Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
05-20-2011, 06:03 PM   #1
New Member




Join Date: May 2011
Location: London
Posts: 12
pentax 35 mm 2.4 very soft ?

I recently bought the new 35 mm 2.4 to mount on my K-x ( I usually use with the 16-45 perfect pictures)
All reviews explain this 35 is amazing but I all always get very soft to blurry or not focused pictures ! Is it normal for a large aperture 2.4 ?
I do low light pictures with that lens ( thats why I bought it) and it is impossible to use ... and it is quite the same in daylight

Please have a look at this pictures that is not a bad exception or a k-x AF problem as I repeated everything many times on so many pictures and compared with the 16-45 at f4.

What you think ?

Attached Images
 
05-20-2011, 06:18 PM   #2
Pentaxian
JohnBee's Avatar

Join Date: Sep 2008
Location: front of computer
Posts: 4,496
I think its fantastic!
05-20-2011, 06:20 PM   #3
Veteran Member




Join Date: Oct 2009
Location: United States
Photos: Gallery | Albums
Posts: 392
With the scene like you have posted, it is important to focus at the hyper-focal distance.
With f2.4 on a 35mm lens, hf distance will be too far from you...

The quick cheat is to focus on something 2/3rd of the way along teh depth -


Or use a smaller aperture, and a tripod and longer shutter time.


cheers,

Abhi
05-20-2011, 06:21 PM   #4
Veteran Member
paperbag846's Avatar

Join Date: Jul 2010
Photos: Gallery
Posts: 2,396
Turn off shake reduction for tripod shots.

05-20-2011, 06:25 PM   #5
New Member




Join Date: May 2011
Location: London
Posts: 12
Original Poster
ok seen on this small size it looks but here is a crop ....
I focused on the boat still

sure it shouldn't be better ? (f 2.4 1/30 ISO 400)
Attached Images
 
05-20-2011, 06:28 PM   #6
Pentaxian
Ratmagiclady's Avatar

Join Date: Nov 2008
Location: GA
Photos: Gallery | Albums
Posts: 13,464
Looks like you're just plain focused too short, but also, yes, turn off SR for tripod shots.
05-20-2011, 06:32 PM   #7
New Member




Join Date: May 2011
Location: London
Posts: 12
Original Poster
Dexmus, I am not sure to understand your knowledge, so I have to focus closer to me, about on the boardwalk to make the boat focused ? or I am wrong

I have tested with f4 it is perfect but I bought that lens to avoid using a tripod
05-20-2011, 06:34 PM   #8
New Member




Join Date: May 2011
Location: London
Posts: 12
Original Poster
it is not a tripod shot I never carry one and dont want,

I am not sure to understand : to make the boat focused I have to focus to infinity or closer to me, lets say on the boardwalk ?


Last edited by snoop21; 05-20-2011 at 06:45 PM.
05-20-2011, 06:54 PM   #9
New Member




Join Date: May 2011
Location: London
Posts: 12
Original Poster
another example ...
Attached Images
 
05-20-2011, 07:08 PM   #10
Veteran Member
RXrenesis8's Avatar

Join Date: Jan 2011
Location: Orlando, FL (USA)
Photos: Gallery | Albums
Posts: 523
For landscape at night with a standard lens like that just set the focus to manual and the focal distance halfway between the last distance marker and infinity.

35mm on APS-C @ f2.4 should have a hyperfocal distance of about 80 feet.

Oh, right... no focal distance markings... uuh, just focus on infinity and back it off a tiny bit?
05-20-2011, 07:21 PM   #11
New Member




Join Date: May 2011
Location: London
Posts: 12
Original Poster
ok I will try, but why the AF doesn't work ?

I am new in the dslr world...
05-20-2011, 07:29 PM   #12
Pentaxian
Ratmagiclady's Avatar

Join Date: Nov 2008
Location: GA
Photos: Gallery | Albums
Posts: 13,464
QuoteOriginally posted by snoop21 Quote
Dexmus, I am not sure to understand your knowledge, so I have to focus closer to me, about on the boardwalk to make the boat focused ? or I am wrong

I have tested with f4 it is perfect but I bought that lens to avoid using a tripod
To be quite honest, if you expected to do this routinely without a tripod you have a little bit to learn about camera handling. (THough it seems your steadiness is not the problem, really. Not bad) Not to say it's impossible, but you may well be complaining about the tech when you've got some skills to work on. Don't be ashamed, there: I *pride* myself on this kind of thing and after thirty years I don't always hit like that, even with SR.


