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Focus screens - How to fit?
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Posted: Wed Feb 01, 2012 10:50 am
Post subject: Focus screens - How to fit?
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Posted: Wed Feb 01, 2012 10:50 am
Post subject: Focus screens - How to fit?
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So, I've bought a Split Prism Focus screen.

The old prism is out, and the problem I am having is getting the clip back in place. I can't get it to locate. Every time I push the clip, the 2 retaining lugs at the back pop out. I'm trying to reverse the process I used to take it out, and not having much luck.

I'm using the guide here...
http://www.focusingscreen.com/work/400den.htm

Any advice?

EDIT:-
It's the clips on the sides at the bottom of the retainer that I am having trouble locating.


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Posted: Wed Feb 01, 2012 11:22 am
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Posted: Wed Feb 01, 2012 11:22 am
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I remember it was tricky on the 400D, once I had to twist the metal a little, but it was used as I replaced the screen fifty time until it was correctly shimmed


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Posted: Wed Feb 01, 2012 11:37 am
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Posted: Wed Feb 01, 2012 11:37 am
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I'll have a break, and come back to it in a bit. I'll end up breaking something if I carry on now.

Just in case though... does anyone have Trifox's number? I may be needing to make use of his services.


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Posted: Wed Feb 01, 2012 9:37 pm
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Posted: Wed Feb 01, 2012 9:37 pm
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I'll wait for Trifox to get back to me I think, I'll end up breaking something other than the screen trying to get this to work. I'm not sure if it's the Screen, my technique, a broken clip or something that I'm missing.

Hopefully he can do better than Lehman's, who are very quick for spares (£12 for a new clip), but seemingly uninterested in a presumably higher margin Repair (and service, it could use a sensor clean too).


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Posted: Wed Feb 01, 2012 10:32 pm
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Posted: Wed Feb 01, 2012 10:32 pm
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Try the installation guide from this site:
http://www.katzeyeoptics.com/page--Custom-Focusing-Screens--store.html

easily done, but be careful when you grab the screen. grab only the tab, do not touch the screen surface. very easy to scratch.
you may need some washers in different thickness to calibrate the focus later.


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Posted: Wed Feb 01, 2012 10:56 pm
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Posted: Wed Feb 01, 2012 10:56 pm
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hoanpham wrote:
Try the installation guide from this site:
http://www.katzeyeoptics.com/page--Custom-Focusing-Screens--store.html

easily done, but be careful when you grab the screen. grab only the tab, do not touch the screen surface. very easy to scratch.
you may need some washers in different thickness to calibrate the focus later.


I had a good look there as well. I've Googled everything I can find. They had better pictures, but I still can't get the retainer to locate. It doesn't appear bent, the screen is in the right location, and in the right orientation according to those pictures. Everytime I push the front of the clip down towards the screen, the two lugs at the back pop out. I don't get annoyed very easily, but the whole lot nearly went in the bin earlier.

The screen is toast though... I slipped and put a scratch on it. I'll see if I can live with it if I manage to get it sorted... as long as the Prism functions as intended, I will probably call it good, as I've had a hair in my EOS1's viewfinder for 5+ years now... you learn to live with it.

I *must* be missing something, probably so obvious that no-one has thought to mention it... I'll have a good look again in a minute, now that I am not as annoyed, but unless I have a Eureka moment, I'll wait for someone to quote me on servicing, and use the D60 for the time being.


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Posted: Wed Feb 01, 2012 11:00 pm
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Posted: Wed Feb 01, 2012 11:00 pm
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I put a screen in an old EOS film camera, and the new one came with a little tool which made it very simple. Have you got the tool ? It might be different for a digital EOS, someone here will know. But if it helps I can mail it to you.


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Posted: Wed Feb 01, 2012 11:05 pm
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Posted: Wed Feb 01, 2012 11:05 pm
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The screen came with a (cheap) pair of angled tweezers, a short plastic rubber tipped pair of tweezers and a pair of finger cots. They seem confident that is all that is needed.

Have you got a pictures(s) of that tool?


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Posted: Wed Feb 01, 2012 11:53 pm
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Posted: Wed Feb 01, 2012 11:53 pm
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Is it possible you're trying to fit the screen upside down?

There is a rebate around the edge of the screen on one side only. The rebate has to be on the upper (viewfinder) side, so that it locates in the holding frame. If the screen is upside down it won't locate properly and the extra thickness prevents the clip lugs engaging in the slots.


