How bad is it for the lens if your lens cap comes off inside bag?

Suppose your lens cap slides off after you placed your modern Canon EF lens + body inside your polyester camera bag. How much damage will the lens' front element take from sliding around?

It would depend on several factors. What can it hit as it slides around? I have steel objects like a table clamp in my bag but I don't keep it in the same compartment as a lens. But if I was dumb enough to do so then I would expect significant damage.

How recessed is the front element compared to the rim of the lens. There are lenses where the front element is well recessed; other lenses actually have a front element that protrudes.

In about 55 years of photography, using all sorts of cameras and lenses, I don't think a cap has inadvertently popped off but a half dozen times and never caused any damage. If you consider it a big factor, then join the crowd that protects the lens with a $5 filter.

It's awfully hard to scratch the front element of a lens- the glass is very hard. If you have sand/grit in the bottom of the bag, it could happen.

Leave the hood on the lens, and you won't have any problems.

Let's suppose there isn't anything sharp - only the polyester padded lining typically found in camera bags. Let's also suppose there is minimal sand or grit.

Will the rubbing against the bag or plastic lens cap rub off the multi-coating in the front element?

Jamesino wrote in post #17753651
Let's suppose there isn't anything sharp - only the polyester padded lining typically found in camera bags. Let's also suppose there is minimal sand or grit.

Will the rubbing against the bag or plastic lens cap rub off the multi-coating in the front element?

Let's suppose that you ask a question that we can actually answer?

Jamesino wrote in post #17753630
Suppose your lens cap slides off after you placed your modern Canon EF lens + body inside your polyester camera bag. How much damage will the lens' front element take from sliding around?

Don't know how to answer this one... Put the lens on the camera and take a picture and see if you can see any scratch marks caused by the lens on the image. If there are then the lens is scratched... If not then you'r lens is fine.

Jamesino wrote in post #17753630
Suppose your lens cap slides off after you placed your modern Canon EF lens + body inside your polyester camera bag. How much damage will the lens' front element take from sliding around?

i always have a filter on of some sort, so not an issue for me, except for lenses that can't take filters, like my fisheye.

i've only been shooting for about 4-5 years, so not nearly as long as most here, but i think i've found the cap off in my bag 30+ times or so for various reasons. i do always have my hood on during shooting, but for whatever reason i have found my lens in the bag with the cap off, and without the hood. so it happens, no matter how careful you are. i should note, certain lenses and caps are more prone to this--i haven't had this happen with my newer canon lenses and newer canon caps. most of these accidents were with my efs lenses and old caps.

before this thread becomes a filter vs no filter argument, i'm just going to state that there are scratches on some of my filters. without the filter those scratches would be on the lens. it's that simple. whether those scratches were from the cap falling off, i do not know. probably not. most likely from wiping with my cloth (which i am always careful to crack in the air before use) which inevitably will have contaminates, or sometimes hitting stuff during use. and again, i 100% of the time have the hood on during shooting, so no, the hood doesn't protect from everything. but the hood did save my lenses/filters when the cap came off.

and to answer your question: how much damage from sliding around--probably none. your lens glass is very hard. BUT, you will get scratches eventually if this happens enough.

It's not optimal nor is it likely terrible. Somewhere in between but you can probably tell better than us.

I'd suggest reading this before you get overly worried.

http://www.lensrentals​.com …0/front-element-scratches

Jamesino wrote in post #17753630
Suppose your lens cap slides off after you placed your modern Canon EF lens + body inside your polyester camera bag. How much damage will the lens' front element take from sliding around?

You might be able to scuff the lens coating, but that won't be enough to ruin your IQ. You could cut out a 1 cm x 1 cm square from a postit note and put it on your lens, and not notice it in your shots, just as an example.

TeamSpeed wrote in post #17753936
You might be able to scuff the lens coating, but that won't be enough to ruin your IQ. You could cut out a 1 cm x 1 cm square from a postit note and put it on your lens, and not notice it in your shots, just as an example.

Or you could have a fly inside the lens: http://www.lensrentals​.com …ed-lens-with-a-fly-inside

... And they still couldn't see any difference in the images.

Mike

lens elements are pretty tough...a lot tougher than filters...i'm not quite sure about the question though? did this happen to you? and if so, well what happened? i'd expect usually nothing would happen...it's happened to me, and nothing has happened, that doesn't mean there isn't a chance that your lens could get scratched...as far as how bad it is, well it depends on if anything happens to it...even a scratch isn't going to make a lens useless

so, put the lens cap on the lens...if it comes off, it comes off

Sometimes the outer edges of any given lens element actually falls outside the sensor when projected. That fly is right on the edge of an element, and might actually had zero impact on the image hitting the sensor. Still gross, and one wonders how in the heck that thing ended up so far down inside the lens.

what's a lens cap? those plastic things that come with the lens box? that's where they stay, with the styrofoam.

I purchased screw-on metal covers for all my lenses when I pack for travel. They come off and get stowed somewhere in my bag when I'm shooting.

mcluckie wrote in post #17753979
what's a lens cap? those plastic things that come with the lens box? that's where they stay, with the styrofoam.

I purchased screw-on metal covers for all my lenses when I pack for travel. They come off and get stowed somewhere in my bag when I'm shooting.

I'm curious now, link?