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03-27-2016, 01:41 PM   #1
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Do tele-converters increase magnification?

When using a TC with lenses it doesn't decrease the minimum focus distance so it must increase the magnification?

Have I got this right:
Using a TC with a true macro, DFA 100/2.8 Macro for example, the lens would have a magnification of 1.4:1?
Using with a DA* 300/4 which has around 1:4 (0.24x) in the first place it would make the magnification 1:3 (0.336x) as 0.24 x 1.4 = 0.336.

So is this correct?

03-27-2016, 01:46 PM   #2
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I think you've got it right

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03-27-2016, 02:02 PM   #3
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Only "exception" are TC with an helicoid, obviously, but what increases magnification is naturally the "extension-tube" part.
03-27-2016, 03:27 PM   #4
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QuoteOriginally posted by LensBeginner Quote
Only "exception" are TC with an helicoid, obviously, but what increases magnification is naturally the "extension-tube" part.
Sorry what's that?

A TC with a built in extension tube?

03-27-2016, 04:04 PM   #5
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QuoteOriginally posted by bertwert Quote
A TC with a built in extension tube?
Sort of. Like this: 2x Macro Focusing Teleconverter: Vivitar, KAX, Telemore...et al Lens Reviews - Miscellaneous Lenses - Pentax Lens Review Database
03-27-2016, 04:06 PM   #6
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QuoteOriginally posted by jatrax Quote
Sort of. Like this: 2x Macro Focusing Teleconverter: Vivitar, KAX, Telemore...et al Lens Reviews - Miscellaneous Lenses - Pentax Lens Review Database
Interesting...
03-27-2016, 04:13 PM   #7
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QuoteOriginally posted by bertwert Quote
Interesting...
Optically not great, but fun to play with. There are several versions, some have 'A' contacts and pass through everything, some do not. Also the price is extremely variable, so if you are interested watch carefully. I think I paid about $50 for mine with the 'A' contacts.

03-27-2016, 04:17 PM   #8
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QuoteOriginally posted by jatrax Quote
Optically not great, but fun to play with. There are several versions, some have 'A' contacts and pass through everything, some do not. Also the price is extremely variable, so if you are interested watch carefully. I think I paid about $50 for mine with the 'A' contacts.
I wasn't really thinking of getting anything but those do look sorta fun....


The original question just popped into my head as I was sitting around bored.
03-27-2016, 08:01 PM   #9
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It works just like you say Bert. I have a Tamron 90mm and the new Pentax 1.4 tc the only drawback is you get less light with the same aperture and a shallower depth of field. But then you can use focus stacking and take a BUNCH of shots and put them together in PS. Sadly for me my old comp is just too geriatric to do focus stacking. So I have to wait for Apple to come out with a new MBPro.

Last edited by MikeD; 03-27-2016 at 08:02 PM. Reason: spelling error
03-28-2016, 12:18 AM   #10
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QuoteOriginally posted by bertwert Quote
Interesting...
I paid 15 Euros for mine at a flea market and bought it mainly because of the macro feature... mine has no contacts.
It's great fun and I prefer to use that rather than close-up filters or reversed lenses. I don't have any extension tubes.

As with all TCs, however, it greatly magnifies all the flaws of the lenses you use it with.
OTOH, you get great results if you use it with a good lens and at the aperture sweetspot (like the SMC-M 50/1.7 @f/5.6) or near that (for DoF).

You already have a dedicated macro lens, however, so I suppose you're already set for macro

teleconverter by Lens Beginner, su Flickr

At f/8 (f/16)
lactarius by Lens Beginner, su Flickr

At f/16 (f/32)
bug by Lens Beginner, su Flickr
03-28-2016, 06:50 AM   #11
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You certainly are getting great results with that TC!
03-28-2016, 06:50 AM   #12
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QuoteOriginally posted by LensBeginner Quote
You already have a dedicated macro lens, however, so I suppose you're already set for macro
Actually I don't...
03-28-2016, 08:57 AM   #13
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QuoteOriginally posted by bertwert Quote
Actually I don't...
Well there you go then!

A nice 50mm and one of these and we have you hooked on macro
Of course then you will need:
1) focusing rail
2) low angle tripod
3) ring flash
4) "real" macro lens
5) A longer "real" macro lens
6) Focus stacking software

And eventually you will start browsing ebay searching for a 200mm f/4 macro
03-28-2016, 09:09 AM   #14
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QuoteOriginally posted by jatrax Quote
Well there you go then!

A nice 50mm and one of these and we have you hooked on macro
Of course then you will need:
1) focusing rail
2) low angle tripod
3) ring flash
4) "real" macro lens
5) A longer "real" macro lens
6) Focus stacking software

And eventually you will start browsing ebay searching for a 200mm f/4 macro
And then you'll rob a bank to buy one, and then you'll do 5 to 10 in a federal institution.

They always leave out the last bit.
03-28-2016, 12:42 PM   #15
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QuoteOriginally posted by jatrax Quote
And eventually you will start browsing ebay searching for a 200mm f/4 macro
I actually did that in a dream last night, found a NIB FA* 200/4 Macro for $100 shipped...
Then I woke up.
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