Lens Gurus: Why doesn't anyone make TCs for prime lenses under 100mm (Nikon fit)?

Naboo32

Naboo32

Messages
3,278
Name
Andy
Edit My Images
Yes
I've never actually used a teleconvertor, so their exact design and construction is still something of a mystery to me :shrug:. However, I understand the potential benefits of using one and was thinking that I would like to put a 1.4 x TC between my Nikon D700 and my Sigma DG HSM 50mm f/1.4 prime lens, to create "the ultimate portrait lens" :naughty:.

So, imagine my disappointment when I discovered that neither Sigma, nor Nikon, appear to make one which will fit :(.

I'm sure that there's a very simple explanation as to why this is and was hoping that one of you could enlighten me, please :). Is it due to the rear element protruding too far out the back of the lens, or is it just due to lack of demand for them on shorter focal lengths :shrug:?

Thanks in advance for your input :thumbs:.
 
I wonder if the Kenko 1.4x will fit?

I could try this combo.. usually though Kenko and Sigma HSM doesn't play well.

A modified Nikon TC 1.4E will certainly work too (as long as its possible to mount without collision)

I've got a feeling it might knock out AF due to uncorrected spherical aberations anyhow.. might give it a go tomorrow..!
 
puddleduck said:
I wonder if the Kenko 1.4x will fit?

I could try this combo.. usually though Kenko and Sigma HSM doesn't play well.

A modified Nikon TC 1.4E will certainly work too (as long as its possible to mount without collision)

I've got a feeling it might knock out AF due to uncorrected spherical aberations anyhow.. might give it a go tomorrow..!
Click to expand...


Andy, if you could do that, I'd be seriously grateful :). Much as I love the IQ from my big Sigma 50, I never shoot with it at f/1.4 anyway (too much CA :( ... when pixel peeping :D) and I often wish that I could get a little further "back from the action" when trying to do candid portraits. So, a 1.4x (or maybe even a 1.7x :thinking:) TC would really allow me to do a lot more with that particular lens than I can do right now.

I think that using it at, say, f/1.8-2 for a super shallow DOF would work well, if the subject was just far enough away to allow you to get their whole face in focus, whilst manitaining the creamy bokeh that I bought that lens for in the first place :naughty:.

Again, thanks for the offer. Look forward to hearing the results.
 
Well.. it fits :)



DSC00496-web.jpg


​

Need to figure out what the rear element is going to do when focusing.. but so far.. well I've got a TC on it :)
 
OK.. I've tried this combo and it does AF, albeit with a bit of jitter.

The TC doesn't report EXIF correctly.. but this was with the 50mm wide open with the TC, so I make it 75mm f/2.0



DSC_0726-sigmatest.jpg



​

I can probably do better in decent light, but the combo does work, although is a bit "glowy" (uncorrected spherical aberations)

Not sure it's going to be a good combo!
 
If you're prepared to manually focus, and also interested in macro, look out for the Vivitar 2x macro teleconverter. It's not just for macro!
 
puddleduck said:
OK.. I've tried this combo and it does AF, albeit with a bit of jitter.

The TC doesn't report EXIF correctly.. but this was with the 50mm wide open with the TC, so I make it 75mm f/2.0



DSC_0726-sigmatest.jpg



​

I can probably do better in decent light, but the combo does work, although is a bit "glowy" (uncorrected spherical aberations)

Not sure it's going to be a good combo!
Click to expand...

Andy, you're a superstar :thumbs:! I think that you may have just saved me 200 quid and so I owe you a pint (unless you're a whiskey drinker :suspect:) :D.

I was, perhaps naively, expecting much better IQ from that combo, although as you rightly say, it would look better in optimum lighting conditions. I don't like the sound of "jittery AF" either, although that too would certainly be better with more light and contrast :|.

So, thanks very much for taking the time to help me out (not for the first time, I might add :naughty:). I think that I will just keep the Sigma as it is and use it for what it does best (whatever that may be :D) and go back to using my Tamron 28-75mm f/2.8 for candid portraits.

That also means that I can use this month's "equipment budget" to spring for a new Nikkor 55-200mm VR for my D40. I need a "holiday lens" for it and this one really fits the bill :thumbs:.

Thanks also to everyone else who has posted here - I really appreciate the swift respsonses.
 
Yeah, I don't think I would be tempted to use this combo, although I enjoyed trying it out just to see :)

Actually the rear element recesses into the lens when focused at MFD (as per the shot) but when moving towards infinity the rear element moves out and I fear a collision.

FYI the "special" Nikkor TC-14E is not mountable at all.
 
put the money towards an 85mm lens I'd say.

EDIT - the other thing is you can always just crop the image PP, which would give you 6MP at 1.4x (70mm F2)
 
puddleduck said:
Yeah, I don't think I would be tempted to use this combo, although I enjoyed trying it out just to see :)

Actually the rear element recesses into the lens when focused at MFD (as per the shot) but when moving towards infinity the rear element moves out and I fear a collision.

FYI the "special" Nikkor TC-14E is not mountable at all.
Click to expand...

Yeah, I was a bit worried that you might have "a collision" on my account :(, whilst testing it (although maybe I wasn't crediting you with as much sense as I should have been :D - sorry)!

Still, it's good to know that the Nikkor version won't mount at all, too.

Ultimatley, I want to get my hands on a Nikkor 70-200mm f/2.8 VR and use a TC with that. In the meantime, I was just curious to know if I could buy the TC now and use it on other lenses (the Sigma being the prime candidate). It seems not :naughty:!

pearce_jj said:
put the money towards an 85mm lens I'd say.

EDIT - the other thing is you can always just crop the image PP, which would give you 6MP at 1.4x (70mm F2)
Click to expand...

Hi JJ!

Actually, the money's already gone now (on a 55-200mm VR DX for my D40), but as I said earlier, I can easily use my Tamron 28-75mm for this stuff and just be content with the f/2.8 aperture.

Alternatively, as you pointed out, I could just crop heavily (which is what I do with most of the images taken with that lens anway :shrug:).

Cheers for your input :thumbs:.
 
You must log in or register to reply here.
Back
Top