It still appears you're focused short, so, focus a little longer (more distant) and then tell us how you do. That lens in general is quite good wide open, but you don't actually get infinite DOF out of hyperfocal anyway. (With faster glass I prefer to stop down to around there if I can, anyway.)


It does still look as though if you had another issue, your unsharpness would be more directional, so, if shooting that lens wde-open, choose your focus point and achieve it. (If you're relying on autofocus, it may take a correction, but in that light I really suggest manual. )

Last edited by Ratmagiclady; 05-20-2011 at 07:35 PM.
05-20-2011, 10:01 PM   #13
Veteran Member
wlachan's Avatar

Join Date: Sep 2006
Location: Canada
Photos: Albums
Posts: 2,626
The sample didn't seem to suffer from motion blur, but rather, focus error. Time to check BF/FF.
05-20-2011, 11:40 PM   #14
Veteran Member
Laurentiu Cristofor's Avatar

Join Date: Nov 2009
Location: WA
Photos: Albums
Posts: 3,044
QuoteOriginally posted by snoop21 Quote
All reviews explain this 35 is amazing but I all always get very soft to blurry or not focused pictures !
It is normal for shots that are not focused to look soft. That is why getting the focus right is critical. And with SLRs it is more critical than with P&Ss, so you have to keep an eye on what the AF system does and help it do better. Or you can manual focus.

QuoteOriginally posted by snoop21 Quote
ok seen on this small size it looks but here is a crop ....
I focused on the boat still
You seem to have focused somewhere closer than the first street light, which is a long way from the boat. You should focus at 26m away or more - just use the distance scale and focus manually for such simple shots. You can also take a bunch of shots while changing the focus and pick the best one - it's not like you're wasting film exposures if you do that.
05-20-2011, 11:55 PM   #15
Veteran Member




Join Date: Jan 2010
Location: Southern England
Posts: 495
For the purposes of getting to the bottom of this, I think we should concentrate on daylight shots - otherwise we don't know if the camera is misfocusing owing to the low light levels.

So, get the camera to focus on the ship in daylight. (I would set the camera to centre-spot focusing to ensure that you're actually focused on what you want - just recompose if necessary, with the shutter button held halfway to lock focus.)

If the results are blurred, then either the camera is misfocusing for some reason, or the lens is unsatisfactory (faulty). Try this for various apertures - you should find that the best aperture is about f5.6, and f2.4 ought to be slightly less sharp. If the image gets sharper and sharper as you stop down (i.e. increasing the f-number), and is sharpest at f16/f22, then there's something wrong. (But do post your results here, so we can help judge!)

In order to distinguish between misfocusing and a lens fault, you would need to experiment with closer objects, arranged at various distances from the camera - focus on one of the objects, and look to see which object is least blurred. Do this at f2.4 only.

If the camera is misfocusing (i.e. front-focusing (FF), or back-focusing (BF)), then you can probably adjust this in the K-x (I don't have one so can't advise here). Otherwise, I would try to return the lens as faulty.

So, assuming you clear up the lens-in-daylight problems, you can then turn to your low-light shots. Try to find out how low-light you can go before the camera's autofocus starts to fail. If you find it becomes unreliable at the light levels you're aiming for, then you need to investigate manual focus - which won't be easy either, because what looks like good focus in the viewfinder may well be quite blurred when you inspect the image.

Regarding hyperfocal focusing, this is a method which is commonly used for landscape photography, and the idea is that you manually set the lens's focus distance to something which will include the horizon (infinity) and as much foreground as possible, with acceptable sharpness. Ironically, this is much more easily accomplished with an old manual-focus lens, which will have a DOF scale. I don't think the 35/2.4 has even a distance scale, so it will be difficult.

But, as has been said, if you are able to set the lens to a focus distance of about 80 feet, you should find that you get satisfactory focus from about 50 feet to the horizon - even at f2.4. Then you won't need to touch the camera - just shoot away!
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!
k-mount, k-x, mm, pentax lens, pictures, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
The Soft Place: Post Your Soft Focus Images jeffkpotter Mini-Challenges, Games, and Photo Stories 64 04-22-2014 05:39 PM
Pentax Lens Soft Case dogbear1980 Pentax Camera and Field Accessories 5 04-12-2010 05:19 PM
Pentax 67 soft and inaccurate!!!! kohlton Pentax Medium Format 15 11-07-2009 03:13 AM
Pentax FA 85mm f2.8 soft Greg1209 Troubleshooting and Beginner Help 7 11-03-2009 09:18 AM
The Soft Place: Post Your Soft Focus Images jeffkpotter Post Your Photos! 22 04-23-2009 09:04 PM



All times are GMT -7. The time now is 04:23 AM. | See also: NikonForums.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