increase reach of what you have in a smaller, more manageable package.

Homebrewmess said:

I only have a 75-300mm lens for distance work

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That'll typically be something like f/4-f/5.6. With a 1.4 TC this will become f/8 on the long end, a 2x TC will make it f/11. Both manual focus microprisms and AF systems on most film cameras will be virtually unusable in such a setup. The optical quality of your extended 450-600mm lens will be poor. You will only be able to shoot fast film in good light since you need high shutter speeds to prevent motion blur.

All in all, it's a pretty frustrating situation to begin with. I wouldn't bother personally.

Plus one for what has been said. My guess for a magazine entry it will be online at a specific size so resolution may not be too much of an issue but rather judged on content. If that is the case owning it may be more practical than renting since the cost may be the same. If it’s a 2x it’s a two stop adjustment for you which could be a factor.
I have a Hasselblad Mutar 2x that I have used with their 250 and 350 with very good results.

One important thing to remember, quality converters were built to a specific lens and always for single focal length, so optics were matched as best as possible to that particular lens design. Then there are converters for a focal range they will work with relatively well.

Converter is an optical compromise in itself, with exception of single lens dedication. The more "universally" it is to be applied, the more result variation depending on what lens it was used with.

@koraks is of course right bringing on the issue of lens aperture changing substantially by converter's factor. And lens you mentioned is indeed likely a dark one to start with.

But without details on your system there is no way to go beyond this point.

There's no really good reason NOT to buy a tele-converter -- except for the really, ridiculously priced ones. Some can cost as much as a long, fixed focal length lens.

If you get a tele-converter today, and you buy a longer lens tomorrow, you can still use the tele-converter on the new lens.

But, there are many things to keep in mind. Some of these have been mentioned.

First, you need to decide on the strength of your tele-converter -- 1.4X, 2X, 3X?

Whatever strength, your viewfinder will be darker -- and if it's an AF tele-converter, there's a good chance that you will have to use manual focusing.

Since the focal length will be longer, and the exposure needs to be increased, there's also a very good chance that you will need to use a tripod.

Add in that you'll only get good results if you stop-down the lens, a tripod should be on your list -- but that's true if you simply bought a longer lens.

The results will depend on how you use the tele-converter, but also on the prime lens. If it's a great prime lens, you'll get better results than with an inexpensive lens or a zoom.

We could give you better feedback if we knew exactly what gear you have now.

Ideally choose a tele-converter dedicated to the specific lens you have in mind. Generic substitutes can be disappointing. But either way, you'll have a lot of light loss, and probably some sharpness loss too, or at least difficulty focussing. Other than portability, they're generally a poor substitute for a longer tele to begin with.

Don't forget - "wildlife" can include the very small and very close.
A recent international winner - not me - that was featured in local media: https://www.nhm.ac.uk/wpy/gallery/2025-like-an-eel-out-of-water?tags=ed.current

Here are two that I took to test the 2x and a support I had made by a machine shop to balance the camera , lens and 2x so the weight was even over a sturdy tripod.
the subject of the scenic was more than a mile away over the water. It is an old 350 that I bought at least twenty yrars ago (it was old then but the price was right an it was in like new condition).

A good and fast lens like the Nikon 300mm f/2.8 would do well with Nikon 1.4x and 2x teleconverter.

MattKing said:

Don't forget - "wildlife" can include the very small and very close.

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Another good advantage of a tele-converter is that the close-focusing point remains the same, so it seems that you get closer due to the higher magnification.

I've seen some old movies with ants and cockroaches as big as buses, terrorizing small towns and eating people. I guess that would be a good candidate for magnified "wildlife" photography. Or maybe just play the mad scientist, and actually grow bugs that big.

When a working PJ in the 80s I carried a Vivitar 2X macro converter that in an emergency I could use with a Nikon 200 F4. It never came that. I did test it, there was some loss of resolution and distortion, so in the end maybe just cropping in would have as effective. I have a 1.4 Minolta that is matched to the Minolta A mount AF 300 2.8 lens, although some of speed it remains sharp with very little distortion. When used a Sigma 400 5.6, horrible. What lens are your using?

