Understand 50mm with K200D

josekj · 08-01-2008, 03:22 PM

I have 50mm lens that I attached to my Pentax K200D. It asks me to enter the focal length of the lens. Should I enter 50mm or should I enter the value based on the sensor crop (1.5 X) of 35mm. Or did I get it all wrong.

Some help would be appreciated.

Thanks

offertonhatter · 08-01-2008, 03:29 PM

Put in 50mm, as the SR calculates the length without the crop.

a 50mm will still be a 50mm lens, even if the effective FOV is 75mm.

josekj · 08-05-2008, 01:52 PM

Thanks for the reply, I put in 50mm, really like the lens.

nixcamic · 08-05-2008, 06:57 PM

A focal length is a focal length, it never changes (unless you have a zoom

). The 1.5x crop is for the field of view provided, to make it easyer for people used to 35mm film, not the actual focal lenth, so for anything besides calculating FOV based on the 35mm standard, use the actual focal length instead.

MissK · 08-06-2008, 03:49 AM

Does the camera ask you to put in focal length? How? I have a K10D and he has never asked me anything (except for "do you still love me even though K20D is here?")

.

Is that a new function or anything?

MrApollinax · 08-06-2008, 04:00 AM

It will ask you for the focal length if you have the following:

1. SR on
2. Have a manual lens on the camera

2 is important since older lenses cannot communicate the focal length to the camera so the user needs to input the length manually for SR to compensate correctly.

MissK · 08-06-2008, 04:29 AM

Originally posted by MrApollinax

It will ask you for the focal length if you have the following:

1. SR on
2. Have a manual lens on the camera

2 is important since older lenses cannot communicate the focal length to the camera so the user needs to input the length manually for SR to compensate correctly.

Ahaa... thanks! I only have FA and DA lenses so that's why I don't get that question. Thanks!

Wheatfield · 08-06-2008, 07:31 AM

Originally posted by josekj

I have 50mm lens that I attached to my Pentax K200D. It asks me to enter the focal length of the lens. Should I enter 50mm or should I enter the value based on the sensor crop (1.5 X) of 35mm. Or did I get it all wrong.

Some help would be appreciated.

Thanks

There is no such thing as a crop factor. A group of internet buffoons decided to come up with this concept in order to allow them to be mush brained idiots.
Learn to think of your lenses in terms of what they will do on the format you are using, not on some format you are not using.

And enter the focal length of the lens in use into the camera's shake reduction screen. The camera is smarter than it's user base from the looks of it. It doesn't care about silly crop factors.

ChrisA · 08-06-2008, 07:38 AM

Originally posted by Wheatfield

There is no such thing as a crop factor.

Of course there is. It's 2/3

audiobomber · 08-06-2008, 07:42 AM

Originally posted by Wheatfield

There is no such thing as a crop factor. A group of internet buffoons decided to come up with this concept in order to allow them to be mush brained idiots.
Learn to think of your lenses in terms of what they will do on the format you are using, not on some format you are not using.

Crop factor is an extremely useful way of comparing FOV on differing lens systems. It allows me to compare for example the zoom factor of my Canon A720 (36-210mm) with my DSLR lenses (24-450mm). How would you describe how an Olympus E-510 looks with a 300mm lens without crop factor or 35mm equivalent? Because it sure looks a lot different than a 300mm lens on a Pentax, i.e. 600mm vs 450mm.

josekj · 08-20-2008, 02:29 PM

Why does Pentax call it Kit lens 18-55mm lens (which in 35mm language - 28-82.5mm). Why do they use those terms to descibe lens. I understand that those lens can only be used with camera that have a 1.5X crop. Is that true?

sewebster · 08-20-2008, 02:40 PM

Originally posted by josekj

Why does Pentax call it Kit lens 18-55mm lens (which in 35mm language - 28-82.5mm). Why do they use those terms to descibe lens. I understand that those lens can only be used with camera that have a 1.5X crop. Is that true?

