Win a Pentax Limited Lens: Raffle Now Live!

Scootatheschool1990 · 01-22-2013, 12:26 AM

What are the consequences or changes of putting an FA on an apsc lens? I see pentax makes majority of lenses as apsc. Why not make everything full frame so they work on both ff and apsc?

lytrytyr · 01-22-2013, 12:55 AM

Originally posted by Scootatheschool1990

Why not make everything full frame so they work on both ff and apsc?

Lenses can be made smaller and lighter
if they only have to cover the APS-C frame.
And if a lens is lighter, the AF works faster.

As a comparison, the DA 15/4 Ltd
is a lot smaller and lighter than the A 15/3.5,
even allowing for the latter's built-in filters.

lytrytyr · 01-22-2013, 12:58 AM

Originally posted by Scootatheschool1990

What are the consequences or changes of putting an FA on an apsc [camera]?

They'll work just fine.

You're cropping out a narrower field of view
from the central part of the FA lens's image circle.

Chaos_Realm · 01-22-2013, 01:04 AM

Originally posted by Scootatheschool1990

What are the consequences or changes of putting an FA on an apsc lens? I see pentax makes majority of lenses as apsc. Why not make everything full frame so they work on both ff and apsc?

Consequence is that you don't get the same field of view that then lens is designed to produce. This has implications relating to larger Depth of Field for the same shot among other things. But the reason they don't make full frame lenses is due to the lenses costing more as there need to be more glass in the lens. Typically an increase in size and weight comes with the increase in the size of glass elements inside.

Pentax has not FF sensor in production so it doesn't make sense to make people pay for what they don't need.

Scootatheschool1990 · 01-22-2013, 01:39 AM

Ohhh okay. So then my next question : is my 14mm2.8 really a 21 in 35mm format? I know it won't work on an ff camera.

AussieTrev · 01-22-2013, 01:40 AM

Great photos. The FA lenses are great lenses and often cheaper second hand.

DSims · 01-22-2013, 02:30 AM

Originally posted by Scootatheschool1990

Ohhh okay. So then my next question : is my 14mm2.8 really a 21 in 35mm format? I know it won't work on an ff camera.

Yes, it has an equivalent FOV to 21mm on a FF camera.

FWIW, I use FA lenses more than any other series (on my K-5 and K-5 IIs).

Sagitta · 01-22-2013, 02:31 AM

Originally posted by Scootatheschool1990

Ohhh okay. So then my next question : is my 14mm2.8 really a 21 in 35mm format? I know it won't work on an ff camera.

FA lenses are full frame lenses. Its the DA's that are APSC. Your FA 14mm f/2.8 was designed for a film camera back in 'The Day' and as such would work on a FF Pentax digital camera should such a critter actually exist.

**boriscleto** · 01-22-2013, 07:02 AM

Originally posted by Scootatheschool1990

Ohhh okay. So then my next question : is my 14mm2.8 really a 21 in 35mm format? I know it won't work on an ff camera.

No a 14mm lens is a 14mm lens. To get the same field of view on a FF you would use a 21mm. To get the same field of view on M4/3 you would have to use a 10mm lens.

lytrytyr · 01-22-2013, 11:04 AM

Originally posted by Sagitta

FA lenses are full frame lenses. Its the DA's that are APSC. Your FA 14mm f/2.8 was designed for a film camera back in 'The Day' and as such would work on a FF Pentax digital camera should such a critter actually exist.

I think OP is referring here to the DA 14/2.8,
which was designed for APS-C format
(and which apparently now has the dubious distinction
of being the first DA lens to be discontinued.)

**boriscleto** · 01-22-2013, 11:09 AM

Originally posted by lytrytyr

I think OP is referring here to the DA 14/2.8,
which was designed for APS-C format
(and which apparently now has the dubious distinction
of being the first DA lens to be discontinued.)

The OP has to be referring to the DA 14, it is the only 14mm lens Pentax has produced.

lytrytyr · 01-22-2013, 11:30 AM

Originally posted by boriscleto

The OP has to be referring to the DA 14, it is the only 14mm lens Pentax has produced.

Exactly.

