[vikranta]

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I recently bought a used SMC DA 35mm Macro lens for my Pentax K5IIs camera. The lens reseller mentioned that the there is coating loss in center element of the lens. Can anyone please explain what that means? Will that affect the photos? Any solutions?

Please let me know. Thanks!!!

[jatrax]

"center element" or "center of element" means two different things. Though in practice neither is a good thing. Usually this means that the coating is chipped or flaking off of the front element usually because it was scratched or impacted.

On older lenses this is not uncommon as the coatings were not as good. On a new lens like the 35mm macro it means (to me) it has been impacted rather severely.

I would not be interested in it at all. Will it impact your pictures? Yes. How much will depend on how big the damaged area is, how deep the scratch and what particular image you are shooting. In soft light it might be unnoticeable, into the sun it might cause a lot of flare and ghosting. But you will not know until you test it.

[vonBaloney]

That would mean that the lens coatings are rubbed off, but I doubt that's actually true. Do you have the lens yet? Are you sure he said "center element" (meaning inside the lens somewhere) or "center of the element" (like the front element). If on the front element, there could be cleaning marks, or actual coating loss. If inside the lens, I would assume it is something else. These modern coatings just don't come off unless they put some sort of horrible solvent on them so in order for that to happen in the "center element" someone would have had to have been inside that lens doing who knows what. (Or more likely it isn't coating loss at all, but some sort of haze or fogging that may or may not come off if you took it apart and cleaned it) So something could have happened to the exposed outer elements I suppose, but my money is still on something other than "coating loss" (unless it is just scratched to hell)...

[osv]

did the seller provide photos of this phenomenon?

have you received the lens yet? if so, shine a flashlight down into the lens from the the big end, at an angle, and bounce the light off of whatever inner elements you can, you should be able to see what the issues really are.

[jatrax]

As to solutions, it is possible to have a lens element re-coated. But I would estimate the cost of doing so would compare closely to the cost of that lens new. It is done occasionally with rare or very expensive lenses but not on relatively inexpensive lenses like the DA 35mm macro.

[vikranta]

"center element" or "center of element" means two different things. Though in practice neither is a good thing. Usually this means that the coating is chipped or flaking off of the front element usually because it was scratched or impacted.

On older lenses this is not uncommon as the coatings were not as good. On a new lens like the 35mm macro it means (to me) it has been impacted rather severely.

I would not be interested in it at all. Will it impact your pictures? Yes. How much will depend on how big the damaged area is, how deep the scratch and what particular image you are shooting. In soft light it might be unnoticeable, into the sun it might cause a lot of flare and ghosting. But you will not know until you test it.

The reseller does mention that there are no scratches or damage to lens and has rated it as very good.. so can the coating can come off even without scratching?

Here is a link to the lens:
SMC Pentax DA 35mm F2 8 Macro Limited Very Good From Japan 03 F64 | eBay

[aleonx3]

Just by merely looking at the photos of the lens on fleabay; it is quite possible the meaning was lost due to translation. It does not look like any coating loss/damage at all. Most used lenses that I found in Japan are very conservatively rated (which means if it is rated good, chances are it is very good). I can't speak for other people, but in Japan, people babies (takes good care of) their camera/lenses.

[kh1234567890]

It is the sticky diaphragm I'd worry about on that one ...

[jatrax]

so can the coating can come off even without scratching?

On older lenses, yes. I have seen it flaking off. But on modern lenses, I don't think so. Those coatings are tough!

I agree with others, maybe something lost in translation. Also note that they list this as a Sigma DC lens. From the pictures I see nothing wrong, but if there is haze internally it is just not worth it. This is a fairly common lens, get a good one.

[vikranta]

I received the lens today. The seller does have a return policy so I can always return if the lens is not alright. Any suggestions on how to test the lens? One was to shine the light using a flashlight through the lens.

Please let me know.

[aleonx3]

I received the lens today. The seller does have a return policy so I can always return if the lens is not alright. Any suggestions on how to test the lens? One was to shine the light using a flashlight through the lens.

Please let me know.

I would do that.. a quick inspection with a flash light into the glass element; check the aperture lever mechanism, visual inspection of the barrel or ring for any damages. Then, I would do a quick focus accuracy test (simplest would be to use 3 AA batteries lined up at 45 degree and focus on the middle one) with aperture at F4, then wide open. You are good to go out and enjoy the "new" used lens.

[vonBaloney]

Shine an LED light through it and look through the other end. If you see a little bit of dust, don't worry about it. Any weird rings or haze should be apparent. If you don't see anything, or even if you do but it is minor (i.e. it is basically clear, and you if you just hold it up to a window or a lamp it looks perfectly clear) then it should be fine.

[vikranta]

I've attached pics of the lens. Do you see a tiny reflection? That is what is different. It is very visible.

What do you think that could be? Something to worry about?

[aleonx3]

It is difficult to tell, when you change the position (rotate) of the lens, does the reflection goes with it too? If it stays relatively in the same position then it is your lighting environment.

[vikranta]

When I rotate the lens the reflection goes with it.