Bought a open-box lens, how do i test it?

[IvankoPetro]

Purchased E PZ 18-105mm F4 G OSS open box, seller said that its new lens just seals from box removed.

As i received lens it has little dust outside near the front glass and signs of it being mounted to camera before (camera mount has few scratches).

Overall lens exterior looks like a new, not a single scratch or mark on the body of lens, but could be that they used some kind of protector because by amount of dust around the front element it looks like was out of the box for quite a while.

Could be that that they used it and did not like something about it then decided to sell it, how do i test optical characteristics of the lens to make sure its really good as new internally?

Motor operates smoothly and zoom-in/zoom-out good at slow speed, but when i push the zoom button all the way motor is louder than on minimal speed guess that's normal.

 

[ahaslett]

Start by looking at two or more reviews of the lens to set your expectations. Then do test shots at various focal lengths, subject distances and apertures.

I like ProfHankD’s point spread function test as a quick check of centering, LoCA and SA. It also shows up cut bokeh etc, if you move the LEDs around the frame.

https://www.pentaxforums.com/forums...iscussion/81530-lens-bokeh-research-help.html

I also shoot the barcode on the lens box at an angle to visualise LoCA.

I find brick wall tests work quite well, if you have a nice textured brick with colours. Checking focus by MF at the centre and each corner, gives insight into field curvature and tilt.

Since my primary subject is landscape, I like to see images across the centre of the frame and their consistency of rendering. These are all test shots. I’ll spare you the brick walls - not exactly thrilling.

This visualises both.

I also take lots of test images of different subjects, looking for the effects of flare, veiling glare, vignetting, SA, weird bokeh etc.

My favourite rendering test is light shining off ivy leaves.

You will also be checking for AF speed and consistency, any mechanical issues with zoom, and how easy it is to use MF (the 100-400 GM is so bad as to be unusable).

Hope that helps.

Andrew

--
Infinite are the arguments of mages. Truth is a jewel with many facets. Ursula K LeGuin
Please feel free to edit any images that I post

 

[IvankoPetro]

Start by looking at two or more reviews of the lens to set your expectations. Then do test shots at various focal lengths, subject distances and apertures.

I like ProfHankD’s point spread function test as a quick check of centering, LoCA and SA. It also shows up cut bokeh etc, if you move the LEDs around the frame.

https://www.pentaxforums.com/forums...iscussion/81530-lens-bokeh-research-help.html

I been into photography for five years, but this particular thing feels too technical for me, feel like rocket science.

I also shoot the barcode on the lens box at an angle to visualise LoCA.

That one thing i never cared about only seen this in one review on youtube who checks for this, why even bother? Chromatic aberrations are correctable with couple clicks.

I find brick wall tests work quite well, if you have a nice textured brick with colours. Checking focus by MF at the centre and each corner, gives insight into field curvature and tilt.

I always found brick walls less than ideal standing too close give very little DoF and difficult to put camera parallel to the wall to take perfect photo. Maybe it jut me, but handheld brick wall photo never worked for me.

Curvature also other characteristics of lens are known from reviews i just need to test my particular lens to be within specs. Not much can be done about bokeh either.

 

[ahaslett]

Start by looking at two or more reviews of the lens to set your expectations. Then do test shots at various focal lengths, subject distances and apertures.

I like ProfHankD’s point spread function test as a quick check of centering, LoCA and SA. It also shows up cut bokeh etc, if you move the LEDs around the frame.

https://www.pentaxforums.com/forums...iscussion/81530-lens-bokeh-research-help.html

I been into photography for five years, but this particular thing feels too technical for me, feel like rocket science.

Just take lots of pictures then. How is shooting an out of focus LED light “rocket science”.

I also shoot the barcode on the lens box at an angle to visualise LoCA.

That one thing i never cared about only seen this in one review on youtube who checks for this, why even bother? Chromatic aberrations are correctable with couple clicks.

That’s LaCA, not LoCA.

I find brick wall tests work quite well, if you have a nice textured brick with colours. Checking focus by MF at the centre and each corner, gives insight into field curvature and tilt.

I always found brick walls less than ideal standing too close give very little DoF and difficult to put camera parallel to the wall to take perfect photo. Maybe it jut me, but handheld brick wall photo never worked for me.

You need to use a tripod.

