DSLR cleaning

[Mr. Quebec]

Hi!

I was thinking on the subject, and I thought that this might be a good topic to discuss. I don’t have any problems, (except a few dust particles I would like to get rid of on my mirror), but I thought that maybe we could develop the subject.
For cleaning my sensor, I lift up the mirror, take off the lens, hold my DSLR body face down, and blow air with a little air blower. I am wondering if the dust particles or whatever that is blown away would be just blown somewhere else in the camera and cause problems.
I would like to know if there are other methods or a few details that would do a better job…
And about the mirror, is it okay to take a microfiber cloth and clean it gently, or is a part that I should not touch?
Thanks.

[Ezra Morley]

I don’t think I would touch the mirror, but that’s just me. I know how annoying it is though to see dark spots when you look through your viewfinder. 🙁

I used a Rocket Blower to clean my sensor just as you said you do. I’ve had pretty good results with that.

I’ve heard of using cleaning kits such as this with swabs to clean the sensor/mirror. I have never actually used one, so I can’t tell you how it would work. Just be very careful!

[James Staddon]

This is a great topic, @Mr-Quebec!

I touch on this subject in the Foundations Course on the lesson about Choosing the Right Accessories. That’s where I list the items that I use and have found to be integral to keeping my sensor clean.

When I clean the sensor, I generally mount the camera facing downward on a tripod, with me pointing the Rocket blower up as I blow off the sensor, like you said.

I also do not have a problem with wiping the mirror with my Sensor-Brush or SensorWand. I like having my viewfinder clean if possible.

And as for blowing vs wiping the sensor? Blowing is a good way to start. I do both if it’s needed. The last time I cleaned my sensor, it really needed to be wiped with the Sensor-Brush.

This is a 1:1 crop of what I started with; it’s the top left corner of my sensor with no cleaning at all:

This is what it looked like after blowing it a few times. It took care of the dust, but not the spots. And I think it’s interesting that it moved some of the spots around.

This is what it looked like after wiping it one time with the Sensor-Brush. To me, this is more what I’m going for. It’s interesting that it moved around some of the spots and added a few more. That’s a good thing though, because that means the spots aren’t adhered to the sensor.

This is what it looked like after wiping it a second time. I do as few wipes as possible, so I figured it was good enough, even though there was still one new spot left.

• This reply was modified 54 years, 9 months ago by .

[Mr. Quebec]

Thanks, everybody!

I have another question, which probably doesn’t relate to DSLR cleaning. My 7D viewfinder seems to have a vignette when I zoom to about 200-300mm. It has a grainy look overall, and the sides seem to darken when I zoom. Does this means a dirty viewfinder?
What makes me hesitant to make that assumption is that when I take the battery off, the viewfinder become very dark and grainy, and when I put the battery back again, everything is normal. Also, when I set my camera on ”spot” metering, the viewfinder now has a circle in the middle of my viewfinder. Is it possible that 7Ds use a different viewfinder system than the T3s? Or is it just because the viewfinder is dirty? Or a lens problem?

[Ezra Morley]

Oh boy, now you’re getting into some technical questions here! 🙂

First, the vignetting and grain: Cheap (or even some more expensive) telephoto zoom lenses have a maximum aperture of f/5.6 at the 200-300mm end of the focal range. A typical lens will be something like this: 70-300mm f/3.5-5.6 That means that at the “wide” end (70mm), the widest aperture is f/3.5, and the at the “long” end, (300mm) the widest aperture is f/5.6

So,when you zoom in, the aperture “stops down” automatically to f/5.6, which in turn, darkens the viewfinder. That’s one reason why people like (and pay big $$ for) f/4 or even f/2.8 zoom lenses. The wider the aperture, the brighter the viewfinder. (To a point… If you go too wide, like f/1.4 or f/1.2, the camera probably stops it down a little so that the AF can find something to focus on, but that’s a whole different topic.) [There are many other reasons to buy a “fast” zoom lens too, the image quality is usually much better, and the background can be blurred more with a wider aperture]

If you really want to see the viewfinder get dark, set your aperture to f/16 or f/22, then hit the DOF preview button while looking through your viewfinder!

Vignetting is also to be expected from cheap zooms, although I don’t know if I’ve ever actually seen it through the viewfinder! I wouldn’t worry about it, unless you’re getting visible vignetting in your photos as well.

Now, to the dark and grainy VF when you remove the battery…

I knew that Canon’s more modern cameras had a so-called “Intelligent Viewfinder”, but I didn’t realize that the 7D had it; I would have guessed that it was too old to have that technology! Anyway, Canon came up with some sort of electronic wizardry that allows them to overlay various grids, AF points, and other info over the viewfinder. Most of it is customizable, so you can select what all you want to see, (or not see). But to do that, they messed with the viewfinder so that it has to have a little bit of electric power from the battery to work properly. So when you remove the battery, all of a sudden your OVF (Optical View Finder) doesn’t look as pretty any more! It’s nothing to worry about, unless you like to take pictures without a battery in the camera. 🙂

Here’s what Canon has to say about it: Canon DLC | An overview of the Intelligent Viewfinder Display system

The LCD overlay does require a tiny amount of electrical power to operate. This is obviously no concern when the camera is turned on, but if the battery is removed the transmissive LCD suddenly loses a lot of brightness and contrast. This is perfectly normal and will return to full brightness once a battery is reinstalled in the camera (the camera doesn’t have to be turned on; it only requires a functioning battery pack to draw power for proper viewfinder operation).

