Question regarding FA 31mm f/1.8

Mystic · 03-16-2011, 02:56 PM

Hello, I currently own DAL 35mm f/2.4 i'm very satisffied with it, however, two things bother me.
better bokeh
and wider FL
so

the answer is FA 31mm

My question is will FA 31mm have the same or even better low light AF?

or will it be slower?

because this factor might be the main factor in whether I will be able to take the pic or not.

and if not, then it doesn't matter if it's bokeh is better, it's not existing..

so, those who could compare, low light AF of both lenses, which one is better.

I would be very gratefull.

hcc · 03-16-2011, 04:28 PM

I do not have the 35mm but I have the FA31 mm f1.8. I can compare it with my Voigtlander 58mm f1.4 and my Tamron 90mm f2.8.

The FA31mm f1.8 is doing very well in low-light. It is certainly fast, almost as fast my Voigtlander (f1.4). My FA31mm is definitely much faster than my tammy f2.8.

I would expect that the FA31mm be quite faster than the 35mm f2.4.

Hope that the comment will help.

Wheatfield · 03-16-2011, 05:55 PM

The 31 is better, but not by an astonishing margin.

Woops, I read that as DA35, not DAL.
Forget whatever you read from me.

paperbag846 · 03-16-2011, 09:07 PM

AF will likely be more hit and miss in low light compared with the DAL because of the wider aperture, which results in lower contrast that can be taxing on the AF system in low light.

Whether it will be substantially different though, I cannot say. It would likely be just fine, however moderate-aperture lenses like the DAL tend to be the fastest in the AF department.

twitch · 03-16-2011, 09:16 PM

I think you will struggle to find someone who owns the DAL35 and the FA31. If someone owns the FA31 why would they buy the DAL35, and if someone had the budget to only buy a DAL35 a couple of months ago, how many would have found $1k so soon for a FA31.

My 2cents, as I own the FA31, is that I haven't noticed it to have slow AF at all. My gut feelking is that it is slower than my DA40 & DA21 which really are very fast, and about the same speed as my DA70. It's certainly faster than my 50-135, but then what isn't

axl · 03-17-2011, 01:02 AM

from personal experience, I don't think the AF will be slow on K-7/5 bodies but as paperbag wrote, it may be bit of hit and miss.

Mystic · 03-17-2011, 03:20 AM

First of all thank you all for your responses.

Originally posted by hcc

I do not have the 35mm but I have the FA31 mm f1.8. I can compare it with my Voigtlander 58mm f1.4 and my Tamron 90mm f2.8.

The FA31mm f1.8 is doing very well in low-light. It is certainly fast, almost as fast my Voigtlander (f1.4). My FA31mm is definitely much faster than my tammy f2.8.

I would expect that the FA31mm be quite faster than the 35mm f2.4.

Hope that the comment will help.

well thanks for sharing your experience. however I do not know what to make of it

since I never used or even seen any voigtlanders in use.

Originally posted by Wheatfield

The 31 is better, but not by an astonishing margin.

Woops, I read that as DA35, not DAL.
Forget whatever you read from me.

so.. if it's better not by astonishing amount than the da35 f/2.8 hmm.. ok, i'll have that in mind..

Originally posted by paperbag846

AF will likely be more hit and miss in low light compared with the DAL because of the wider aperture, which results in lower contrast that can be taxing on the AF system in low light.

Whether it will be substantially different though, I cannot say. It would likely be just fine, however moderate-aperture lenses like the DAL tend to be the fastest in the AF department.

well that doesn't mean that i'll be shooting at 1.8. I might be shooting at f/2 or f/2.2.. so since the FL of 31 is a bit wider the focal plane will be somewhere the same.

Originally posted by twitch

I think you will struggle to find someone who owns the DAL35 and the FA31. If someone owns the FA31 why would they buy the DAL35, and if someone had the budget to only buy a DAL35 a couple of months ago, how many would have found $1k so soon for a FA31.

My 2cents, as I own the FA31, is that I haven't noticed it to have slow AF at all. My gut feelking is that it is slower than my DA40 & DA21 which really are very fast, and about the same speed as my DA70. It's certainly faster than my 50-135, but then what isn't

hmm.. I guess I'll have to test DA70 first

to find out the speed of 31mm

DA70 is much easier to obtain here, where I live. I do believe there is someone who awns both. I might be wrong but.. Hin's blog that guy I think he has both of them..

Hin's Tech Corner

Originally posted by axl

from personal experience, I don't think the AF will be slow on K-7/5 bodies but as paperbag wrote, it may be bit of hit and miss.

