APS-C and FA 43 lens focal length

Driline · 03-08-2013, 08:38 PM

I'm looking at purchasing the FA 43 lens for my K5 camera and I know the focal length will really be 1.5 times that or 64.5. My question is I have a Pentax DA 18-135mm zoom lens. If I want to approximate the FOV on the zoom lens do I look at 43mm or about 65mm on the 18-135 lens? Hope I'm making sense here......

NickLarsson · 03-08-2013, 08:53 PM

Same as the FA, so 43mm.

VisualDarkness · 03-08-2013, 09:18 PM

Focal length is the same as it's a lens characteristic and has nothing to do with the camera. 43mm is 43mm no matter if you put it on a film camera or an aps-c or even looking through it with your eyes.

The difference between putting the lens on a cropped sensor is that you won't use the total field of view (wasted glass area) as the borders get cropped out. So the only difference between a full frame lens and a crop lens is that the full frame lens has the capability to project a bigger image but it doesn't matter if the sensor is too small to pick up the bigger field of view.

Driline · 03-08-2013, 09:31 PM

Originally posted by VisualDarkness

Focal length is the same as it's a lens characteristic and has nothing to do with the camera. 43mm is 43mm no matter if you put it on a film camera or an aps-c or even looking through it with your eyes.

The difference between putting the lens on a cropped sensor is that you won't use the total field of view (wasted glass area) as the borders get cropped out. So the only difference between a full frame lens and a crop lens is that the full frame lens has the capability to project a bigger image but it doesn't matter if the sensor is too small to pick up the bigger field of view.

Thank you for making sense. So a 43 is a 43 is a 43 whether its on a full frame or my K5

Driline · 03-08-2013, 09:33 PM

Then I will continue my quest to purchase the FA 43 and forgo the DA 35 Macro......

Franky2step · 03-08-2013, 10:06 PM

good luck with the search, you will love the 43Ltd, it's a favourite lens of mine.

stevebrot · 03-08-2013, 11:09 PM

Originally posted by Driline

Thank you for making sense. So a 43 is a 43 is a 43 whether its on a full frame or my K5

...or on a medium format or a 4x5 view camera or on a ...

The only difference is the field of view. (45mm is an extreme ultra-wide with 4x5.)

Steve

Allison · 03-09-2013, 08:45 AM

Good luck with the 43, I love mine. You can add the 35 Marco to the list of what to buy next.

tclausen · 03-09-2013, 09:12 AM

Originally posted by Driline

Then I will continue my quest to purchase the FA 43 and forgo the DA 35 Macro......

Ha ha ha ha - good one

The Limited (DA or otherwise) are simply just addictive. The only one I've been able to resist so far is the 70mm, but I honestly do not know how long that'll last (despite having the 77mm)

Dynamo · 03-09-2013, 09:32 AM

Originally posted by tclausen

Ha ha ha ha - good one

The Limited (DA or otherwise) are simply just addictive. The only one I've been able to resist so far is the 70mm, but I honestly do not know how long that'll last (despite having the 77mm)

same here.... I started with DA 35 macro..then FA 77 and DA15 then........may be next FA 31 or sigma 30

tclausen · 03-09-2013, 09:45 AM

Originally posted by Dynamo

same here.... I started with DA 35 macro..then FA 77 and DA15 then........may be next FA 31 or sigma 30

Funny, I started with the 77mm - and the 35mm macro was my latest ltd. acquisition

03-08-2013, 08:38 PM	#1
Driline Pentaxian Join Date: Dec 2012 Location: IOWA Where the Tall Corn Grows Photos: Gallery Posts: 3,697	APS-C and FA 43 lens focal length I'm looking at purchasing the FA 43 lens for my K5 camera and I know the focal length will really be 1.5 times that or 64.5. My question is I have a Pentax DA 18-135mm zoom lens. If I want to approximate the FOV on the zoom lens do I look at 43mm or about 65mm on the 18-135 lens? Hope I'm making sense here......

