2 x magnification telephoto lens

[MarilynneT]

I previously asked about moon pictures and what lens to use for good close ups with my Canon EOS 1300D. I had some excellent advice on settings which I will try when we get some clearer skies and the moon is more full. My hubby wanted to buy me a lens for my birthday so I got a 2 x magnification telephoto lens which fits both other lenses I have with my camera. I tried it out earlier but couldn't get it to focus on anything or it wouldn't take a picture. I feel disappointed that it won't work or I'm doing something wrong. Could it be something to do with the settings? Help please.

 

[ancient_mariner]

Hi Marilynne, does the teleconverter have electrical contacts or is it 'dumb'? It may be that the converter doesn't connect the camera body with the lens, so requires you to focus manually instead of using the camera AF. It's also possibly just faulty.

What make & model is the converter, and do you have a link to where it was bought from?

 

[snerkler]

I previously asked about moon pictures and what lens to use for good close ups with my Canon EOS 1300D. I had some excellent advice on settings which I will try when we get some clearer skies and the moon is more full. My hubby wanted to buy me a lens for my birthday so I got a 2 x magnification telephoto lens which fits both other lenses I have with my camera. I tried it out earlier but couldn't get it to focus on anything or it wouldn't take a picture. I feel disappointed that it won't work or I'm doing something wrong. Could it be something to do with the settings? Help please.

When you say 2x magnification lens do you mean a 2x tele converter? If so what lenses are you trying to use it on?

A 2x TC makes the aperture of the lens 2 stops smaller so on an f5.6 lens that would make it F11, a lot of cameras won’t work when the maximum aperture is smaller than f8.

 

[TimHughes]

Try focusing with “liveview” instead of through the viewfinder. Using liveview avoids the problem highlighted by @snerkler which I think is the most likely source of the problem.

 

[andrewc]

does this adaptor fit between the camera and lens, or on the end of the lens?

 

[Box Brownie]

does this adaptor fit between the camera and lens, or on the end of the lens?

Hi Marilynne

As Andrew says above....

Please can you provide some more details about what you purchased?

There is a lot of difference between a x2 teleconverter and a x2 magnification lens.

Also, when you refer to the "two lenses", are those the two in your profile?

 

[MarilynneT]

There are no electrical contacts. It just fits on to the end of the two lenses I already have: Canon EFS 18-55mm and a Canon Zoom EF 75-300mm. It doesn't give a name or model and I got it from Amazon.

 

[MarilynneT]

Your pictures are stunning Box Brownie.

 

[rob-nikon]

There are no electrical contacts. It just fits on to the end of the two lenses I already have: Canon EFS 18-55mm and a Canon Zoom EF 75-300mm. It doesn't give a name or model and I got it from Amazon.

I’ve not used these but I’ve personally steerEd clear of them as whilst they sound great, and are promoted in the sales pitch as being good, they will likely affect image quality and lens performance. It’s quite likely its taken the maximum aperture beyond the camera maximum operating limit hence it’s not focusing. The good thing it you should be able to return to Amazon due to ‘not working’.

 

[MarilynneT]

I do have a Fotga 420 - 800mm f8.3 -16 superphoto lens but I thought this new lens would be a good addition to my lenses. I will take your advice Rob and send it back to Amazon. It's no use keeping it if it doesn't work as well as the lenses I have now. Thanks to everyone for your help and advice.

 

[Box Brownie]

There are no electrical contacts. It just fits on to the end of the two lenses I already have: Canon EFS 18-55mm and a Canon Zoom EF 75-300mm. It doesn't give a name or model and I got it from Amazon.

Thanks for clarifying that.

I’ve not used these but I’ve personally steerEd clear of them as whilst they sound great, and are promoted in the sales pitch as being good, they will likely affect image quality and lens performance. It’s quite likely its taken the maximum aperture beyond the camera maximum operating limit hence it’s not focusing. The good thing it you should be able to return to Amazon due to ‘not working’.

I am with Rob on this.......sadly I think such add-on telephoto lenses trap the unwary

It has been a while since I used Canon so will let those who still use it to advise you as to options & alternatives.

It was great that your hubby wanted to treat you and support your hobby but I hope you can get a refund and 'start again' on your quest to improve your photography.

 

[Box Brownie]

Your pictures are stunning Box Brownie.

Thank you

You must have dug deep.....I don't post many images and I am pleased you enjoyed them.

 

[snerkler]

Try focusing with “liveview” instead of through the viewfinder. Using liveview avoids the problem highlighted by @snerkler which I think is the most likely source of the problem.

I never knew that

There are no electrical contacts. It just fits on to the end of the two lenses I already have: Canon EFS 18-55mm and a Canon Zoom EF 75-300mm. It doesn't give a name or model and I got it from Amazon.

As mentioned, that's the problem, if there's not electrical contacts then there's no way the AF system can communicate and so won't work, these type of adapters are for manually focussing only. Also, even with a 2 x TC with electrical contacts you will run into the issue I mentioned above, your lenses are both f5.6 at the long end and with the 2 x TC that will make it f11 in which case regular AF won't work. Looking at the specs on the Canon page the 1300D doesn't work beyond f5.6 and even then it appears to be centre point only which doesn't sound right to me as I'd have thought you can use all your focus points with the 18-55mm and 75-300mm?

You must have dug deep.....I don't post many images and I am pleased you enjoyed them.

Aren't they your photos linked in your signature?

 

[Box Brownie]

Your pictures are stunning Box Brownie.

Thank you

You must have dug deep.....I don't post many images and I am pleased you enjoyed them.

Aren't they your photos linked in your signature?

Doh! talk about my memory.........or lack of it

I had forgotten about my 'signature' TP does not show it on every post and AFAIK not at all on the mobile version

FWIW I have not added to my 500px gallery for ages. I really must get a grip and update it and other stuff! Including my next upcoming attendance at the exhibition in December

 

[sk66]

As mentioned, that's the problem, if there's not electrical contacts then there's no way the AF system can communicate and so won't work, these type of adapters are for manually focussing only.

Because this 2x diopter goes on the objective end of the lens it does not require electrical contacts for the camera to autofocus. It also does not reduce the effective aperture (f#) like a TC does; so it's not an f/8+ issue either.

I am quite certain it is just a quality issue. A decent TC/2x will cost around a few hundred and it will still cause some loss of image IQ; there's just no way those really inexpensive diopters can come remotely close to that... this is one of those cases where you primarily "get what you pay for."

 

[sk66]

BTW, I would also NOT recommend getting a more expensive TC (teleconverter) to use with your lenses. That would result in a smaller effective aperture and cause your camera to not be able to focus (w/ lenses at max FL). Plus IDT the IQ of the 75-300 would stand up to the additional magnification and degradation a TC introduces.

TC extenders are called "teleconverters" because they are a group of telephoto lens elements meant to convert faster standard lens designs (primes) into telephoto lens designs of longer focal length... they do not work nearly as well on lenses that are already telephoto designs (typical of slower long FL's and zoom lenses like your 75-300).

 

[Sangoma]

Also, with the -S lenses, the teleconverter won't fit (well most won't) as the rear element sticks out the back too far.

 

[snerkler]

Because this 2x diopter goes on the objective end of the lens it does not require electrical contacts for the camera to autofocus. It also does not reduce the effective aperture (f#) like a TC does; so it's not an f/8+ issue either.

I am quite certain it is just a quality issue. A decent TC/2x will cost around a few hundred and it will still cause some loss of image IQ; there's just no way those really inexpensive diopters can come remotely close to that... this is one of those cases where you primarily "get what you pay for."

Ahh sorry, I got the wrong end of the stick what the adapter was