I use Kr, and for not being hit and miss I will not use f/1.8 i'd close it a little.

thanks again everyone, for your input, i'll keep on researching.

paperbag846 · 03-17-2011, 04:24 AM

You should not be dissuaded from trying the FA 31 because of AF!

Stopping the lens down might help sometimes, might not help sometimes. Since the camera focuses wide open, stopping the lens down won't speed the lens up.

hcc · 03-17-2011, 04:27 AM

Originally posted by Mystic

well thanks for sharing your experience. however I do not know what to make of it

since I never used or even seen any voigtlanders in use.

Maybe I was not clear enough. I try again. In low light, the speed of your lens will be linked with the lens aperture. The larger the aperture, the more light goes into the sensor and the faster the lens. A large aperture means a low f. Hence a f1.4 lens will be faster than a f1.8 lens, itslef faster than a f2.4 lens, everything else being equal.

In other words, my comments were related to the lens aperture rather than the lens brand itself. The FA31mm is a f1.8. When shooting in low light at full aperture (f1.8), it will be faster (or can be used with a faster shutter speed) than a lens set at f2.8.

Hope that the comment will help...

VaughnA · 03-17-2011, 04:32 AM

Originally posted by hcc

Maybe I was not clear enough. ...

He's asking about autofocus speed, not actual lens speed.

Pentaxor · 03-17-2011, 08:18 PM

AF speed? DA35/2.4

Mystic · 03-18-2011, 04:38 AM

Originally posted by VaughnA

He's asking about autofocus speed, not actual lens speed.

yes, you are right . Thanks

Originally posted by Pentaxor

AF speed? DA35/2.4

what do you mean? is AF speed of DAL35/24 is quick or what?

03-16-2011, 02:56 PM	#1
Mystic Veteran Member Join Date: Feb 2009 Location: Lithuania Photos: Gallery Posts: 490	Question regarding FA 31mm f/1.8 Hello, I currently own DAL 35mm f/2.4 i'm very satisffied with it, however, two things bother me. better bokeh and wider FL so the answer is FA 31mm My question is will FA 31mm have the same or even better low light AF? or will it be slower? because this factor might be the main factor in whether I will be able to take the pic or not. and if not, then it doesn't matter if it's bokeh is better, it's not existing.. so, those who could compare, low light AF of both lenses, which one is better. I would be very gratefull.

03-16-2011, 05:55 PM	#3
Wheatfield Moderator Join Date: Apr 2008 Location: The wheatfields of Canada Posts: 15,981	The 31 is better, but not by an astonishing margin. Woops, I read that as DA35, not DAL. Forget whatever you read from me. Last edited by Wheatfield; 03-16-2011 at 09:15 PM.

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03-16-2011, 04:28 PM	#2
hcc Pentaxian Join Date: Nov 2009 Location: Brisbane, Australia Photos: Gallery \| Albums Posts: 4,002	I do not have the 35mm but I have the FA31 mm f1.8. I can compare it with my Voigtlander 58mm f1.4 and my Tamron 90mm f2.8. The FA31mm f1.8 is doing very well in low-light. It is certainly fast, almost as fast my Voigtlander (f1.4). My FA31mm is definitely much faster than my tammy f2.8. I would expect that the FA31mm be quite faster than the 35mm f2.4. Hope that the comment will help.

03-16-2011, 09:07 PM	#4
paperbag846 Veteran Member Join Date: Jul 2010 Photos: Gallery Posts: 2,395	AF will likely be more hit and miss in low light compared with the DAL because of the wider aperture, which results in lower contrast that can be taxing on the AF system in low light. Whether it will be substantially different though, I cannot say. It would likely be just fine, however moderate-aperture lenses like the DAL tend to be the fastest in the AF department.

03-16-2011, 09:16 PM	#5
twitch Veteran Member Join Date: Nov 2009 Posts: 4,571	I think you will struggle to find someone who owns the DAL35 and the FA31. If someone owns the FA31 why would they buy the DAL35, and if someone had the budget to only buy a DAL35 a couple of months ago, how many would have found $1k so soon for a FA31. My 2cents, as I own the FA31, is that I haven't noticed it to have slow AF at all. My gut feelking is that it is slower than my DA40 & DA21 which really are very fast, and about the same speed as my DA70. It's certainly faster than my 50-135, but then what isn't

03-17-2011, 01:02 AM	#6
axl Veteran Member Join Date: Mar 2007 Location: Nove Zamky, Slovakia Photos: Gallery \| Albums Posts: 7,183	from personal experience, I don't think the AF will be slow on K-7/5 bodies but as paperbag wrote, it may be bit of hit and miss.