Curvature also other characteristics of lens are known from reviews i just need to test my particular lens to be within specs. Not much can be done about bokeh either.

Many, indeed most reviews don’t discuss field curvature. The tests also show tilt.

Andrew

 

[Impulses]

Start by looking at two or more reviews of the lens to set your expectations. Then do test shots at various focal lengths, subject distances and apertures.

I like ProfHankD’s point spread function test as a quick check of centering, LoCA and SA. It also shows up cut bokeh etc, if you move the LEDs around the frame.

https://www.pentaxforums.com/forums...iscussion/81530-lens-bokeh-research-help.html

I been into photography for five years, but this particular thing feels too technical for me, feel like rocket science.

To me it actually seemed like a very reasonable answer to the question you asked... Here's another approach (personally I think it can be done just fine handheld and that's part of the simplicity to it):

How to check how decentered your lens is - phillipreeve.net

How to check if your lens is decentered? You may have already heard of sample variation or decentered lenses. In this article we will show you how to easily test your lenses for proper centering. If you know how it works it will take you less than 5 minutes per lens! Where this test originates …...

phillipreeve.net

Most other tests based around charts and what have you are even more technical and easier to mess up, or will just turn into a wild goose chase (because they're easy to mess up).

I also shoot the barcode on the lens box at an angle to visualise LoCA.

That one thing i never cared about only seen this in one review on youtube who checks for this, why even bother? Chromatic aberrations are correctable with couple clicks.

You might be confusing LaCA with LoCA. Practically every serious lens review tests for both so I'm not sure what reviews you're perusing.

I find brick wall tests work quite well, if you have a nice textured brick with colours. Checking focus by MF at the centre and each corner, gives insight into field curvature and tilt.

I always found brick walls less than ideal standing too close give very little DoF and difficult to put camera parallel to the wall to take perfect photo. Maybe it jut me, but handheld brick wall photo never worked for me.

That's fair, that's what makes the four corners test or the upside down variant easier to execute since the scene is ideally at infinity and you don't have to worry about perfectly aligning things.

Curvature also other characteristics of lens are known from reviews

Very few reviews actually test for field curvature, it is not the same thing as geometric distortion.

i just need to test my particular lens to be within specs. Not much can be done about bokeh either.

You can always just shoot with it, "within spec" can be a pretty broad definition.

 

[IvankoPetro]

https://phillipreeve.net/blog/how-to-check-how-decentered-your-lens-is/

Most other tests based around charts and what have you are even more technical and easier to mess up, or will just turn into a wild goose chase (because they're easy to mess up).

Yes this is similar to article i've read few years ago, but lost since, very good info will try that.

Problem with the PSR "point spread function" its not from photography field, its from physics optometry whatever technical field that has little to do with actual photography. i have no idea about it and it does not look like something i do every day or need to do its like steep learning curve for something that has little to do with way i use camera. Other approach with actually taking photos is more intuitive for me.

 

[daran]

Purchased E PZ 18-105mm F4 G OSS open box, seller said that its new lens just seals from box removed.

As i received lens it has little dust outside near the front glass and signs of it being mounted to camera before (camera mount has few scratches).
Overall lens exterior looks like a new, not a single scratch or mark on the body of lens, but could be that they used some kind of protector because by amount of dust around the front element it looks like was out of the box for quite a while.

Could be that that they used it and did not like something about it then decided to sell it, how do i test optical characteristics of the lens to make sure its really good as new internally?

The usual way is to take photos at the corners of the sensor and compare them. If there is any tilt in the lens it will show up. Be warned that this test is pretty sensitive and even very good lenses may show a bit of disparity. Details how to do this are here: https://www.fredmiranda.com/forum/topic/1534737/0

 

[IvankoPetro]

Purchased E PZ 18-105mm F4 G OSS open box, seller said that its new lens just seals from box removed.

As i received lens it has little dust outside near the front glass and signs of it being mounted to camera before (camera mount has few scratches).
Overall lens exterior looks like a new, not a single scratch or mark on the body of lens, but could be that they used some kind of protector because by amount of dust around the front element it looks like was out of the box for quite a while.

Could be that that they used it and did not like something about it then decided to sell it, how do i test optical characteristics of the lens to make sure its really good as new internally?

