Focal lenght comparison with Teleconverter

Scootatheschool1990 · 05-01-2013, 09:45 PM

I wanted to see the difference between all of my lenses in terms of focal length. This is what I thought would best represent them all in one photo. The number stands for the focal length, eg: 14=14mm. The "t" after the focal length means it was taken with my Tamron 1.4 x AF TC (autofocus Teleconverter).
Lenses:

SMC Pentax DA 14mm f/2.8 (35mm eq. =21mm)
14mm w/ 1.4 TC =19.6 (35mm eq. =29.4)

SMC Pentax DA* 55mm f/1.4 (35mm eq. =82mm)
55mm w/ 1.4 TC =77 (35mm eq. =115.5)

SMC Pentax Da* 60-250mm f/4 (35mm eq. =90-375)
60mm w/ 1.4 TC = 84mm (35mm eq. =126mm)
250mm w/1.4 TC= 350 (35mm eq. = 525mm)

**Lowell Goudge** · 05-02-2013, 04:16 AM

this needs to be moved to the lens discussion forum, it does not belong here

Scootatheschool1990 · 05-02-2013, 06:41 AM

Originally posted by Lowell Goudge

this needs to be moved to the lens discussion forum, it does not belong here

How do I get it over there?

**Lowell Goudge** · 05-02-2013, 06:53 AM

ask a moderator to move it for you.

some times, actually many times they will see the post and move it but it never hurts to ask

in the pull down menu under forum there is a contact a moderator tab
I have never tried it myself

Fogel70 · 05-04-2013, 07:55 AM

There seems to be way too small difference between 14 and 14t frames.

Scootatheschool1990 · 05-06-2013, 10:24 PM

Do you think so? It's what matched up. I took each photo at a transparency to 50% and fit each photo into the previous. Matching up every feature. But I'm with you. I thought it would be less field of view

Fogel70 · 05-06-2013, 11:15 PM

The TC should give you the same amount of crop on all focal length, but 14mm with 1.4x TC seems to be less than 15mm, not 20mm it should be.

Scootatheschool1990 · 05-10-2013, 12:56 PM

Yeah let me try it a second time.

05-01-2013, 09:45 PM	#1
Scootatheschool1990 Veteran Member Join Date: Jun 2012 Location: Boise Idaho Photos: Gallery \| Albums Posts: 466	Focal lenght comparison with Teleconverter I wanted to see the difference between all of my lenses in terms of focal length. This is what I thought would best represent them all in one photo. The number stands for the focal length, eg: 14=14mm. The "t" after the focal length means it was taken with my Tamron 1.4 x AF TC (autofocus Teleconverter). Lenses: SMC Pentax DA 14mm f/2.8 (35mm eq. =21mm) 14mm w/ 1.4 TC =19.6 (35mm eq. =29.4) SMC Pentax DA* 55mm f/1.4 (35mm eq. =82mm) 55mm w/ 1.4 TC =77 (35mm eq. =115.5) SMC Pentax Da* 60-250mm f/4 (35mm eq. =90-375) 60mm w/ 1.4 TC = 84mm (35mm eq. =126mm) 250mm w/1.4 TC= 350 (35mm eq. = 525mm)

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05-02-2013, 04:16 AM	#2
Lowell Goudge Site Supporter Join Date: Jan 2007 Location: Toronto Photos: Gallery \| Albums Posts: 17,888	this needs to be moved to the lens discussion forum, it does not belong here

05-02-2013, 06:41 AM	#3
Scootatheschool1990 Veteran Member Join Date: Jun 2012 Location: Boise Idaho Photos: Gallery \| Albums Posts: 466 Original Poster	Originally posted by Lowell Goudge this needs to be moved to the lens discussion forum, it does not belong here How do I get it over there?

05-02-2013, 06:53 AM	#4
Lowell Goudge Site Supporter Join Date: Jan 2007 Location: Toronto Photos: Gallery \| Albums Posts: 17,888	ask a moderator to move it for you. some times, actually many times they will see the post and move it but it never hurts to ask in the pull down menu under forum there is a contact a moderator tab I have never tried it myself

05-04-2013, 07:55 AM	#5
Fogel70 Pentaxian Join Date: Sep 2009 Location: Stockholm, Sweden Photos: Albums Posts: 3,062	There seems to be way too small difference between 14 and 14t frames.

05-06-2013, 10:24 PM	#6
Scootatheschool1990 Veteran Member Join Date: Jun 2012 Location: Boise Idaho Photos: Gallery \| Albums Posts: 466 Original Poster	Do you think so? It's what matched up. I took each photo at a transparency to 50% and fit each photo into the previous. Matching up every feature. But I'm with you. I thought it would be less field of view

05-06-2013, 11:15 PM	#7
Fogel70 Pentaxian Join Date: Sep 2009 Location: Stockholm, Sweden Photos: Albums Posts: 3,062	The TC should give you the same amount of crop on all focal length, but 14mm with 1.4x TC seems to be less than 15mm, not 20mm it should be.

05-10-2013, 12:56 PM	#8
Scootatheschool1990 Veteran Member Join Date: Jun 2012 Location: Boise Idaho Photos: Gallery \| Albums Posts: 466 Original Poster	Yeah let me try it a second time.