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Old 25-09-2008, 08:36 PM
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seeker372011 (Narayan)
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getting a modded Canon 300D to focus with the 50 mm f1.8

I have a modded Canon-but one of those with no replacement filter-ie only the original IR filter ripped out

it doesnt come to focus with the 50mm f/1.8....is there a solution?
thanks for any suggestion
Narayan
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Old 25-09-2008, 09:25 PM
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Narayan with the filter totally removed it has lost its auto function capabilities, due to the fact the the camera was calibrated with the thickness of the filter taken into account, with this now gone it will not come to focus unless you use some sort of focusing software aid.

Even looking through the view finder, and manually focusing will not do it.

I think i'm right here, but maybe others here will add some more info for you.

Leon
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Old 25-09-2008, 09:29 PM
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[1ponders] (Paul)
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Are you using software to assist your focusing or simply eyeballing it through the viewfinder?
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Old 25-09-2008, 10:05 PM
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I am actually using DSLR focus..I am not even sure eyeballing works now that the IR filter has been stripped, but I am short sighted and astigmatic- and find it hard to squint through a viewfinder with glasses-so no, I rely totallly on DSLR focus..and I cant seem to get it in focus
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Old 25-09-2008, 10:07 PM
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Leon is correct, even eyeballing it will get it wrong, as the mirror is placed at a set distance to replicate the focal plane of the filter equipped chip at the viewfinder..

I believe there is a screw inside the body that can fine tune the autofocus (that might just be with the 350D/20D however. I'll have a look in my 300D when I get home...
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Old 25-09-2008, 10:10 PM
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Using DSLR focus should work.. ??
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Old 26-09-2008, 01:07 AM
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See here on how to adjust focus.
http://astrosurf.com/buil/autofocus/adjust.htm

The 50mm F1.8 is difficult even with trial and error. Put a sticky label on the barrel and focus ring with marks to get focus. I have a stepper motor and dead printer belt to control focus and it is the only thing that works for me.

Bert
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Old 26-09-2008, 06:54 AM
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Quote:
Put a sticky label on the barrel and focus ring with marks to get focus.
Definitely helps. I also found placing a bit of blu-tak against the lens body and the focus ring to provide a bit of resistance and prevent the ring from "free moving" helped enormously.
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Old 26-09-2008, 11:41 PM
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Quote:
Originally Posted by avandonk View Post
See here on how to adjust focus.
http://astrosurf.com/buil/autofocus/adjust.htm

The 50mm F1.8 is difficult even with trial and error. Put a sticky label on the barrel and focus ring with marks to get focus. I have a stepper motor and dead printer belt to control focus and it is the only thing that works for me.

Bert
that site is in french unfortunately and not one of the languages I know

looks really useful..if I could only make out what they are saying !

the sticky label idea sounds good will give it a go
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Old 27-09-2008, 05:15 AM
DeanoNZL (Adrian)
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Handy translator
http://babelfish.yahoo.com/
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