Lens anomalies

Hello

I've just moved from 35mm film photography to digital, so am on a VERY steep learning curve here!

I have a Canon Rebel XSi with the standard kit lens, and also bought the Tamron 11-18mm ultra-wide for landscapes etc.

I was out this morning taking pics, just messing around, changing settings etc, getting used to how the camera operates... too many buttons! :eek:

I was shooting RAW only, the camera set at ISO 100, and when I got home and downloaded my shots I was horrified to see what I can only assume are some kind of lens anomaly/defects in the Tamron lens.

In the first example below the lens was set at f22, which shows up the "smudges," and in the second, taken just seconds later, the lens was set at f11, and it's clear.

I've only ever used Canon and Tamron lens' in the past and have never seen anything like this... can anyone offer any suggestions?

This is particularly worrying for me as I often shoot landscapes at f22 and set the hyperfocal distance for maximum Depth of Field.

Hope you can help!
Paul

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Originally Posted by Paul F

Hello

I've just moved from 35mm film photography to digital, so am on a VERY steep learning curve here!

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I shot film, too. You take an exposure readings, set the ISO, f-stop, and shutter speed, focus, and press the shutter button. Same process. Nothing's changed.

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I was shooting RAW only

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Especially when you shoot RAW only. The camera is not doing any sharpening, color enhancement, noise reduction for you anyhow. So, it is just like shooting film. But, that means, if you want to have a better final photo, you may want to learn to use some photo-processing software. Of course, since you were able to post your photos here and adding those arrows in your pics, you already knew about the pp part.

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This is particularly worrying for me as I often shoot landscapes at f22 and set the hyperfocal distance for maximum Depth of Field.

Hope you can help!
Paul

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Those are dust spots. It means there're dust particles on the sensor of your camera. They show up better when you stop down like at f22. At f11, they're like out of focus/burry and so you don't see them that easily. To deal with them, clean your sensor or clone them out of your image in the post-processing software.

So you just found out one thing that digital photography differs from film photography: dust on the sensor. I mainly used primes when I shot film and so I changed lenses very often. Back then, I never had to worry about dust...or at least it was easy to deal with. Now, whenever you change lens, dust could get onto your sensor. And when you're not careful at cleaning your sensor, you ruin it :p

Welcome to the Forum Paul. Yup, that's dust on your sensor. It's a very common issue, and pretty easy to fix. There are some special sensor cleaning kits you can buy, but I have never used them. All I do to clean my sensor is to us a rocket blower like this one to remove it.

http://www.bhphotovideo.com/c/produc...r_Blower_.html

Don't use the compressed air in a can! If you do a search on the forums for sensor cleaning, you should be able to find some more info on how people do it.

Good luck!

The best way to clean your sensor, and what Canon and olympus often do when you send it in, is to use a SensorSwab (for your camera it's type 2) with a methanol based solution called eclipse. The application is really easy and your sensor ends up really clean. Here's the link

Hi guys, and thanks for the feedback... at least it's not a problem with the lens itself, I was quite worried when I saw the shots.

Gotta love technology, there I was, luxuriating in just blasting through the pics, not having to worry about changing rolls of film etc, and the wonderful world of digital photography brings me, "dust on my sensor;" part of that learning curve I was talking about! :)

And thanks for the links; I've seen the "Rocket Blower" at my local camera store; think I'll try that before I start messing with the sensor itself. I also understand there's a "dust mapping" application, data that can be appended to a photo to get rid of these kinds of effects. Does anyone have any experience with that?

Thanks once again
Paul

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Originally Posted by Paul F

I also understand there's a "dust mapping" application, data that can be appended to a photo to get rid of these kinds of effects. Does anyone have any experience with that?

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I shoot Nikon and they do have something like that but I've never even tried it... Between the Rocket Blower and Dust Aid, I really have no need for it. Be careful when changing lenses, and be sure to keep the lens and body caps clean. Keep the amount of time the camera doesn't have either a lens or body cap on it to the shortest possible, change lenses inside, etc - of course this isn't always possible...

I started using Dust Aid after a few years of being afraid to touch the sensor. A friend uses it and recommended it - glad he did. Good stuff! However, I still use the blower as my first choice but it doesn't seem to get everything off.

I have the "classic" version of Dust Aid, not the newer "wet cleaning" version, btw - apparently it's been discontinued but you might still find it in some shops.

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Originally Posted by another view

I have the "classic" version of Dust Aid, not the newer "wet cleaning" version, btw - apparently it's been discontinued but you might still find it in some shops.

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Thanks for the tips, greatly appreciated! :thumbsup: I took a look at the Dust Aid and they do still have the "dry" version available, in fact, it's been "upgraded" to the Platinum kit, and they still support the "Classic" version with additional strips, but I think only for Canon cameras. Oh, and I'll be picking up one of the Rocket Blowers before the weekend! :)

Paul