Because the lens has a focal length of 18-55 mm. "Focal length" is a defined "scientific" term and it means something in particular when applied to lenses. Regardless of what size sensor you put inside the camera, the lens doesn't change and it has a true focal length of 18-55 mm.

Focal length - Wikipedia, the free encyclopedia

flyer · 08-20-2008, 03:04 PM

I shoot 2 1/4 x 1 3/4, and, as far as I can remember, there was never a "crop factor" when comparing it to 35 mm cameras. There is no such thing as "crop factor", just an equivalent field of view. The APS-C sensor is not cropped, so why come with a "crop factor".

egordon99 · 08-20-2008, 06:38 PM

Because it's a lens which zooms from 18mm to 55mm?

Originally posted by josekj

Why does Pentax call it Kit lens 18-55mm lens

Big Dave · 08-20-2008, 10:50 PM

No one ever compared the medium format to the 35mm format. The 35mm format is the standard by which most hand held cameras are compared. So there for The term 35mm equivent has been used for some time now. The term crop factor is just used to describe the field of view. They used to call it the focal lenght multiplyer until somebody complained. A term that is in common use does exist of course.

Dave

Originally posted by flyer

I shoot 2 1/4 x 1 3/4, and, as far as I can remember, there was never a "crop factor" when comparing it to 35 mm cameras. There is no such thing as "crop factor", just an equivalent field of view. The APS-C sensor is not cropped, so why come with a "crop factor".

08-01-2008, 03:22 PM	#1
josekj Junior Member Join Date: Jul 2008 Location: Oklahoma City Posts: 30	Understand 50mm with K200D I have 50mm lens that I attached to my Pentax K200D. It asks me to enter the focal length of the lens. Should I enter 50mm or should I enter the value based on the sensor crop (1.5 X) of 35mm. Or did I get it all wrong. Some help would be appreciated. Thanks

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08-01-2008, 03:29 PM	#2
offertonhatter Veteran Member Join Date: Jul 2007 Location: North West UK Posts: 390	Put in 50mm, as the SR calculates the length without the crop. a 50mm will still be a 50mm lens, even if the effective FOV is 75mm.

08-05-2008, 01:52 PM	#3
josekj Junior Member Join Date: Jul 2008 Location: Oklahoma City Posts: 30 Original Poster	Thanks for the reply, I put in 50mm, really like the lens.

08-05-2008, 06:57 PM	#4
nixcamic Veteran Member Join Date: Jun 2008 Location: Guatemala Posts: 354	A focal length is a focal length, it never changes (unless you have a zoom ). The 1.5x crop is for the field of view provided, to make it easyer for people used to 35mm film, not the actual focal lenth, so for anything besides calculating FOV based on the 35mm standard, use the actual focal length instead.

08-06-2008, 03:49 AM	#5
MissK New Member Join Date: Aug 2008 Location: Sweden Posts: 13	Does the camera ask you to put in focal length? How? I have a K10D and he has never asked me anything (except for "do you still love me even though K20D is here?") . Is that a new function or anything?

08-06-2008, 04:00 AM	#6
MrApollinax Veteran Member Join Date: Apr 2008 Location: Minnesota Photos: Gallery Posts: 1,529	It will ask you for the focal length if you have the following: 1. SR on 2. Have a manual lens on the camera 2 is important since older lenses cannot communicate the focal length to the camera so the user needs to input the length manually for SR to compensate correctly.

08-06-2008, 04:29 AM	#7
MissK New Member Join Date: Aug 2008 Location: Sweden Posts: 13	Originally posted by MrApollinax It will ask you for the focal length if you have the following: 1. SR on 2. Have a manual lens on the camera 2 is important since older lenses cannot communicate the focal length to the camera so the user needs to input the length manually for SR to compensate correctly. Ahaa... thanks! I only have FA and DA lenses so that's why I don't get that question. Thanks!