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03-08-2013, 08:53 PM	#2
NickLarsson Veteran Member Join Date: Feb 2012 Location: Paris, France Photos: Gallery \| Albums Posts: 1,390	Same as the FA, so 43mm.

03-08-2013, 09:18 PM	#3
VisualDarkness Veteran Member Join Date: Nov 2011 Location: Uppsala, Sweden Photos: Gallery Posts: 4,439	Focal length is the same as it's a lens characteristic and has nothing to do with the camera. 43mm is 43mm no matter if you put it on a film camera or an aps-c or even looking through it with your eyes. The difference between putting the lens on a cropped sensor is that you won't use the total field of view (wasted glass area) as the borders get cropped out. So the only difference between a full frame lens and a crop lens is that the full frame lens has the capability to project a bigger image but it doesn't matter if the sensor is too small to pick up the bigger field of view.

03-08-2013, 09:31 PM	#4
Driline Pentaxian Join Date: Dec 2012 Location: IOWA Where the Tall Corn Grows Photos: Gallery Posts: 3,697 Original Poster	Originally posted by VisualDarkness Focal length is the same as it's a lens characteristic and has nothing to do with the camera. 43mm is 43mm no matter if you put it on a film camera or an aps-c or even looking through it with your eyes. The difference between putting the lens on a cropped sensor is that you won't use the total field of view (wasted glass area) as the borders get cropped out. So the only difference between a full frame lens and a crop lens is that the full frame lens has the capability to project a bigger image but it doesn't matter if the sensor is too small to pick up the bigger field of view. Thank you for making sense. So a 43 is a 43 is a 43 whether its on a full frame or my K5

03-08-2013, 09:33 PM	#5
Driline Pentaxian Join Date: Dec 2012 Location: IOWA Where the Tall Corn Grows Photos: Gallery Posts: 3,697 Original Poster	Then I will continue my quest to purchase the FA 43 and forgo the DA 35 Macro......

03-08-2013, 10:06 PM	#6
Franky2step Veteran Member Join Date: Aug 2011 Location: Niagara Photos: Gallery \| Albums Posts: 793	good luck with the search, you will love the 43Ltd, it's a favourite lens of mine.

03-08-2013, 11:09 PM	#7
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by Driline Thank you for making sense. So a 43 is a 43 is a 43 whether its on a full frame or my K5 ...or on a medium format or a 4x5 view camera or on a ... The only difference is the field of view. (45mm is an extreme ultra-wide with 4x5.) Steve

03-09-2013, 08:45 AM	#8
Allison Veteran Member Join Date: Apr 2008 Location: Pittsburgh, PA Photos: Gallery \| Albums Posts: 667	Good luck with the 43, I love mine. You can add the 35 Marco to the list of what to buy next.

03-09-2013, 09:12 AM	#9
tclausen Veteran Member Join Date: May 2012 Posts: 1,397	Originally posted by Driline Then I will continue my quest to purchase the FA 43 and forgo the DA 35 Macro...... Ha ha ha ha - good one The Limited (DA or otherwise) are simply just addictive. The only one I've been able to resist so far is the 70mm, but I honestly do not know how long that'll last (despite having the 77mm)

03-09-2013, 09:32 AM	#10
Dynamo Veteran Member Join Date: Dec 2012 Location: Groningen Photos: Gallery Posts: 311	Originally posted by tclausen Ha ha ha ha - good one The Limited (DA or otherwise) are simply just addictive. The only one I've been able to resist so far is the 70mm, but I honestly do not know how long that'll last (despite having the 77mm) same here.... I started with DA 35 macro..then FA 77 and DA15 then........may be next FA 31 or sigma 30

03-09-2013, 09:45 AM	#11
tclausen Veteran Member Join Date: May 2012 Posts: 1,397	Originally posted by Dynamo same here.... I started with DA 35 macro..then FA 77 and DA15 then........may be next FA 31 or sigma 30 Funny, I started with the 77mm - and the 35mm macro was my latest ltd. acquisition