Sagitta · 01-22-2013, 04:18 PM

Originally posted by lytrytyr

Exactly.

Oh, durrr on me. The OP threw me in asking about FA lenses and I didn't bother doublechecking whether there was an FA version or not of the 14mm.

The fact I've been pricing the Samyang 14mm's today (which ARE ff) also messed with my head.

stevebrot · 01-22-2013, 05:16 PM

Originally posted by Scootatheschool1990

14mm2.8 really a 21 in 35mm format

No...your 14mm is a 14mm regardless. What happens in 35mm format is that the FOV is 1.5x wider then with APS-C. I would caution that that extra FOV needs to be matched by a bigger image circle or you will git huge shadows in the corners.

Steve

lytrytyr · 01-23-2013, 04:15 AM

Originally posted by Sagitta

The fact I've been pricing the Samyang 14mm's today (which ARE ff) also messed with my head.

If you get one, please show us what you do with it.

I use wide angles for architecture (among other things),
so the 5% barrel distortion would bother me,
and correcting it would kill some of the lens's great edge resolution.

01-22-2013, 12:26 AM	#1
Scootatheschool1990 Veteran Member Join Date: Jun 2012 Location: Boise Idaho Photos: Gallery \| Albums Posts: 466	Fa lenses on my k5? What are the consequences or changes of putting an FA on an apsc lens? I see pentax makes majority of lenses as apsc. Why not make everything full frame so they work on both ff and apsc?

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Contax lenses on K5	Pontax	Pentax K-5 & K-5 II	13	12-11-2012 06:28 AM
Lens compatibility confirmation: Will my MZ-30 lenses work on K5 or K5 II?	RachaelJamess	Visitors' Center	4	11-22-2012 10:23 AM
Manual lenses on K5	Paunel	Pentax K-5 & K-5 II	2	09-29-2011 10:54 AM
Can I use F, FA and FA J lenses on my ist D/ist DS?	Ole	Pentax DSLR and Camera Articles	4	03-16-2008 01:10 PM

01-22-2013, 12:55 AM	#2
lytrytyr Pentaxian Join Date: Nov 2011 Photos: Gallery \| Albums Posts: 4,310	Originally posted by Scootatheschool1990 Why not make everything full frame so they work on both ff and apsc? Lenses can be made smaller and lighter if they only have to cover the APS-C frame. And if a lens is lighter, the AF works faster. As a comparison, the DA 15/4 Ltd is a lot smaller and lighter than the A 15/3.5, even allowing for the latter's built-in filters.

01-22-2013, 12:58 AM	#3
lytrytyr Pentaxian Join Date: Nov 2011 Photos: Gallery \| Albums Posts: 4,310	Originally posted by Scootatheschool1990 What are the consequences or changes of putting an FA on an apsc [camera]? They'll work just fine. You're cropping out a narrower field of view from the central part of the FA lens's image circle.

01-22-2013, 01:04 AM	#4
Chaos_Realm Veteran Member Join Date: Feb 2011 Location: Melbourne, Australia Photos: Gallery \| Albums Posts: 1,251	Originally posted by Scootatheschool1990 What are the consequences or changes of putting an FA on an apsc lens? I see pentax makes majority of lenses as apsc. Why not make everything full frame so they work on both ff and apsc? Consequence is that you don't get the same field of view that then lens is designed to produce. This has implications relating to larger Depth of Field for the same shot among other things. But the reason they don't make full frame lenses is due to the lenses costing more as there need to be more glass in the lens. Typically an increase in size and weight comes with the increase in the size of glass elements inside. Pentax has not FF sensor in production so it doesn't make sense to make people pay for what they don't need.

01-22-2013, 01:39 AM	#5
Scootatheschool1990 Veteran Member Join Date: Jun 2012 Location: Boise Idaho Photos: Gallery \| Albums Posts: 466 Original Poster	Ohhh okay. So then my next question : is my 14mm2.8 really a 21 in 35mm format? I know it won't work on an ff camera.

01-22-2013, 01:40 AM	#6
AussieTrev Veteran Member Join Date: Jul 2010 Location: Queensland Photos: Gallery \| Albums Posts: 3,590	Great photos. The FA lenses are great lenses and often cheaper second hand.