03-17-2011, 03:20 AM	#7
Mystic Veteran Member Join Date: Feb 2009 Location: Lithuania Photos: Gallery Posts: 490 Original Poster	First of all thank you all for your responses. Originally posted by hcc I do not have the 35mm but I have the FA31 mm f1.8. I can compare it with my Voigtlander 58mm f1.4 and my Tamron 90mm f2.8. The FA31mm f1.8 is doing very well in low-light. It is certainly fast, almost as fast my Voigtlander (f1.4). My FA31mm is definitely much faster than my tammy f2.8. I would expect that the FA31mm be quite faster than the 35mm f2.4. Hope that the comment will help. well thanks for sharing your experience. however I do not know what to make of it since I never used or even seen any voigtlanders in use. Originally posted by Wheatfield The 31 is better, but not by an astonishing margin. Woops, I read that as DA35, not DAL. Forget whatever you read from me. so.. if it's better not by astonishing amount than the da35 f/2.8 hmm.. ok, i'll have that in mind.. Originally posted by paperbag846 AF will likely be more hit and miss in low light compared with the DAL because of the wider aperture, which results in lower contrast that can be taxing on the AF system in low light. Whether it will be substantially different though, I cannot say. It would likely be just fine, however moderate-aperture lenses like the DAL tend to be the fastest in the AF department. well that doesn't mean that i'll be shooting at 1.8. I might be shooting at f/2 or f/2.2.. so since the FL of 31 is a bit wider the focal plane will be somewhere the same. Originally posted by twitch I think you will struggle to find someone who owns the DAL35 and the FA31. If someone owns the FA31 why would they buy the DAL35, and if someone had the budget to only buy a DAL35 a couple of months ago, how many would have found $1k so soon for a FA31. My 2cents, as I own the FA31, is that I haven't noticed it to have slow AF at all. My gut feelking is that it is slower than my DA40 & DA21 which really are very fast, and about the same speed as my DA70. It's certainly faster than my 50-135, but then what isn't hmm.. I guess I'll have to test DA70 first to find out the speed of 31mm DA70 is much easier to obtain here, where I live. I do believe there is someone who awns both. I might be wrong but.. Hin's blog that guy I think he has both of them.. Hin's Tech Corner Originally posted by axl from personal experience, I don't think the AF will be slow on K-7/5 bodies but as paperbag wrote, it may be bit of hit and miss. I use Kr, and for not being hit and miss I will not use f/1.8 i'd close it a little. thanks again everyone, for your input, i'll keep on researching.

03-17-2011, 04:24 AM	#8
paperbag846 Veteran Member Join Date: Jul 2010 Photos: Gallery Posts: 2,395	You should not be dissuaded from trying the FA 31 because of AF! Stopping the lens down might help sometimes, might not help sometimes. Since the camera focuses wide open, stopping the lens down won't speed the lens up.

03-17-2011, 04:27 AM	#9
hcc Pentaxian Join Date: Nov 2009 Location: Brisbane, Australia Photos: Gallery \| Albums Posts: 4,002	Originally posted by Mystic well thanks for sharing your experience. however I do not know what to make of it since I never used or even seen any voigtlanders in use. Maybe I was not clear enough. I try again. In low light, the speed of your lens will be linked with the lens aperture. The larger the aperture, the more light goes into the sensor and the faster the lens. A large aperture means a low f. Hence a f1.4 lens will be faster than a f1.8 lens, itslef faster than a f2.4 lens, everything else being equal. In other words, my comments were related to the lens aperture rather than the lens brand itself. The FA31mm is a f1.8. When shooting in low light at full aperture (f1.8), it will be faster (or can be used with a faster shutter speed) than a lens set at f2.8. Hope that the comment will help...

03-17-2011, 04:32 AM	#10
VaughnA Banned Join Date: Feb 2009 Location: Virginia Photos: Gallery \| Albums Posts: 1,363	Originally posted by hcc Maybe I was not clear enough. ... He's asking about autofocus speed, not actual lens speed.

03-17-2011, 08:18 PM	#11
Pentaxor Veteran Member Join Date: May 2009 Location: Vancouver, B.C. Photos: Gallery Posts: 6,513	AF speed? DA35/2.4

03-18-2011, 04:38 AM	#12
Mystic Veteran Member Join Date: Feb 2009 Location: Lithuania Photos: Gallery Posts: 490 Original Poster	Originally posted by VaughnA He's asking about autofocus speed, not actual lens speed. yes, you are right . Thanks Originally posted by Pentaxor AF speed? DA35/2.4 what do you mean? is AF speed of DAL35/24 is quick or what?