Should I get a 2x converter for my Bigma?

[eeyore]

Originally Posted by RogerTheCat

I tried a sigma 2x convertor with my Sigma 150mm f2,8 macro and the images were very soft. I was very unimpressed with the convertor and got rid of it

i would suspect that this was more than likely caused by camera wobble rather than an inherent problem with the TC as you had effectively created a 2:1 macro and this degree of magnification is virtually impossible to use in the field -

I have acheived pin sharp shots with my tamron 90mm plus a 2xtc but this is almost half the focal length of your set up and still required a rock solid tripod, a bean bag atop the lens, mirror lock up, and a remote release to guarantee that images arent soft.

[Oy]

Originally Posted by eeyore

i would suspect that this was more than likely caused by camera wobble rather than an inherent problem with the TC as you had effectively created a 2:1 macro and this degree of magnification is virtually impossible to use in the field -

Sorry - but nope.

Adding a TC to a macro lens does not increase the magnification - just the focal length. The Sigma 150mm 1:1 macro just becomes a 300mm 1:1 macro. Extension tubes will increase magnification but teleconverters do not.

I've tried both x2 and x1.4 on mine.

x2 = too soft for my liking

x1.4 = excellent

[nitsch]

Originally Posted by Oy

Sorry - but nope.

Adding a TC to a macro lens does not increase the magnification - just the focal length. The Sigma 150mm 1:1 macro just becomes a 300mm 1:1 macro. Extension tubes will increase magnification but teleconverters do not.

I've tried both x2 and x1.4 on mine.

x2 = too soft for my liking

x1.4 = excellent

Actually a TC will increase max magnification on a macro lens. Adding the TC does not increase the minimum focus distance so if you shoot at the minimum focus distance with the bare lens and get 1:1 magnification, shooting from the same distance with a 2x TC fitted will increase that to 2:1. If you don't believe me try taking some shots of the millimetre scale on a ruler and see what happens.

As has already been stated in this thread, if you find 2x TC's soft you have to blame the lens not the TC. On a top end supertele the 2x TC's work very well indeed as these are the lenses that they were designed to be used with.

[eeyore]

Originally Posted by nitsch

Actually a TC will increase max magnification on a macro lens. Adding the TC does not increase the minimum focus distance so if you shoot at the minimum focus distance with the bare lens and get 1:1 magnification, shooting from the same distance with a 2x TC fitted will increase that to 2:1. If you don't believe me try taking some shots of the millimetre scale on a ruler and see what happens.

As has already been stated in this thread, if you find 2x TC's soft you have to blame the lens not the TC. On a top end supertele the 2x TC's work very well indeed as these are the lenses that they were designed to be used with.

yep thats what I thought - I've just checked and Paul harcourt davies' books also agree with this interpretation.

that said some cheap 2xtcs are soft, due to poor quality glass and/or poor quality control in lense grinding, being used to keep the price down - but if you team a top end 2xtc with a top end f2.8 lens you get top end results

[nitsch]

Originally Posted by eeyore

that said some cheap 2xtcs are soft, due to poor quality glass and/or poor quality control in lense grinding, being used to keep the price down - but if you team a top end 2xtc with a top end f2.8 lens you get top end results

Great way to sum it all up!

[RogerTheCat]

Originally Posted by eeyore

i would suspect that this was more than likely caused by camera wobble rather than an inherent problem with the TC as you had effectively created a 2:1 macro and this degree of magnification is virtually impossible to use in the field -

I have acheived pin sharp shots with my tamron 90mm plus a 2xtc but this is almost half the focal length of your set up and still required a rock solid tripod, a bean bag atop the lens, mirror lock up, and a remote release to guarantee that images arent soft.

I tried it on a tripod and saw little improvement Anyway the extension tubes I swapped it for are great

[Pete W]

I have the Bigma and have tried it with converters with limited success. I would stick with just using the Bigma for what it is a Great 50-500..

I think the Converters are only viable on big prime lenses with either f2.8 or f4.. otherwise results are a bit hit or miss as i said before (just my opinion) Oh if money was not a problem :lol:

[CJB450]

Hi im new to DSLR photography and would like to buy a "Bigma" for my D80, i was all set to get one from Hong Kong (Digital Rev no vat & 3 year warranty) but then have seen some second hand ones on e bay here and in the US and didn't know if there is any difference between the non DG bigma's and the so called "new DG "ones? Plus anyone had any problems with Hong Kong lenses eg warranty work?
my local shop said non UK Sigma lenes may not be covered by Sigma's warranty here ? or is he just trying to get £200 more out of me for a UK lens after all they must be all made in the same factory?

[glsammy]

Originally Posted by CJB450

Hi im new to DSLR photography and would like to buy a "Bigma" for my D80, i was all set to get one from Hong Kong (Digital Rev no vat & 3 year warranty) but then have seen some second hand ones on e bay here and in the US and didn't know if there is any difference between the non DG bigma's and the so called "new DG "ones? Plus anyone had any problems with Hong Kong lenses eg warranty work?
my local shop said non UK Sigma lenes may not be covered by Sigma's warranty here ? or is he just trying to get £200 more out of me for a UK lens after all they must be all made in the same factory?

Can I suggest you read this thread from the beginning? If you do, your questions will be answered. Hint: look at my posts.

Whoops! it wasn't this thread I made the comments on! Sorry!

I'll repeat it here for you.

I bought a Sigma 50-500mm from digital rev, same deal as you from the sound of it. The lens was faulty. Sigma repaired it without any problems. All they needed was a copy of the invoice plus proof that the import duty was paid, which Digital Rev paid for me.
So you can forget any problems re warranty.