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Posted: Thu Feb 02, 2012 12:43 am
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Posted: Thu Feb 02, 2012 12:43 am
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peterqd wrote:
Is it possible you're trying to fit the screen upside down?

There is a rebate around the edge of the screen on one side only. The rebate has to be on the upper (viewfinder) side, so that it locates in the holding frame. If the screen is upside down it won't locate properly and the extra thickness prevents the clip lugs engaging in the slots.


No. I don't think so.

The bevel on the Screen allows the screen itself to sit within the shim, which in turn faces into the viewfinder area.

I may have found my problem... The screen may be slightly warped. Pushing on the left hand locating lug (On the screen itself), there is little to no movement. Do this on the right hand lug, and it has downward play, as in you can depress it toward the shim slightly further. Given the movement in the "spring" on the retaining clip though, I wouldn't have though it was a problem, at least for it physically fitting, I suspect that optically, it will be a larger issue.

If that's the case, then I'll just have to bite the bullet send it to someone on payday to re-fit the original screen, and buy something with Liveview instead with this going to fund it. I may like to tinker, but this has given me a good scare, and I don't fancy screwing up another screen trying to get back to square one.

A large part of me is convinced that *I'm* cocking up something incredibly simple. I just have no idea what it is.


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Posted: Thu Feb 02, 2012 8:48 am
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Posted: Thu Feb 02, 2012 8:48 am
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NewStuff wrote:
A large part of me is convinced that *I'm* cocking up something incredibly simple. I just have no idea what it is.

Well, that may be true but isn't that the way we all learn? If it's any consolation, I screwed the first screen I tried to fit too. I didn't get the little kit you did and I used metal tweezers with tape over the tips and, would you believe, bare fingers! Rolling Eyes And after I'd got it worked out with the second screen, I had to remove and refit it three or four times before I got the shimming accurate, so practice makes perfect.

My screen wouldn't seat properly on its own too - it needed a little pressure. Put the clip roughly in place, then press down the screen with a finger tip inside the clip and this should allow the lugs to locate.


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Posted: Thu Feb 02, 2012 9:10 am
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Posted: Thu Feb 02, 2012 9:10 am
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I can get the rear lugs to locate, and the screen seems to be in place, but I cant get the front to locate. Every time I push downwards, the rear lugs pop out.

I'll give it another go tonight, as I'm off to work now.

Cheers for the advice though, it's much appreciated.


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Posted: Thu Feb 02, 2012 10:57 am
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Posted: Thu Feb 02, 2012 10:57 am
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The Canon tool makes it possible for the screen to be lifted from the box and inserted easily without touching it, the tool grips it in the box , then in the camera two lugs on the tool get pushed into the camera, spring inwards and release the grip on the screen, and the screen clicks into place

But this is a an old EOS 600 series film camera, the digitals might be different.


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Posted: Thu Feb 02, 2012 1:15 pm
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Posted: Thu Feb 02, 2012 1:15 pm
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The catch on my clip became bent inwards once. I needed to bend it out again to click in place.


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Posted: Thu Feb 02, 2012 1:19 pm
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Posted: Thu Feb 02, 2012 1:19 pm
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use sanitary rubber gloves. relatively clean environment. air blower ready. and dont breath into the sensor Smile
I scratched my first one too, in spite of all care and attention, and still few dust particles inside. I have learned to ignore them, and mostly forgot that they still there.


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Posted: Mon Feb 06, 2012 10:46 am
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Posted: Mon Feb 06, 2012 10:46 am
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The screen is the problem. I re-fitted my original one, and the clip went straight in. I re-tried the new screen, and the problem re-appeared.

I have emailed the seller, and they responded with a request for a picture. Even with a Tripod, I'm not sure I can sprout the extra hand needed to get a picture of it! I have emailed back a detailed description of the problem, and hopefully they will sort it without the need to open a dispute. Dependant on their response, I'll let people know to avoid or buy from them in the appropriate section.

Cheers for the input though, it's much appreciated, if only to make sure I am not going mad!


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Posted: Fri Feb 10, 2012 10:33 pm
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Posted: Fri Feb 10, 2012 10:33 pm
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Well, with a little Clip-bending, it's in!

I have a new clip on the way, and a new screen, but for now, this will work. The screen is not level, so I bent the clip to accommodate this warping. It seems to be pretty much spot on when indicating focus though.

I still want an NEX though Crying or Very sad


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Posted: Sat Feb 11, 2012 4:07 am
Post subject: Sane Once Again
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Posted: Sat Feb 11, 2012 4:07 am
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Congratulations! Glad you're back to sanity. Wink
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