Search results for 'back focus' - page 2047
SMC 18-55 DA
I don't like that concept D800, it doesn't look handy at all and actually more vulnerable to my eyes... Also the D800 would probably be quite a lot bigger than the K5. hmmm lets see... IN the large green and red box, there would be 2 in each but i've no idea where the silver go and whe...
Posted by Anvh on 05/05/2011 - 22:43
Dust on ,my focus screen
I've got an annoying piece of something on my focus screen, I assume it's that as it shows in the viewfinder but not on the images. Is there a way to get rid of it? Blow it off maybe?
Posted by Karl on 06/05/2011 - 17:14
Dust on ,my focus screen
Rocket blower.
Posted by johnriley on 06/05/2011 - 18:07
Dust on ,my focus screen
Beg to differ John, Rocket blowers just move the problem, usually top somewhere less accessible. Arctic Butterfly every time, for any detritus. Davex.
Posted by davex on 06/05/2011 - 18:49
Dust on ,my focus screen
You don't use an Arctic Butterfly on focusing screens and mirrors. I have found holding the camera facing downwards spots in the viewfinder system can be removed easily with a rocket blower. As regards the sensor, the built in dust removal system works most of the time and a rocket blower the res...
Posted by johnriley on 06/05/2011 - 18:59
Dust on ,my focus screen
Thanks for the advice, I'll give it a puff with the blower!
Posted by Karl on 06/05/2011 - 19:00
Dust on ,my focus screen
I've got dust behind the focus screen before. Lean the camera over Karl and there is a little switch which can click the screen out. Use the blower and click the screen back in place. :)
Posted by GDN on 06/05/2011 - 19:05
Dust on ,my focus screen
Beg to differ John, Rocket blowers just move the problem, usually top somewhere less accessible. Arctic Butterfly every time, for any detritus. Davex. I also use it on the mirror and focusscreen, i doubt the little bit of pressure will do any harm, the mirror experience a lot more forces when i...
Posted by Anvh on 06/05/2011 - 19:28
Dust on ,my focus screen
The focusing screen is very soft plastic and should not be touched. The mirror mechanism is a very highly precise bit of engineering that should not be touched, lest it gets pushed out of position. If the mirror isn't precisely in position your images will have a focus error. This is one of t...
Posted by johnriley on 06/05/2011 - 20:31
Dust on ,my focus screen
Thanks for the help. Happy to report that the offending particle blew off.
Posted by Karl on 07/05/2011 - 08:12
Dust on ,my focus screen
If the mirror isn't precisely in position your images will have a focus error. But come on, the mirror is basicly slammed open and close so how can that tiny bit of force you might apply with the brush move it around... if it does i would sent it back to pentax since i wouldn't trust it :|
Posted by Anvh on 07/05/2011 - 17:47
Dust on ,my focus screen
It isn't slammed open and closed Stefan, it's a precision mechanism that can be easily knocked out of balance. In addition, it's a front surface mirror and the coating is also fragile.
Posted by johnriley on 07/05/2011 - 18:04
Dust on ,my focus screen
So the forces you apply with the brush are greater than the forces when the mirror moves? Is sure believe you that it's precision mechanism and fragile but i don't believe it's that fragile that the forces of the brush will actually do any harm unless you are using a hard brush of course but we a...
Posted by Anvh on 07/05/2011 - 18:41
Dust on ,my focus screen
You'll have to decide what you do for yourself, but to be honest it discourages me from buying second hand DSLRs that some users do seem to be over-zealous in their treatment of the presision mechanisms.
Posted by johnriley on 07/05/2011 - 19:13
Dust on ,my focus screen
Well you can always get the brush visibledust (articbutterfly) make for cleaning the mirror and focusing screen but i've no idea what the difference is between the normal one? http://www.visibledust.com/products3.php?pid=603
Posted by Anvh on 07/05/2011 - 21:23
Dust on ,my focus screen
I totally agree with John's point of view. Never touch a front surface mirror with anything! It is really vulnerable. And any forces applied to a mirror apart from the pivoting around its support axis may well upset the alignment. I think you overestimate the "slamming" forces, Stefan.
Posted by terje-l on 07/05/2011 - 22:46
Dust on ,my focus screen
I think you overestimate the "slamming" forces, Stefan. The mirror start moving quite abruptly and is basically "slammed" against the stop at the top. I don't know how heavy the mirror is and how fast it moves but i would find it very strange that the force you apply with a soft brush would be grea...
Posted by Anvh on 08/05/2011 - 10:05
Dust on ,my focus screen
Well you can always get the brush visibledust (articbutterfly) make for cleaning the mirror and focusing screen but i've no idea what the difference is between the normal one? http://www.visibledust.com/products3.php?pid=603 There is probably no difference at all!....just a way of extracting more c...
Posted by beginner on 08/05/2011 - 10:20
Dust on ,my focus screen
Yeah maybe. Btw are there liquids you can use to make the mirror anti-static? I mean the mirror moves up and down with every shutter actions so if it would be anti-static i doubt any dust will be able to stay on for long...
Posted by Anvh on 08/05/2011 - 10:41
Dust on ,my focus screen
The mirror is already treated by the manufacturer - add other liquids and the effect on those coatings is unknown.
Posted by johnriley on 08/05/2011 - 11:34
