Specs of Dust

Keltic Ice Man

Keltic Ice Man

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Allan
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When I look through the eye piece on my 350D I can see some specs of dust - one is quite large.

I have looked at the photos at 100% and can't see anything on them, I have removed the lens and can still see the specs.

I don't think it is the sensor, and have cleaned the eye piece area is there anywhere else it might be?

Thanks

Allan
 
Underside of the focusing screen. Thats where most crud collects.
If its not on the final image then this is where the beasties are.
Use a blower or very soft (grease free) brush to waft them away... then they can lodge on your sensor :D :shrug:
 
I have that on my 350D, there is nothing on the sensor but I have been told its on the prism which is a pain to clear. Doesn't show up on photos but is annoying
 
oldgit said:
Underside of the focusing screen. Thats where most crud collects.
If its not on the final image then this is where the beasties are.
Use a blower or very soft (grease free) brush to waft them away... then they can lodge on your sensor :D :shrug:
Click to expand...

I know this is a silly question - but how do i get at the underside of the focusing screen? Is this the mirror that you lock up when you clean the sensor?

and is this the same as the Prism or is that a separate part of the camera. (anyone seen a diagram of the inside of a 350D - might be useful so I know what parts do what)
 
I did mine the other day as I had quite a few dots near the autofocus points when looking into my viewfinder.
I removed the lens and looked for the screen with the autofocus points on, and cleaned that.
No dots now.:thumbs:
 
Here...

cam.JPG


Just turn the cam upside down without a lens.. you'll see it.

These screens can be replaced easily for a few quid, if you scratch em, but best to treat em gently ... soft brush or blower.
 
Keltic Ice Man said:
I know this is a silly question - but how do i get at the underside of the focusing screen? Is this the mirror that you lock up when you clean the sensor?
Click to expand...

No. If you remove the lens and look up as far as you can with the mirror in the down position, the focusing screen should just be visible - it forms the roof of the mirror box. On some models it is user removable/replaceable through the lens opening, but unless you have patience and fingers like a piccolo player you can end up putting the screen back a lot messier than you started out. Unless the dust is really bugging you, I'd leave it alone - it has no effect on your pics at all.
and is this the same as the Prism or is that a separate part of the camera. (anyone seen a diagram of the inside of a 350D - might be useful so I know what parts do what)
Click to expand...

It's not the same. The prism sits inside the camera on the other side of the focusing screen - it's why that hump is in the centre of the top plate of the camera. That hump houses the prism. The image which hits your sensor is actually upside down and laterally reversed (back to front). The image which is diverted upwards by the mirror( prior to taking your shot) is bounced off the internal surfaces of the prism several times, being flipped and inverted each time so that the image you actually see in the viewfinder is the right way up and the right way round. Any dust you can see will be on the focusing screen, not the prism.
 
A picture does a 1000 words CT :D
 
oldgit said:
A picture does a 1000 words CT :D
Click to expand...

LOL indeedy

We could actually do with a really good cutaway image showing the path of light through an SLR .
 
CT said:
LOL indeedy

We could actually do with a really good cutaway image showing the path of light through an SLR .
Click to expand...

... I'm hurt... :shake: :(


:razz: :razz: :razz:


:D
 
LOL. No it's ace....really, :lol: but if anyone knows of a proper cutaway view we could use ( or wants to do one) it would help enormously with these sort of threads.
 
Thanks for the diagram - Really useful!!

I've just tried with the blower and a brush, some of the really small bits (looks a bit like a shaving rash :) ) are still there - is it ok to use some eclipse fluid on a pecpad - as I would on my sensor?

or having caught up with CTs reply maybe I leave it for a week or two - but it is a bit annoying
 
Keltic Ice Man said:
Thanks for the diagram - Really useful!!

I've just tried with the blower and a brush, some of the really small bits (looks a bit like a shaving rash :) ) are still there - is it ok to use some eclipse fluid on a pecpad - as I would on my sensor?

or having caught up with CTs reply maybe I leave it for a week or two - but it is a bit annoying
Click to expand...

My honest advice is leave it alone. The screen is squeeky clean on my 1D at the moment, but I have a dust blob on the screen of the 20D which I'm living with. If you use any camera for long enough, you'll get dust, hairs and all sorts of crap on the screen. Have it cleaned by a pro when you absolutely have to. ;)
 
Luminous Landscape to the rescue. Some good cutaway images...

HERE
 
CT said:
LOL. No it's ace....really, :lol: but if anyone knows of a proper cutaway view we could use ( or wants to do one) it would help enormously with these sort of threads.
Click to expand...

If we are going to disect a camera could we do it to a Nikon then?:lol: :D

:naughty:
 
Keltic Ice Man said:
What sort of price does it cost to get a professional clean? How often ? and where?

Thanks

And the picture of the camera has really helped show me whats under the bonnet
Click to expand...

I have no idea how much Canon would charge. Have a look in Yellow Pages though you might find someone local, and many of these independent repairers have had fiull factory training from the big makers.

I have a local guy who unfortunately has been badly hit by the swing to digital. He's closed his shop and now works from home. Due to the increasing complexity of digital cameras he can no longer undertake repairs to them, but things like cleaning the screen are just the same as film cameras, and would probably be done in minutes while you wait.
 
