Jump to content

Sigma 56mm F1.4 decentered

keepcoding

By keepcoding,
in Sony Alpha APS-C Lenses

 Share

Recommended Posts

keepcoding Enthusiast

keepcoding

Posted
Posted (edited)

Hi

I've had 2 copies of the Sigma 56mm F1.4 and both showed a rather severe decentering issue. The left side of the frame is quite blurry compared to the right side, especially between F1.4 and F2.8. Here is an example at F2.8, focused at infinity:

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

 

Note that it is not just the edge that is unsharp, it is approx. 50% of the left side of the frame.

I wonder if this is an issue with all lenses or just a faulty batch. Is there anyone with a good copy?

 

If you don't know how to test your lens, here is a simple recipe:

  • choose a scene that fills the entire frame with distant objects (should be several hundred meters away)
  • set the focus manually in the middle of the frame (should be around infinity)
  • set the aperture to e.g. F2.8 and take a photo
  • now rotate the camera 180° and take the same photo again (upside down) without changing the focus
  • compare the two shots
Edited by keepcoding
Link to post
Share on other sites
keepcoding Enthusiast

keepcoding

Posted
  • Author
Posted (edited)

Since editing my post is no longer possible, here some corrections:

  • the photo above was taken at F1.4, NOT F2.8
  • for the mentioned test procedure, it is better to use the max. available aperture of the lens

The decentering is also visible at F2.8, but is less severe.

Edited by keepcoding
Link to post
Share on other sites
Pieter Experienced

Pieter

Posted
Posted

Interesting, seems like pretty bad decentering indeed... I've not yet seen any reports about this lens being prone to decentering, but then two lemons in a row sounds like really really bad luck... The second shot seems pretty darn sharp for corners at f/1.4 though, quite in line with the analysis in my other topic about the comparison to the Sony Zeiss 55mm.

Let us know if you get lucky on the 3rd one! I'm just about to order one myself.

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Posts

    • bs.shoots
      2 Primes or 1 Zoom?

      By bs.shoots · Posted

      I recently got an a7cii and to pair with the compact body, I thought of getting 2 of the trio compact lenses, 24mm F2.8 and 40mm F4.0. (I already have a 70-200mm) However I stumbled upon the newly released 24-50mm F2.8 G. I'm not sure which to get - I like the small factor of the prime lenses ON the body because it's discreet and helps me blend in as an average tourist / doesn't make it obvious when doing street. But if I add the dimensions of the 2 primes together, it takes up more space in the bag than the zoom lens. BUT THEN, the weight of the 2 prime lenses is 110g lesser than the zoom lens. The zoom lens has the added benefit of being more versatile.   So now I'm stumped. Each has their pros and cons and I can't decide which to get. I'd like to hear the views of you guys who are more experts at this.   Edit: I'm a bit concerned about weight because the last time I went overseas my shoulders were aching from carrying too much. Which is why I was looking for small compact primes in the first place.
    • dev001
      Sony a6300 after shutter repair

      By dev001 · Posted

      Hi, I have got a6300 which shutter stopped working. I managed to change shutter but unfortunatelly broke shutter motor tape but I fixed that. After repair the shutter is working but not in a proper way, watch with sound. I bought the second shutter and tried to test it before dissaembling again and it doesn't react to magnet but it works fine when I apply 3V. Are there different type of shutter for a6000 - a6400? Back to the question what is wrong with my shutter after first repair? I don't want to put next shutter unfoundedly. Do your sony cameras perform such a self-check after start up?  IMG_5579 (1).webm
    • ikach
      Sony Alpha videos are missing

      By ikach · Posted

      PRIVATE\M4ROOT\CLIP I had the same issue Couldnt find the videos  even thought it played on the camera  found them all in here   

  • Topics

×
×
  • Create New...