01-22-2013, 02:30 AM	#7
DSims Veteran Member Join Date: Sep 2009 Location: Southern California Photos: Gallery \| Albums Posts: 3,236	Originally posted by Scootatheschool1990 Ohhh okay. So then my next question : is my 14mm2.8 really a 21 in 35mm format? I know it won't work on an ff camera. Yes, it has an equivalent FOV to 21mm on a FF camera. FWIW, I use FA lenses more than any other series (on my K-5 and K-5 IIs).

01-22-2013, 02:31 AM	#8
Sagitta Veteran Member Join Date: Feb 2011 Location: Maine Photos: Gallery Posts: 3,081	Originally posted by Scootatheschool1990 Ohhh okay. So then my next question : is my 14mm2.8 really a 21 in 35mm format? I know it won't work on an ff camera. FA lenses are full frame lenses. Its the DA's that are APSC. Your FA 14mm f/2.8 was designed for a film camera back in 'The Day' and as such would work on a FF Pentax digital camera should such a critter actually exist.

01-22-2013, 07:02 AM	#9
boriscleto Loyal Site Supporter Join Date: Dec 2009 Location: North Syracuse, NY Photos: Gallery Posts: 16,477	Originally posted by Scootatheschool1990 Ohhh okay. So then my next question : is my 14mm2.8 really a 21 in 35mm format? I know it won't work on an ff camera. No a 14mm lens is a 14mm lens. To get the same field of view on a FF you would use a 21mm. To get the same field of view on M4/3 you would have to use a 10mm lens.

01-22-2013, 11:04 AM	#10
lytrytyr Pentaxian Join Date: Nov 2011 Photos: Gallery \| Albums Posts: 4,310	Originally posted by Sagitta FA lenses are full frame lenses. Its the DA's that are APSC. Your FA 14mm f/2.8 was designed for a film camera back in 'The Day' and as such would work on a FF Pentax digital camera should such a critter actually exist. I think OP is referring here to the DA 14/2.8, which was designed for APS-C format (and which apparently now has the dubious distinction of being the first DA lens to be discontinued.)

01-22-2013, 11:09 AM	#11
boriscleto Loyal Site Supporter Join Date: Dec 2009 Location: North Syracuse, NY Photos: Gallery Posts: 16,477	Originally posted by lytrytyr I think OP is referring here to the DA 14/2.8, which was designed for APS-C format (and which apparently now has the dubious distinction of being the first DA lens to be discontinued.) The OP has to be referring to the DA 14, it is the only 14mm lens Pentax has produced.

01-22-2013, 11:30 AM	#12
lytrytyr Pentaxian Join Date: Nov 2011 Photos: Gallery \| Albums Posts: 4,310	Originally posted by boriscleto The OP has to be referring to the DA 14, it is the only 14mm lens Pentax has produced. Exactly.

01-22-2013, 04:18 PM	#13
Sagitta Veteran Member Join Date: Feb 2011 Location: Maine Photos: Gallery Posts: 3,081	Originally posted by lytrytyr Exactly. Oh, durrr on me. The OP threw me in asking about FA lenses and I didn't bother doublechecking whether there was an FA version or not of the 14mm. The fact I've been pricing the Samyang 14mm's today (which ARE ff) also messed with my head.

01-22-2013, 05:16 PM	#14
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by Scootatheschool1990 14mm2.8 really a 21 in 35mm format No...your 14mm is a 14mm regardless. What happens in 35mm format is that the FOV is 1.5x wider then with APS-C. I would caution that that extra FOV needs to be matched by a bigger image circle or you will git huge shadows in the corners. Steve

01-23-2013, 04:15 AM	#15
lytrytyr Pentaxian Join Date: Nov 2011 Photos: Gallery \| Albums Posts: 4,310	Originally posted by Sagitta The fact I've been pricing the Samyang 14mm's today (which ARE ff) also messed with my head. If you get one, please show us what you do with it. I use wide angles for architecture (among other things), so the 5% barrel distortion would bother me, and correcting it would kill some of the lens's great edge resolution.

Fa lenses on my k5?

Win a Pentax Limited Lens: Raffle Now Live!