Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
05-12-2017, 09:43 AM   #1
Veteran Member
kooks's Avatar

Join Date: Apr 2011
Location: San Josť, Costa Rica
Photos: Albums
Posts: 794
FA 20mm 2.8 performance with K1 at low light??

Hello guys.. i kind of want a wide angle lens to match my K1.. mainly i will use this lens at low light situations, so im wondering, have any of you tried the K1 with the FA 20mm or the 20-35mm at low light?? How is the hunting?? im kind of worry that this lenses would struggle at dim light to lock focus. I own the Tokina 19-35 but the IQ some how i feel it not that good.

I dont want the 15-30mm cuz #1 is heavy #2 is much expensive #3. for the kind of shots where i would use the lens the reasos #1 and #2 doesnt justify the price.

05-12-2017, 09:50 AM   #2
Site Supporter
Site Supporter
mattt's Avatar

Join Date: Feb 2011
Location: Niagara
Photos: Gallery | Albums
Posts: 3,737
@SandyHancock can fill you in.
05-12-2017, 12:31 PM   #3
Site Supporter
Site Supporter
jatrax's Avatar

Join Date: May 2010
Location: Washington Cascades
Photos: Gallery | Albums
Posts: 12,991
QuoteOriginally posted by kooks Quote
im kind of worry that this lenses would struggle at dim light to lock focus.
Why are you worried? Curious what the logic is on that, especially on the FA 20mm f/2.8. The 20-35 is f/4, so slower but still should not be an issue. Surely AF lock is a function of the camera not the lens, provided the lens is bright enough?

I have used the FA 20-35 on the K-1 extensively but without knowing your definition of 'low light' is it difficult to say if it would suit you. This shot is with the DFA 24-70 @ f/5 and focus locked reliably. This is inside a refrigerator and the only illumination is my cell phone. Several other people with other brand cameras trying the same shot at the same time. One I know was using a Nikon with 50mm f/1.4 lens. I was the only one to get good images which I attribute to the low light ability of the K-1.
Attached Images
View Picture EXIF
PENTAX K-1  Photo 
05-12-2017, 03:49 PM   #4
Veteran Member
kooks's Avatar

Join Date: Apr 2011
Location: San Josť, Costa Rica
Photos: Albums
Posts: 794
Original Poster
QuoteOriginally posted by jatrax Quote
Why are you worried? Curious what the logic is on that, especially on the FA 20mm f/2.8.
well some lenses are known to hunt for focus more than others.. my question was.. how is the hunting of the FA 20mm or the FA 20-35 match with the low light performance of the K1??

I shoot weddings so a good example of "low light" could be a wedding reception, for example the dance part.

05-12-2017, 03:52 PM   #5
Administrator
Site Webmaster
Adam's Avatar

Join Date: Sep 2006
Location: Arizona
Photos: Gallery | Albums
Posts: 50,731
At F2.8 youll get close to optimal AF performance. The K-1 and all of the other -3 EV Pentax models all do a good job. I recently shot a show with the 28-105mm and didn't have any issues even at the long end.

Adam
PentaxForums.com Webmaster (Site Usage Guide | Site Help | My Photography)



PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

05-12-2017, 04:59 PM   #6
Site Supporter
Site Supporter
jatrax's Avatar

Join Date: May 2010
Location: Washington Cascades
Photos: Gallery | Albums
Posts: 12,991
QuoteOriginally posted by kooks Quote
well some lenses are known to hunt for focus more than others
Most lenses "known to hunt" are either slow consumer zooms like the DA 55-300 or macro types that have very long focus throw. Neither of which is the case with your two examples. Anyway, I cannot help with the FA 20mm, I do not have one. But the FA 20-35 is fine, IMHO. I don't use it inside much, mostly landscapes but never remember it hunting at all.

Just tested it in a closet. I had to use ISO 9,000 to get the shutter speed up to 1/10 at F/4 to show you how dark it was. No hunting at all, just chirp, focus lock. Tried it about 30 times at different focal lengths. Not really a scientific test but maybe it will help.
05-13-2017, 03:23 AM   #7
Veteran Member
kooks's Avatar

Join Date: Apr 2011
Location: San Josť, Costa Rica
Photos: Albums
Posts: 794
Original Poster
QuoteOriginally posted by jatrax Quote
Just tested it in a closet. I had to use ISO 9,000 to get the shutter speed up to 1/10 at F/4 to show you how dark it was. No hunting at all, just chirp, focus lock. Tried it about 30 times at different focal lengths. Not really a scientific test but maybe it will help.
Good to know .. Thanks for the test.

Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
20mm, 20mm 2.8 performance, fa, fa 20mm, im, k-mount, k1, lens, light, pentax lens, performance with k1, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
DA 40mm Ltd low light performance with Kx Bui Pentax SLR Lens Discussion 42 01-24-2017 09:52 AM
K1 and performance with 20mm A f2.8, 24mm f2.8 A, and 20-35 FA F4 stemked Pentax Full Frame 17 11-22-2016 11:53 AM
Machinery Low light K-1 Performance Peter Nutkins Post Your Photos! 10 05-03-2016 10:54 PM
Low light performance improvement; K-3ii over K-30? Newtophotos Pentax DSLR Discussion 6 11-04-2015 06:32 PM
K30 Low light performance mellowyeahlow Pentax K-30 & K-50 31 06-08-2015 03:35 PM



All times are GMT -7. The time now is 01:55 PM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top