BTW, the “Intelligent Viewfinder” is also responsible for the little circle that you see in the viewfinder when your camera is set to “Spot Metering”. That’s to let you know that the camera is set to that mode.

Yes, the 7D’s viewfinder is much superior to the T3’s VF. It’s bigger, brighter, has more magnification, and 100% coverage. Quite a list of improvements! That’s one of the differences between an entry-level camera (T3/5/6), and the more professional 7D series.

One more thing. If you think the 7D’s Intelligent Viewfinder is something, you should check out the new 7D MK II’s VF! It has a whole lot more “wizardy” going on, with lots more info that can be displayed!

[Mr. Quebec]

Wow! Great information there, @buddingphotographer!

So,when you zoom in, the aperture “stops down” automatically to f/5.6, which in turn, darkens the viewfinder.

I should have thought of that one! But I’ve heard that the VF is alreardy set at f/5.6. (Maybe I get everything confused…) When I snap a picture at f/1.8 or f/2, the background in the picture is more soft than in my viewfinder.
So, could it be possible that the aperture in the 7D’s VF is bigger than f/5.6?

BTW, it’s amazing how much info can be displayed in the 7D Mark II’s viewfinder. You can know most of the information in the viewfinder instead of looking on the top LCD!

• This reply was modified 54 years, 9 months ago by .

[Ezra Morley]

I should have thought of that one! But I’ve heard that the VF is alreardy set at f/5.6. (Maybe I get everything confused…) When I snap a picture at f/1.8 or f/2, the background in the picture is more soft than in my viewfinder.
So, could it be possible that the aperture in the 7D’s VF is bigger than f/5.6?

Yeah, that’s why I said what I did earlier 🙂

The wider the aperture, the brighter the viewfinder. (To a point… If you go too wide, like f/1.4 or f/1.2, the camera probably stops it down a little so that the AF can find something to focus on, but that’s a whole different topic.)

I’m not exactly sure what is happening behind the scenes, especially with the modern, electronically controlled apertures. I’m sure it even varies between camera manufacturers, I don’t know much about Canon, since I’m now using Pentax. I know that my Pentax does stop down some when in Live View, but I haven’t tested to see what exactly it is that triggers it. My camera has been stuck in Manual Mode for a couple of months now, so since it’s not doing the metering for me any more, it doesn’t really matter whether it stops down or not! 🙂

I did some research on the subject, and so far, every source I’ve seen says that Canon lenses are wide-open until you actually trip the shutter. So a 50mm f/1.8 will be brighter than a 50mm f/2.8. (So a cheapo 70-300 f/5.6 is like night, compared to the 50mm f/1.2!)

The 7D’s (or any other camera’s) viewfinder does not have an aperture, (i.e. it’s not set at f/5.6) The aperture is inside of the lens, and the viewfinder only sees whatever the lens “shows” it. 🙂

I think you were thinking about focus point sensitivity. The 7D cannot focus with any lens that is “slower” than f/5.6. So if you have a lens whose maximum aperture is higher than f/5.6 (like f/8 or f/11), your camera won’t be able to autofocus, it’s just too dark to be reliable. Newer cameras are getting better at this, Canon’s newest 1D X II can autofocus with all of it’s focus points at f/8!

Here’s an in-depth look at Canon’s AF system if you’re interested: http://www.the-digital-picture.com/Photography-Tips/Canon-EOS-DSLR-Autofocus-Explained.aspx

[Mr. Quebec]

I did some research on the subject, and so far, every source I’ve seen says that Canon lenses are wide-open until you actually trip the shutter. So a 50mm f/1.8 will be brighter than a 50mm f/2.8.

I’m sorry, but I’m really getting mixed up. I’ve tried my 50mm 1.8 and played with my DOF preview button. I can’t hear nothing at f/1.8, but when I rise the aperture, I can hear the aperture engaging in my lens. Also, I can see the viewfinder only darkening at f/3.2. So I guess that f/2.8 is the limit for the viewfinder for focusing. It’s quite obvious that my lens is wide-open, but at the same time, I’m pretty sure that my viewfinder isn’t at f/1.8, because my pictures at f/1.8 are a lot more softer than what I see in my viewfinder.

My technical knowledge is very low, but I’ll have a lot to study with all the links you’ve attached. The link on Canon’s AF looks really interesting 🙂 Thank you so much for your help!

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