The usual way is to take photos at the corners of the sensor and compare them. If there is any tilt in the lens it will show up. Be warned that this test is pretty sensitive and even very good lenses may show a bit of disparity. Details how to do this are here: https://www.fredmiranda.com/forum/topic/1534737/0

This method has any advantages vs this method?

I tried both and turning camera upside down and tilting it 45 degree is way more difficult especially on tripod.

 

[daran]

Purchased E PZ 18-105mm F4 G OSS open box, seller said that its new lens just seals from box removed.

As i received lens it has little dust outside near the front glass and signs of it being mounted to camera before (camera mount has few scratches).
Overall lens exterior looks like a new, not a single scratch or mark on the body of lens, but could be that they used some kind of protector because by amount of dust around the front element it looks like was out of the box for quite a while.

Could be that that they used it and did not like something about it then decided to sell it, how do i test optical characteristics of the lens to make sure its really good as new internally?

The usual way is to take photos at the corners of the sensor and compare them. If there is any tilt in the lens it will show up. Be warned that this test is pretty sensitive and even very good lenses may show a bit of disparity. Details how to do this are here: https://www.fredmiranda.com/forum/topic/1534737/0

This method has any advantages vs this method?
I tried both and turning camera upside down and tilting it 45 degree is way more difficult especially on tripod.

Roughly the same unless there is flex in your camera&lens combo. To just get a rough impression either will do.

 

[IvankoPetro]

test

Explore this photo album by Roman Est on Flickr!

www.flickr.com

Got to look at full size and look at 100% zoom, than this i presume either focus issue or motion blur because i overly estimated OIS and kept shutter speed lower.

Used auto-focus on center point for all images.

I am surprised how out of focus wooden rabbit is, i focused on him in the center of frame (half way click), moved to camera then full click and still he's out of focus or is it motion blur?

Also same for yellow buldožer on the beach (last photo) if you look 100% at tree and buldozer they are blurred and i auto focused on the dozer then moved and took shot.



Please don't tell me this lens is supposed to be so soft because i have some photos that are sharp and in focus.

 

[Impulses]

https://phillipreeve.net/blog/how-to-check-how-decentered-your-lens-is/

Most other tests based around charts and what have you are even more technical and easier to mess up, or will just turn into a wild goose chase (because they're easy to mess up).

Yes this is similar to article i've read few years ago, but lost since, very good info will try that.

Problem with the PSR "point spread function" its not from photography field, its from physics optometry whatever technical field that has little to do with actual photography. i have no idea about it and it does not look like something i do every day or need to do its like steep learning curve for something that has little to do with way i use camera. Other approach with actually taking photos is more intuitive for me.

It's not that hard to do once you actually understand it, I wouldn't let the name deter you, looking at the way the bokeh behaves can be a very good test for centering and alignment issues.

 

[Impulses]

Purchased E PZ 18-105mm F4 G OSS open box, seller said that its new lens just seals from box removed.

As i received lens it has little dust outside near the front glass and signs of it being mounted to camera before (camera mount has few scratches).
Overall lens exterior looks like a new, not a single scratch or mark on the body of lens, but could be that they used some kind of protector because by amount of dust around the front element it looks like was out of the box for quite a while.

Could be that that they used it and did not like something about it then decided to sell it, how do i test optical characteristics of the lens to make sure its really good as new internally?

The usual way is to take photos at the corners of the sensor and compare them. If there is any tilt in the lens it will show up. Be warned that this test is pretty sensitive and even very good lenses may show a bit of disparity. Details how to do this are here: https://www.fredmiranda.com/forum/topic/1534737/0

This method has any advantages vs this method?
I tried both and turning camera upside down and tilting it 45 degree is way more difficult especially on tripod.

I find the corners easier to do with a long FL and the upside down approach easier to do with wide FLs, YMMV.

 

[IvankoPetro]

To me it actually seemed like a very reasonable answer to the question you asked... Here's another approach (personally I think it can be done just fine handheld and that's part of the simplicity to it):

https://phillipreeve.net/blog/how-to-check-how-decentered-your-lens-is/

Front curtain shutter - off
Steady Shot - off
Manual Focus

Distance to tower 850 meters (0.5miles) to me i see no de-centering, perhaps need to select more detailed object closer because on 18mm its very soft even in center of frame.



