Do tele-converters increase magnification?

bertwert · 03-27-2016, 01:41 PM

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?

Adam · 03-27-2016, 01:46 PM

I think you've got it right

LensBeginner · 03-27-2016, 02:02 PM

Only "exception" are TC with an helicoid, obviously, but what increases magnification is naturally the "extension-tube" part.

bertwert · 03-27-2016, 03:27 PM

Originally posted by LensBeginner

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?

**jatrax** · 03-27-2016, 04:04 PM

Originally posted by bertwert

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

bertwert · 03-27-2016, 04:06 PM

Originally posted by jatrax

Sort of. Like this: 2x Macro Focusing Teleconverter: Vivitar, KAX, Telemore...et al Lens Reviews - Miscellaneous Lenses - Pentax Lens Review Database

Interesting...

**jatrax** · 03-27-2016, 04:13 PM

Originally posted by bertwert

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.

bertwert · 03-27-2016, 04:17 PM

Originally posted by jatrax

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.

MikeD · 03-27-2016, 08:01 PM

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.

LensBeginner · 03-28-2016, 12:18 AM

Originally posted by bertwert

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

**csa** · 03-28-2016, 06:50 AM

You certainly are getting great results with that TC!

bertwert · 03-28-2016, 06:50 AM

Originally posted by LensBeginner

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

Actually I don't...

**jatrax** · 03-28-2016, 08:57 AM

Originally posted by bertwert

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

normhead · 03-28-2016, 09:09 AM

Originally posted by jatrax

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.

bertwert · 03-28-2016, 12:42 PM

Originally posted by jatrax

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.

03-27-2016, 01:41 PM	#1
bertwert Veteran Member Join Date: Jun 2015 Location: Golden, BC Posts: 15,173	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
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,595	I think you've got it right Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

03-27-2016, 08:01 PM	#9
MikeD Veteran Member Join Date: Dec 2007 Location: traverse city MI Posts: 346	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

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03-27-2016, 02:02 PM	#3
LensBeginner Veteran Member Join Date: Sep 2014 Photos: Albums Posts: 4,696	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
bertwert Veteran Member Join Date: Jun 2015 Location: Golden, BC Posts: 15,173 Original Poster	Originally posted by LensBeginner 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
jatrax Site Supporter Join Date: May 2010 Location: Washington Cascades Photos: Gallery \| Albums Posts: 12,991	Originally posted by bertwert 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
bertwert Veteran Member Join Date: Jun 2015 Location: Golden, BC Posts: 15,173 Original Poster	Originally posted by jatrax 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
jatrax Site Supporter Join Date: May 2010 Location: Washington Cascades Photos: Gallery \| Albums Posts: 12,991	Originally posted by bertwert 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
bertwert Veteran Member Join Date: Jun 2015 Location: Golden, BC Posts: 15,173 Original Poster	Originally posted by jatrax 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.

03-28-2016, 12:18 AM	#10
LensBeginner Veteran Member Join Date: Sep 2014 Photos: Albums Posts: 4,696	Originally posted by bertwert 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
csa Loyal Site Supporter Join Date: Aug 2014 Location: Montana mountains Posts: 10,133	You certainly are getting great results with that TC!

03-28-2016, 06:50 AM	#12
bertwert Veteran Member Join Date: Jun 2015 Location: Golden, BC Posts: 15,173 Original Poster	Originally posted by LensBeginner 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
jatrax Site Supporter Join Date: May 2010 Location: Washington Cascades Photos: Gallery \| Albums Posts: 12,991	Originally posted by bertwert 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
normhead Pentaxian Join Date: Jun 2007 Location: Near Algonquin Park Photos: Gallery \| Albums Posts: 40,451	Originally posted by jatrax 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
bertwert Veteran Member Join Date: Jun 2015 Location: Golden, BC Posts: 15,173 Original Poster	Originally posted by jatrax 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.