Checking new lens

[Halfmoon]

Hi,

I just like to know what do some things CSer do when buying a new lense...... how you check, etc.....

I check if it is clear, and no dust, and try on the camera to see the focusing..... (mine is film)....

Anything else I should do/ check????

Regards.

 

[candy]

when i send my lenses for servicing, they remove both caps, point it to a light and look through the smaller glass (as if taking a picture).

wat's that about? when i do that all i see is bluuuurrrrrrrr.......

 

[n0d3]

Check for front/back focusing, whether the aperture blades are working fine etc.

 

[clicknick]

when i send my lenses for servicing, they remove both caps, point it to a light and look through the smaller glass (as if taking a picture).

wat's that about? when i do that all i see is bluuuurrrrrrrr.......

Hi, I tried that, and can see a few dust in my lens that I can't normally see. Is it normal to have a few dust in the lens, or are lens suppose to be totally dust free?

 

[espn]

Check for front/back focusing, whether the aperture blades are working fine etc.

That's not so impt actually. Impt stuff includes ensuring the glasses are scratchless, coating is intact, zoom & AF works perfectly. Motor sounds fine.

Hi, I tried that, and can see a few dust in my lens that I can't normally see. Is it normal to have a few dust in the lens, or are lens suppose to be totally dust free?

Dust is everywhere, except clean rooms.

 

[MasterKnight]

That's not so impt actually. Impt stuff includes ensuring the glasses are scratchless, coating is intact, zoom & AF works perfectly. Motor sounds fine.

Pardon me for asking this, how do you you know whether the coating is intact or not? Feel it or any other sign of coat being present? Thanks.

 

[espn]

If there's scratches, the coating will show, the 'colours' on the glass will be smudged.

 

[MasterKnight]

If there's scratches, the coating will show, the 'colours' on the glass will be smudged.

Thanks for your reply. Sorry to hijack this thread. I am just curious about coating as I notice some 'flakes' when I clean my lens, could it be that I have 'damaged' the lens coating?

 

[espn]

See if the flakes are persistent, Ian did a post on creating a cleaning solution for glasses, check it out

 

[MasterKnight]

See if the flakes are persistent, Ian did a post on creating a cleaning solution for glasses, check it out

Could you post the link to that? Thanks.

 

[espn]

http://forums.clubsnap.org/search.php?searchid=1881048

 

[MasterKnight]

Thanks! :cheers:

 

[Halfmoon]

Check for front/back focusing, whether the aperture blades are working fine etc.

Sorry... what do you mean by front and back focusing????

I am using Canon camera, and the lens do not have aperature setting, so how do I go about it???

Thanks.

 

[n0d3]

Sorry... what do you mean by front and back focusing????

I am using Canon camera, and the lens do not have aperature setting, so how do I go about it???

Thanks.

Search back/front focusing on the forums/Google. What camera are you using? Just put your camera in Av mode and hold the depth of field preview button while changing the aperture.

 

[BlueFly]

Aside from the physical checks, it is important to take some test shots. Even highly regarded lens from Nikon or Canon, et al have manufacturing issues and a lemon or two that escaped quality control.

I therefore avoid buying on the web or from foreign countries on my trips abroad. Not worth the hassle if I end up with a lemon.

Hence for expensive lenses I prefer to buy from my local dealer; that way if I have any issues with the purchase I can bring it back for an exchange.

cheers

 

[Halfmoon]

Thanks for all the replies.

I really appreciate the advices.

 

[Halfmoon]

Search back/front focusing on the forums/Google. What camera are you using? Just put your camera in Av mode and hold the depth of field preview button while changing the aperture.

I am using Canon 300X, film camera. So I just use the depth of field preview button right???

 

[Firefox]

I am using Canon 300X, film camera. So I just use the depth of field preview button right???

Yes..

Afterwhich, you can stop down to minimum aperture (usually F22) and remove the lense while depressing the dof preview button. This will lock the aperture blades in place and you can inspect the blades for oil..

Don't worry, the blades won't be stuck. Simply replace the lense onto the body and the blades will move out to wide open again. It happens even if your camera is in 'L' mode.

 

[adamadam]

I heard to also check the screws at the back to see if they have been unscrewed/opened before.
but the reason of this I am unsure of.

 

[Adam Goi]

Hi.

Take a friend with you ... make sure he/she is knowledgeable in this subject area ...