Also on 53mm both lower images look softer could be also de-centered slightly vertically?

18mm F/4 Very soft

53mm F/4

105mm F/4

 

[Impulses]

To me it actually seemed like a very reasonable answer to the question you asked... Here's another approach (personally I think it can be done just fine handheld and that's part of the simplicity to it):

https://phillipreeve.net/blog/how-to-check-how-decentered-your-lens-is/

Front curtain shutter - off

I'd keep it on tbh to avoid any potential shutter shock (which can cause softness if the SS is slower) but it's probably not a big deal.

Steady Shot - off
Manual Focus

Distance to tower 850 meters (0.5miles) to me i see no de-centering, perhaps need to select more detailed object closer because on 18mm its very soft even in center of frame.

Remember, some softness is fine (it's a super zoom after all, it's expected wide open), it's when one corner or side ends up looking much more soft than the other that you could have a sample issue. With wide angles it might be easier to just do the right side up + upside down version of the test.

Also on 53mm both lower images look softer could be also de-centered slightly vertically?

Yeah maybe, I've seen much worse though.

18mm F/4 Very soft

53mm F/4

105mm F/4

I'd probably just re-run the test at 18mm either stopped down a bit and/or just to compare one right side up frame with an upside down one.

 

[ahaslett]

To me it actually seemed like a very reasonable answer to the question you asked... Here's another approach (personally I think it can be done just fine handheld and that's part of the simplicity to it):

https://phillipreeve.net/blog/how-to-check-how-decentered-your-lens-is/

Front curtain shutter - off

I'd keep it on tbh to avoid any potential shutter shock (which can cause softness if the SS is slower) but it's probably not a big deal.

Steady Shot - off
Manual Focus

Distance to tower 850 meters (0.5miles) to me i see no de-centering, perhaps need to select more detailed object closer because on 18mm its very soft even in center of frame.

Remember, some softness is fine (it's a super zoom after all, it's expected wide open), it's when one corner or side ends up looking much more soft than the other that you could have a sample issue. With wide angles it might be easier to just do the right side up + upside down version of the test.

Also on 53mm both lower images look softer could be also de-centered slightly vertically?

Yeah maybe, I've seen much worse though.

18mm F/4 Very soft

53mm F/4

105mm F/4

I'd probably just re-run the test at 18mm either stopped down a bit and/or just to compare one right side up frame with an upside down one.

I'd be definitive that this lens does not suffer from decentering or tilt to any significant extent, certainly well within the bounds of copy variation.

I've been looking at the limited reviews of the lens and sample images. It isn't a high performer, which is typical for a superzoom. The images above don't look too bad to me, so I'm slightly puzzled why the images in another post by OP are so soft.

I've shot a lot with 16Mpix MFT bodies and use several kit lenses. I'm used to processing from RAW a little more aggressively with kit lenses. I've never seen anything quite as soft as the sample images. There is no obvious explanation, although the very high shutter speeds at low ISO look a bit odd in some of the images.

Maybe we could help OP get to the bottom of this?

Andrew

--
Infinite are the arguments of mages. Truth is a jewel with many facets. Ursula K LeGuin
Please feel free to edit any images that I post

 

[IvankoPetro]

Remember, some softness is fine (it's a super zoom after all, it's expected wide open)

Do you mean supposed to be soft at wide apertures or when at wide angles like 18mm, because in my opinion its super soft at 18mm for some reason well i tested only at F4 so far, will compare F8 also.

I'd probably just re-run the test at 18mm either stopped down a bit and/or just to compare one right side up frame with an upside down one.

I did run the upside down diagonal test, but i did it incorrectly so have to do it over.
So far i have this new test results using regular method.

• Distance to object 75 meters (80 yards)
• Front Curtain Shutter - Off
• Optical stabilization - Off
• Manual Focus

18mm F/4

53mm F/4

105mm F/4

• Distance to object 65 meters (70 yards)

18mm F/4

53mm F/4

105mm F/4

Source images are here: https://www.flickr.com/photos/191857049@N08/albums/72177720325082066

Just realized that being so close to the subject or having subject that is big (big letters/symbols) is like testing on test chart that is not have very fine details, for most precise test need to focus as far as possible like i did in the first test. Will repeat that tomorrow.

