Jump to content

Dark upper corners using FE 35mm/1.8 in small aperture and infinity focus


Recommended Posts

Advertisement (gone after registration)

Just bought the lens. Test it and very happy until I noticed dark upper corners, worse in the left. It only show up at small aperture (eg F11 F16 F22)and focus at infinity. The smaller the aperture the worse.
its worst in my A7II. Less noticeable in the A7RII. No hood or filter attached.

Picture shown is taken by A7II:

any idea what’s the cause? Please help. Can see the dark corner in EVF while composing and focusing 

All camera have updated firmware.

 

DE5607EB-4E0B-41ED-9D49-9EEBF979EA2F.jpeg

0381EC7D-C3D9-4E8F-A9F1-5C36881817E1.jpeg

Link to post
Share on other sites

To me this doesn't seem normal: regular vignetting gets less when closing down the aperture, not worse. Also, regular vignetting should be fairly similar for all corners and should gradually reduce towards the center.

In some lenses RAW-files show dark corners like these, but this is by design due to barrel-distortion and a small image circle (after digital correction the image is fine). The FE35 f/1.8 however has very little distortion and you say the dark corners are also in the viewfinder, which should be corrected for distortion. Just to be sure, do double-check if distortion compensation is enabled in your camera.

Given your observation that it gets worse when closing down and focussing at infinity, to me it sounds like something at the rear side of your lens is obstructing light rays from hitting the sensor. A small aperture combined with infinity focus results in very parallel light rays hitting the sensor, making physical obstructions close to the sensor very visible (also used as a method to spot dust on the sensor).

Perhaps have a look at the rear side of your lens to see if you can spot anything irregular, like a loose/shifted baffle.

Edited by Pieter
Link to post
Share on other sites
4 hours ago, Pieter said:

To me this doesn't seem normal: regular vignetting gets less when closing down the aperture, not worse. Also, regular vignetting should be fairly similar for all corners and should gradually reduce towards the center.

In some lenses RAW-files show dark corners like these, but this is by design due to barrel-distortion and a small image circle (after digital correction the image is fine). The FE35 f/1.8 however has very little distortion and you say the dark corners are also in the viewfinder, which should be corrected for distortion. Just to be sure, do double-check if distortion compensation is enabled in your camera.

Given your observation that it gets worse when closing down and focussing at infinity, to me it sounds like something at the rear side of your lens is obstructing light rays from hitting the sensor. A small aperture combined with infinity focus results in very parallel light rays hitting the sensor, making physical obstructions close to the sensor very visible (also used as a method to spot dust on the sensor).

Perhaps have a look at the rear side of your lens to see if you can spot anything irregular, like a loose/shifted baffle.

Checked. The rear end of the lens looks fine to me. Thanks for suggestions.

lens compensation is on for all parameters too. 

Edited by eggwah123
Link to post
Share on other sites

I don't own this specific lens so can't double-check if other copies behave the same. Perhaps some other reader can?

I'd be pretty annoyed if this was my lens: sounds like the lens is engineered slightly too tight. If you still have warranty I'd check with the store if they can let you try another copy.

Link to post
Share on other sites
5 minutes ago, Pieter said:

I don't own this specific lens so can't double-check if other copies behave the same. Perhaps some other reader can?

I'd be pretty annoyed if this was my lens: sounds like the lens is engineered slightly too tight. If you still have warranty I'd check with the store if they can let you try another copy.

Just received it two days ago. Will return it. But still want to know the cause and may be It’s a simple issue to resolve Without returning it.. Googled and found no one reported any similar issues. That’s strange or I am just exceptionally unlucky.

Anyone own this lens can run a test? F22 and focus at infinity. Any dark corners like the picture I posted above?

Edited by eggwah123
Link to post
Share on other sites

Advertisement (gone after registration)

Lenstip just tested this lens and, interestingly, their findings seem to agree with yours: when stopping down, in general the vignetting gets less but the extreme corners seriously lag behind. This causes the corners to stand out more in apparent darkness at small apertures. In their case however all corners are similarly dark, so there was something decentered in your copy.

https://www.lenstip.com/593.8-Lens_review-Sony_FE_35_mm_f_1.8_Vignetting.html

Link to post
Share on other sites
10 hours ago, Pieter said:

Lenstip just tested this lens and, interestingly, their findings seem to agree with yours: when stopping down, in general the vignetting gets less but the extreme corners seriously lag behind. This causes the corners to stand out more in apparent darkness at small apertures. In their case however all corners are similarly dark, so there was something decentered in your copy.

https://www.lenstip.com/593.8-Lens_review-Sony_FE_35_mm_f_1.8_Vignetting.html

Returned it by post already. Hopefully Sony will admit the defect and tell me what is the defect. Unlikely though.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
  • Posts

    • Perfectly understandable - American Greenback rules in most countries, not much different in Canada though without the 2 tier exchange rates.  Let us know when you have it and show us what it can do.
    • Here, in my country, our economy has always been very peculiar, unstable, and full of ups and downs. Nowadays, the official rate of exchange for the US dollar is 1 dollar = 103 AR pesos ($). This is also the rate that applies to importers. People in general are allowed to buy 200 dollars per month at this rate if they go to a Bank, but no more. But the unofficial dollar rate (what we call de “Blue dollar”) is 1 dollar = 182 AR $. This is what they give you if you go to a currency exchange house (not a Bank) and sell a dollar that you have. These are the rates for today, the 16th of September. Sony, here in my country, is saying that they are selling at the same prices as in the USA. So, at the official exchange rate, this would be, for the 28-60 lens, something as: 500 x 103 = 51.500 AR $. Sony is here selling the 28-60 for 59.000 AR $. Then, 59.000 AR $ / 182 AR $  = 324 US dollars. Therefore, if I sell 324 US dollars that I had saved, they give me 59.000 AR $ with which I can buy the lens. On the other hand, most people that are selling second hand stuff, are willing to recover part of what they paid for a product when the exchange was different and not favourable for buying imported things. Therefore, second hand stuff is not cheap in relation to new stuff nowadays (for how long, nobody knows). Sony, here, is no longer selling the 28-70 lens (at least, not for the time being). Things have not always been the same, and they might change how knows when, so this might be the right time to buy new Sony stuff (if having some savings). These are the reasons why you can’t find in North America the Sony lens at the same amount of money than me, at this particular moment. I know, difficult to understand, it is madness, and can’t last, but for the time being........ So maybe I should buy the Sony 28-60mm lens and have a native AF lens as you say, specially as they are saying it is a good kit lens. Thanks
    • I am not recommending either of the kit lens, the reviews on the web suggest 28-60 is a good lens how much better than 28-70 can't be seen without someone doing a head to head comparison. If you are buying your first native FE lens on a budget, the 28-60 seem like a good option and the price you have quoted for it, I am not seeing it in North America.  I have the 28-70, it was part of an A7II kit (very lightly used) with 3 oem batteries and an oem charger for basically the price of the body on consignment at a local camera store.  I don't use it much but it's always handy to have a native AF lens to grab for quick snapshots when needed.
    • I have added more images to the clearzoom2 page -https://www.rtfract.com/clearzoom2.html  I have also added more details to my special memory page https://www.rtfract.com/smem.html
  • Topics

×
×
  • Create New...