A100 shutter button and viewfinder

[roysmith]

Hi, I've bought an used A100 and the shutter button sometimes feels a bit slow/sticky. I've read that many Canon users clean the D30/D40 by just pouring some isopropyl alcohol around the button, pressing it a few times and letting it dry a couple of hours. Do you think this is safe to do with the A100? Any other simple method to try? I don't want to dismantle the whole thing, I prefer to live with the button as it is in case this is too complicated to fix.
And another thing, the viewfinder seems darker/muddier/less clear than my A700's... it seems to have less "resolution" and it shows some kind of flares. The glass looks clean but I'm not sure if this is normal. Could this be because of a dirty focusing screen or it's just the way it is? How simple is to clean the focusing screen?

BTW I'm using the new Sigma 17-50mm f/2.8 OS HSM and it's fantastic. Much better than my old SAL18250. Much better contrast, faster and quieter AF, more resolution and a lot brighter (the viewfinder looks much brighter now).

Thanks!

[Juanito200]

Hey roysmith- I don't know about the alcohol. There are some fast evaporating electronics cleaners that I would try before dumping alcohol on it.
As for the viewfinder, have you checked the diopter setting? ( the little wheel by the viewfinder) It may been set by the previous owner to correct their vision. That could cause some of the symptoms you describe. If the focusing screen is dirty, it shouldn't be hard to clean.
Also, the a100 viewfinder is a pentamirror design, not a pentaprism design like the a700. A pentaprism viewfinder will be brighter, etc, than a pentamirror design. It is similar to my a200's viewfinder, and I find it hard to go back to the a200 after shooting with the a700.
How is that new Sigma lens? I was thinking about it as a replacement for my 18-70 kitlens, and possibly my 16-105 as well. Please post some pics!hiccup! Hope this helps John

[Greg Beetham]

The shutter button is a very close fit to the housing so even a fine dust particle seems to cause it too stick on occasion. Mine started doing weird stuff and that's all it was just a bit of dust in the button, you can free it up with a pin or a needle, use the point of the pin on the edge of the button to rotate it while blowing on it.
I wouldn't attempt anything with the viewscreen myself, from what I've seen in the past with anyone's handywork in that area you've a really good chance of making things worse. I think the best bet for that one is too send it to a qualified camera repair facility.
Greg

[David Kilpatrick]

You can't clean a focusing screen without an ultrasonic bath. The finder is dimmer than the A700 by a long way and lacks the A700 contrast. That is simply what a pentamirror finder looks like. Other suggestions are all sensible.

David

[roysmith]

Thank you all. I've already adjusted the diopter, it's the first thing I do But now that you mention it... maybe that can be part of the problem, it seems the diopter has less range of adjustment than the A700's, and I always used the A700 at -3. I've just checked the A100 specs and it only goes up to -2.5. So that can be the "muddier" part of the problem. The "darker" part it's already answered I think, because of the pentamirror vs pentaprism.

I've already tryied with a blower to clean the shutter button but it still feels sticky. I've tested rotating it with a needle while blowing but didn't get any better... seems to have some dirt stuck at the sides. Using isopropyl alcohol is not a good idea then? Any idea of a specific product to use to release that dirt?

About the Sigma 17-50 2.8 I'll make a new thread on the right forum and post a couple of test pics, since it's new and I don't have any "real" pics yet

Thanks again!

[Greg Beetham]

Dirt? that's a new one, I guess you could try and hold the button up on one side with the needle and try brushing the other side of the button with somthing like a dry toothbrush maybe, and blowing too.
Greg

[redsim74]

Using isopropyl alcohol is not a good idea then? Any idea of a specific product to use to release that dirt?

I'm having issues with the shutter button on my A700 vertical grip. DK suggested using contact cleaner.

I haven't tried it yet but I'm very familiar with the product (having lost potentially millions of brain cells using it during my time as a technician ). It comes in an aerosol can and you want to be sure to use a "plastic safe" variety. Something like CRC "CO" Contact Cleaner. You should only need to use a little squirt.