 

[IvankoPetro]

I've been looking at the limited reviews of the lens and sample images. It isn't a high performer, which is typical for a superzoom. The images above don't look too bad to me, so I'm slightly puzzled why the images in another post by OP are so soft.

I've shot a lot with 16Mpix MFT bodies and use several kit lenses. I'm used to processing from RAW a little more aggressively with kit lenses. I've never seen anything quite as soft as the sample images. There is no obvious explanation, although the very high shutter speeds at low ISO look a bit odd in some of the images.

Maybe we could help OP get to the bottom of this?

I think i figure out what the problem was, its user error.

1st this lens is so easy to jump from wide to telephoto without any noticeable changed in brightness since its F/4, so like first i take test video at 1/50s then i take photo sometimes same low shutter speed, and i was over relaying on OIS even though i put F8 i kept ISO 100-200 the most on the first test so shutter speeds were too slow perhaps my hands move a lot and i should have used at least 1/200-400s when at 105mm focal.

Now i did second test in the same place keeping the shutter speed minimum 1/1000s and photos looks much sharper, not sure if the OIS in the lens might be faulty or my hands are too shaky, for video OIS seems like working good.

2nd flaw i treated lens as parfocal lens so sometimes i adjust framing after AF lock, which was mistake as this lens is not parfocal.

3rd problem i described here.

 

[ahaslett]

I've been looking at the limited reviews of the lens and sample images. It isn't a high performer, which is typical for a superzoom. The images above don't look too bad to me, so I'm slightly puzzled why the images in another post by OP are so soft.

I've shot a lot with 16Mpix MFT bodies and use several kit lenses. I'm used to processing from RAW a little more aggressively with kit lenses. I've never seen anything quite as soft as the sample images. There is no obvious explanation, although the very high shutter speeds at low ISO look a bit odd in some of the images.

Maybe we could help OP get to the bottom of this?

I think i figure out what the problem was, its user error.

1st this lens is so easy to jump from wide to telephoto without any noticeable changed in brightness since its F/4, so like first i take test video at 1/50s then i take photo sometimes same low shutter speed, and i was over relaying on OIS even though i put F8 i kept ISO 100-200 the most on the first test so shutter speeds were too slow perhaps my hands move a lot and i should have used at least 1/200-400s when at 105mm focal.

Now i did second test in the same place keeping the shutter speed minimum 1/1000s and photos looks much sharper, not sure if the OIS in the lens might be faulty or my hands are too shaky, for video OIS seems like working good.

2nd flaw i treated lens as parfocal lens so sometimes i adjust framing after AF lock, which was mistake as this lens is not parfocal.

3rd problem i described here.

With 16Mpix, you should be fine with decent holding technique at 1/f*1.5, so 100mm should be OK at 1/150s. In any case isn’t that an OSS lens, so you should do quite a bit better with Steadyshot on?

Are you shooting RAW and processing? I ask because some of the shots at high shutter speeds look like noise reduction is smoothing details.

Sounds like you are making progress.

Andrew

 

[IvankoPetro]

With 16Mpix, you should be fine with decent holding technique at 1/f*1.5, so 100mm should be OK at 1/150s. In any case isn’t that an OSS lens, so you should do quite a bit better with Steadyshot on?

Actually i had another manual zoom 55-200mm (weight 600 grams) when i use it (without any stabilization) by trial and error i got to minimal shutter speed 1/400s at max zoom level.

Perhaps with this OIS i could use lower speeds to 1/125/s for 105mm to be safe because even though i use neck strap for extra stabilization.

Similar to this, however i try not to hold the end of the lens to avoid tripping the focal length wheel or button

NEX-5T is too small and light (270 grams) and dis-balanced as lens weight almost twice more (430g) than camera.

Are you shooting RAW and processing? I ask because some of the shots at high shutter speeds look like noise reduction is smoothing details.

It was JPG from camera, was lazy to develop RAW. First test i did not shoot at high ISO so did not notice much noise reduction going on. However i did set creative style in camera

• Cotrast -3
• Saturatio 0
• Sharpness -3

i even thought that it could be adding blur because of sharpness -3, but compared JPG and RAW and did not notice any more blur.

Did a AF test it pass good, had to use battery because camera has problem focusing on the black line.

18mm

25mm

53mm

105mm

 

[BubbaBob]

Take pictures.