08-06-2008, 07:31 AM	#8
Wheatfield Moderator Join Date: Apr 2008 Location: The wheatfields of Canada Posts: 15,981	Originally posted by josekj I have 50mm lens that I attached to my Pentax K200D. It asks me to enter the focal length of the lens. Should I enter 50mm or should I enter the value based on the sensor crop (1.5 X) of 35mm. Or did I get it all wrong. Some help would be appreciated. Thanks There is no such thing as a crop factor. A group of internet buffoons decided to come up with this concept in order to allow them to be mush brained idiots. Learn to think of your lenses in terms of what they will do on the format you are using, not on some format you are not using. And enter the focal length of the lens in use into the camera's shake reduction screen. The camera is smarter than it's user base from the looks of it. It doesn't care about silly crop factors.

08-06-2008, 07:38 AM	#9
ChrisA Veteran Member Join Date: Feb 2007 Location: London Posts: 393	Originally posted by Wheatfield There is no such thing as a crop factor. Of course there is. It's 2/3

08-06-2008, 07:42 AM	#10
audiobomber Veteran Member Join Date: May 2008 Location: Sudbury, Ontario Photos: Albums Posts: 6,806	Originally posted by Wheatfield There is no such thing as a crop factor. A group of internet buffoons decided to come up with this concept in order to allow them to be mush brained idiots. Learn to think of your lenses in terms of what they will do on the format you are using, not on some format you are not using. Crop factor is an extremely useful way of comparing FOV on differing lens systems. It allows me to compare for example the zoom factor of my Canon A720 (36-210mm) with my DSLR lenses (24-450mm). How would you describe how an Olympus E-510 looks with a 300mm lens without crop factor or 35mm equivalent? Because it sure looks a lot different than a 300mm lens on a Pentax, i.e. 600mm vs 450mm.

08-20-2008, 02:29 PM	#11
josekj Junior Member Join Date: Jul 2008 Location: Oklahoma City Posts: 30 Original Poster	Why does Pentax call it Kit lens 18-55mm lens (which in 35mm language - 28-82.5mm). Why do they use those terms to descibe lens. I understand that those lens can only be used with camera that have a 1.5X crop. Is that true?

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08-20-2008, 02:40 PM	#12
sewebster Veteran Member Join Date: Jun 2008 Location: Vancouver, BC Photos: Gallery Posts: 544	Originally posted by josekj Why does Pentax call it Kit lens 18-55mm lens (which in 35mm language - 28-82.5mm). Why do they use those terms to descibe lens. I understand that those lens can only be used with camera that have a 1.5X crop. Is that true? Because the lens has a focal length of 18-55 mm. "Focal length" is a defined "scientific" term and it means something in particular when applied to lenses. Regardless of what size sensor you put inside the camera, the lens doesn't change and it has a true focal length of 18-55 mm. Focal length - Wikipedia, the free encyclopedia

08-20-2008, 03:04 PM	#13
flyer Veteran Member Join Date: Jan 2008 Location: Ste-Anne des Plaines, Qc., Canada Posts: 2,013	I shoot 2 1/4 x 1 3/4, and, as far as I can remember, there was never a "crop factor" when comparing it to 35 mm cameras. There is no such thing as "crop factor", just an equivalent field of view. The APS-C sensor is not cropped, so why come with a "crop factor".

08-20-2008, 06:38 PM	#14
egordon99 Inactive Account Join Date: Dec 2006 Location: Outside of Philly Posts: 1,561	Because it's a lens which zooms from 18mm to 55mm? Originally posted by josekj Why does Pentax call it Kit lens 18-55mm lens

08-20-2008, 10:50 PM	#15
Big Dave Veteran Member Join Date: Jan 2008 Location: San Antonio, Texas Photos: Gallery Posts: 547	No one ever compared the medium format to the 35mm format. The 35mm format is the standard by which most hand held cameras are compared. So there for The term 35mm equivent has been used for some time now. The term crop factor is just used to describe the field of view. They used to call it the focal lenght multiplyer until somebody complained. A term that is in common use does exist of course. Dave Originally posted by flyer I shoot 2 1/4 x 1 3/4, and, as far as I can remember, there was never a "crop factor" when comparing it to 35 mm cameras. There is no such thing as "crop factor", just an equivalent field of view. The APS-C sensor is not cropped, so why come with a "crop factor".