CT said:
LOL indeedy

We could actually do with a really good cutaway image showing the path of light through an SLR .
Click to expand...


Do you want this guys? ...I will finish it for us :D
... What else would be useful on it?
tpcameracutough.png


I can put on an aperture diaphragm, and a shutter bit, kind of: thinking: ... Sensor sizes and 35mm sizes to explain the crop factor thing. :thinking:

Anything else?

I don’t have to be super accurate or anything does it? …guidance with the details would be good too?

If you do want this finished guys… perhaps we can me it a joint effort :) ....because what I'd really like to do is super impose the finished image onto a side shot of a DSLR ... But I only have one camera in the house so I can't take the shot. :shrug:

I need a super crisp side image very square-on, against a black or dark back ground of a black DSLR... with a 50mm on or similar length.

I'd prefer a Nikon But I guess I Cannon will do.
 
I can do you a Canon this evening so long as its not too far beneath your requirements..........:D
 
Top job Adam... that's really excellent. :thumbs:

Showing the position of the diaphragm, shutter and sensor would probably be useful additions. :)
 
Keltic Ice Man said:
What sort of price does it cost to get a professional clean? How often ? and where?

Thanks

And the picture of the camera has really helped show me whats under the bonnet
Click to expand...

I believe around £30. Check the manual or your camera box as it tells you where the Canon dealerships are in your area.

It's actually very easy to do. I used the same eclipse fluid and pec pad that I use to clean the sensor. Turn the camera upside down and it only takes a swipe or two and you'll have a nice, brighter and clean viewfinder.

You'll be surprised just how easy it is.
 
Keltic Ice Man said:
What sort of price does it cost to get a professional clean? How often ? and where?

Thanks

And the picture of the camera has really helped show me whats under the bonnet
Click to expand...

Similar to previous post... I just use my ArcticButterfly (staticy brush wotsit).... nice and clean :)
 
i read this post and thought i'll have a go,(big chunk of dust in veiwfinder)
first i cleaned the work area, waited for dust to settle.
dusted the camera so no stray dust would fall when dismantling
prepaired my swabs,
took lens off,
removed focusing screen (5D)
use puffer on pentaprism,
cleaned focusing screen with swab with a drop of eclipes
replaced screen,
clicked mirror up, used puffer on sensor,
then used new swab with a drop of eclipes to clean sensor,
drop mirror and check using the F22 method
worked a treat for me, big chunk of dust gone and sensor clean.
 
Forbiddenbiker said:
... Sould it be a white background....blacks a bit , well black, too black for TP ...? :thinking:
Click to expand...

I'll do a selection Adam - give me the chance to play with some lighting and a model that wont talk :)
 
Madpup said:
i read this post and thought i'll have a go,(big chunk of dust in veiwfinder)
first i cleaned the work area, waited for dust to settle.
dusted the camera so no stray dust would fall when dismantling
prepaired my swabs,
took lens off,
removed focusing screen (5D)
Click to expand...

Madpup - how does the focusing screen come out ? wonder if it comes out of a 350D?
 
Keltic Ice Man said:
Madpup - how does the focusing screen come out ? wonder if it comes out of a 350D?
Click to expand...

Here's full instructions for removing the screen on the 20D. I'm not sure if the screen on the 350 is user replaceable, but I've a feeling it isn't.

http://doug.kerr.home.att.net/pumpkin/Replace_focusing_screen_20D.pdf

Just be really careful and don't touch the mirror with your fingers or anything else. Unlike normal mirrors they're usually mirror coated on the surface and they're very easily marked.
 
Very similar to what I use - so it should work.
 
I would'nt bring it within 50 metres of my camera if I were you..

The guy who I buy my stuff from told me that those cans contain some harsh chemicals and also possibly microscopic metal flakes...

Maybe not this specific brand but then maybe it does so I wouldn't even clean the outside of my stuff with it.

:shrug:

Err on the side of caution I say:thinking:
 
I tried to clean my focusing screen when I had a bit of seaweed or something lodge up there during a lens change, I had CT's mobile number and made a rather panicked call to him from a caravan in Bridlington.

I'd only had the camera a few weeks.

Don't try and clean it with cotton swabs, its not a good idea ;)
 
382981591_c7881cf2f1.jpg
 
Iceman, theres a button right in the middle(not so much a button more of a grove) i pushed that and the screen fell down in a cradle.

ps jonnyreb... nice work, but oldgit was more, er "out there" lol
only joke, both are great and really helped.
 
Excuse us for using you thread for this KIM, n Guys, but we may as well knock up a nice one, ..err , I mean a clearer one ;) for general TP use.

Jonnyreb said:
382981591_c7881cf2f1.jpg
Click to expand...

The Grey side. :gag: :D

Yep, looks better in white Jonny. nice work. :thumbs:

It should look fine without the white background you've been forced to use in the merge. .. Can you get it to me with a link or in a PM? ...I can just copy a big version?
 
No worries - its sat at home so will send as soon as I get back this evening.
 
Phew - sorry Adam, got carried away doing something for Pete...... at last:
383973034_bb524d5232.jpg
 
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