Homebrewmess said:

if I can find a decent priced teleconverter

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My sole teleconverter makes a good paperweight.

If you're going to spend money, I'd honestly suggest putting the money towards a lens.
There is no magic unfortunately.

Homebrewmess said:

P.S. I tried the proverbial "zoom with your feet" method and I lose my cover and I worry it will scare off the subject if I am closer.

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I would be finding the best subject that will work with the gear you have available.

Again, we don’t know what camera or lens you are using, but if it’s 35mm I have some ideas. Many years ago I needed a long tele for motor racing shots. I had little money. I bought one of those cheap 400mm preset (no auto diaphragm) lenses from Spiratone (I just checked on eBay, they go for $20!). It worked surprisingly well, I still have it and the T mounts to use it on my Olympus or my M42 screw mount Pentax. There are 600mm ones out there too.

The Pentacon Six Carl Zeiss Jena Sonnar 180mm f/2.8 works very well with the 2X teleconverter, because it is extremely sharp to begin with. You must stop down twice for best use which gives you an effective aperture of f/11.

The Canon FD 300mm f/4 L lens works well, because it is quite sharp, but not as sharp as the previous mentioned lens, so you do see a slightly softer image when you use the teleconverter. It's best to stop down once which again gives you an effective f/11 aperture.

Lenses which have only slightly above average or lower sharpness, or lenses that peak in sharpness above f/5.6 without the converter - you generally shouldn't bother with.

It also matters where the sharpness bottleneck is in your workflow. For example, if you are effectively 2400 dpi limited by an Epson flatbed scan, then you won't notice the lack of resolution of a teleconverter as quickly as someone who is 4800 dpi limited.

They're generally cheap, why don't you try it and sell it if you don't find it useful.

Paul Howell said:

in the end maybe just cropping in would have as effective.

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One of the BIG photo magazines did a comparison of this a long time ago. I'm sure this varies with the quality of the tele-converter, but their conclusion was a tele-converter, used correctly, was always better than a cropped image.

As if photo magazine articles can be trusted any more than web blurbs. It all depends on who wrote it,
and how valid their methodology either was or wasn't, and whether those old conclusions are still valid or not with respect to current choices.

If one wants longer lenses but can only afford a teleconverter, then go ahead and buy them with the knowledge that there will be loss of f/stops and some image softening. I have a Hasselblad 2X teleconverter to double my 500mm Hasselblad lens to 1000mm [1 meter] when I need the longer length. If you have to decide between two teleconverters of the same strength buy the one that has the better quality if possible.

gbroadbridge said:

I would be finding the best subject that will work with the gear you have available.

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This makes more sense honestly, I'll keep working within my gear in mind. thank you

Another consideration is space, weight, etc. There have been plenty of times when the gear I could bring was very limited -- like to one lens. Adding a longer lens was impossible, but a tele-converter was small enough to add.

The answer is, as with many things, it depends. I bought the Nikon TC-17II to go with my 70-200/F2.8 zoom, and it does an excellent job without compromising image quality too much or making the lens too slow.

If you're using a 75-300 lens, it's probably already pretty slow (F5.6?) at the long end. Attempting to use a teleconverter on that is pretty much a useless quest--it's probably not all that great optically to begin with, but the big problem is that it will become extremely slow. You'll likely have so much trouble focusing that you'll curse the idea of doing it.

Unless you're going to use it on something that's a constant F4 or faster, I would not at all recommend a teleconverter.

As you say it depends. I'm unlikely to use a tele-converter on a normal or wide-angle lens. The times I usually need it is where my tele lens is not long enough. Since all my long lenses are "slow" and I typically use a tripod, adding a tele-converter is not much of a problem. My 400mm f5.6 becomes an 800mm f11 -- which is just as usable as a Vivitar Series 1 800mm f11 Solid Cat. Not as small, but not as expensive, either.