Do Cinema cameras have mirrors in front of the sensor?

[Hakob Hakobyan]

Hi guys,

So I was looking at My C100 mkii and noticed some dust spots in it as shown in the attached picture.
It is stupid not to know but do Canon Cinema cameras have mirrors in front of their sensors like DSLR's?
I don't know if these dust spots are on the mirror or the sensor?
If it is mirror I will try to clean it but if it's the sensor I will send it in for cleaning.

Thanks!

[Christopher Young]

Unlike DSLRs most video cameras have some kind of glass filter in front of the sensor. It serves a number of purposes. Its primary purposes is that it is part of the light ray alignment path from the lens to the sensor. In many cameras it also functions as part of the IR filtering and lastly a beneficial function in that it does help in keeping dust etc off the filter wheel assembly and the sensor itself.

Quite often this filter section is made up of a number of glass laminations with each layer of glass having certain correction properties. Over the years I have had to replace a number of these filter blocks in broadcast camera as the bonding agent in-between the laminations can start to deteriorate. This is evidenced in certain areas of the image not looking quite as sharp as other parts of the image.

Back to your can you clean this filter block and the answer is yes. Probably the safest way for an individual to clean the filter without sending it in to Canon is to use an Arctic Butterfly cleaner. This sends a small electric charge to its cleaning brush to create a static field that attracts dust to make the cleaning effort much more effective.

https://visibledust.com/products/arc...gital-cameras/

If this process doesn't give you a clean filter glass then it's probably best to to send it in to Canon.

TAKE HEED OF MY NEXT STATEMENT as I take no responsibility if you get it wrong.

On a number of occasion on broadcast OBs when we had problems with 2/3" cameras with junk that really got stuck to the sensor filter I used to use cotton tipped buds and Isopropyl alcohol.

Q-tips®

Very carefully cleaning the junk off with one cotton bud with a little Isopropyl and then using a second dry cotton bud to gently wipe the area where the Isoproyl had been used. Worked every time.

Good luck!

Chris Young
CYV Productions
Sydney

[Gary Huff]

Originally Posted by Christopher Young

Very carefully cleaning the junk off with one cotton bud with a little Isopropyl and then using a second dry cotton bud to gently wipe the area where the Isoproyl had been used. Worked every time.

ABSOLUTELY DO NOT DO THIS unless you want smears on the glass and a $500 repair bill from Canon, like I did. Arctic Butterfly is your best choice before sending it in.

[Chris Hurd]

Catch your Arctic Butterfly here:

https://www.bhphotovideo.com/c/product/712189-REG/Visible_Dust_5964480_Arctic_Butterfly_724_Super.html/BI/2855/KBID/3801

Or here:

https://www.amazon.com/VisibleDust-Arctic-Butterfly-Super-Bright/dp/B004DAE7UC/dvinfo09-20

Hope this helps,

[Christopher Young]

Originally Posted by Gary Huff

ABSOLUTELY DO NOT DO THIS unless you want smears on the glass and a $500 repair bill from Canon, like I did. Arctic Butterfly is your best choice before sending it in.

Exactly why I included the warning before suggesting it would be best to send it into Canon

In the broadcast world where on every OB the cameras have to be assembled with their box lenses and then disassembled for pack up it is almost impossible to not get dust in them occasionally. There is no way a broadcaster can send the cameras back to Sony or whoever for cleaning every time this happens. It's up to the camera dept back at base for the cameras to be checked and cleaned. Obviously if this happens in the field one of the techs from the OB truck would clean the sensor filter.

It is a regular procedure and done often. Because you weren't taught how to do it properly and just because you had a failure doesn't mean it can't be done. It sounds like you didn't use a 100% pure Isoproply. I admit it was an omission not to have mentioned the 100% because some Isoproply solutions on the market aren't 100% pure.

Chris Young
CYV Productions
Sydney

[Noa Put]

+ 1 for the Arctic Butterfly, it's not cheap for just a rotating brush but I have been using one for years now, I use it before every shoot. Only if I would have spots on the sensor that the brush can't remove I would send the camera in.

[Paul Mailath]

Originally Posted by Christopher Young

It is a regular procedure and done often.

- not something I want to do often but it has worked well for me. I've had equal success with the fluid & swabs available at B&H and a cotton bud in an emergency.

[Gary Huff]

Originally Posted by Paul Mailath

- not something I want to do often but it has worked well for me.

With a Canon EOS C-series camera?

[Christopher Young]

Originally Posted by Paul Mailath

- not something I want to do often but it has worked well for me.

Agreed. Here is a useful little video from AbleCine showing you how to clean the IR/OLPF filter on most cameras.

https://www.abelcine.com/articles/bl...a-dirty-sensor

Chris Young
CYV Productions
Sydney

[Chris Hurd]

Great link! Thanks for sharing that. Here's the video:

YouTube (Short URL)