EOS Auto focus confirm chips

john_van_v

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Hello everybody, this is way off topic, but I trust people here far more than elsewhere, so here goes...

I have been using an EOS camera for night shots as a stopgap until I can set up darkroom to do proper film speed pushing. It is a Canon XT, and, yes, digital still sucks.

Focusing is my problem, since the viewfinder is so ridiculously small. As I use the camera I wish it was a rangefinder.

Has anyone had experience with the digital chips that glue onto EOS adapters that are called "auto focus confirm?" I have read that they may work on 35mm EOS but may fry out an EOS dSLR. But then I see a lot of them being sold on ebay.

I have been shooting with a Rexagon 28mm and a Fujica 55mm.

Rexagon 28
http://picasaweb.google.com/john.van.v/Eos_rexagon_28


Fujica 55
http://picasaweb.google.com/john.van.v/Eos_fujica_55mm
 
They work perfectly OK for any EOS camera when positioned correctly.

There should be some websites telling you how to glue the chip onto the adapter yourself. While that may not be what you plan to do, you can go there and see what a correctly glued chip looks like and hopefully help you spot incorrectly glued chips on fleebay.

The big problem with focusing SLRs at night is the dim viewfinder. Even the AF system quits at night on my 30D when the exposures go more than 15 seconds. Usually, I have to use manual focusing (i.e. guesstimation) for night shots. The good thing is that my night shots are usually scenery and aren't on the move.
 
Truthfully, I am having trouble focusing in broad daylight with the 28, thought the 50 seems easier -- maybe the extra stop helps.

I don't find the stop-down focusing too inconvenient as setting exposure is a separate action from focusing, and I want to know what the depth of field is going to be.

I have been planning to buy the chip alone to attach to my most-used adapter, probably the m42.

Do you have actual experience with a "auto focus confirm" chip?

They work perfectly OK for any EOS camera when positioned correctly.

There should be some websites telling you how to glue the chip onto the adapter yourself. While that may not be what you plan to do, you can go there and see what a correctly glued chip looks like and hopefully help you spot incorrectly glued chips on fleebay.

The big problem with focusing SLRs at night is the dim viewfinder. Even the AF system quits at night on my 30D when the exposures go more than 15 seconds. Usually, I have to use manual focusing (i.e. guesstimation) for night shots. The good thing is that my night shots are usually scenery and aren't on the move.
 
I have used them many times before and can say with good certianty, don't bother. It essentially is doing the same thing auto focus is doing and seeing if the thing you want is in focus, but auto focus systems are not as accurate as manual focusing. Using a focus confirm chip with a m42 50mm lens on the 5d my miss rate was about 60% and that sucks. The camera said it was on focus but it just wasn't. I have used a few other adapters on the 5d as well like nikon and c/y all with focus confirm. The results were about the same.

My advice, just get a manual focus screen with a split prism, they are the next best thing to good ground glass or a rangefinder
 
I've used auto-focus confirm chips with Nikon, Olympus and Leica adapters on my Canon 5D. With 50 lenses and 90mm lenses I can focus more accurately by eye than with the chip. Even more so with the Canon replacement focusing screen which is better for manual focusing. I haven't much experience with non-EF wide angles on the 5d, perhaps the chip may be more useful here?
 
Wow, thanks for the advice Nkysoon and Avotius. I have a Canon XT, so I will google for a split image focusing screen.

I really cannot wait 'til I get a darkroom set up so I can escape back into the analog past. I am starting to think "medium format."
 
I think what you want to look for is called a katzeye or something like that. They make screens for all sorts of different cameras.
 
I agree with the negative comments above. I had one from a very reputable seller, but could never get it to sit right on my EOS-1 (film). Once I did get it to work, it wasn't accurate. Better off with your eyes or with one of the split screens.
doug
 
John, actually I shoot a lot with my XT and manual lenses. The AF-confirm chip is better than nothing. If you can get a katzeye o.t.e. that would be much more fun for manual focusing.
Another advantage of the split-screen is that this nervous AF-points will disappear from the XTs viewfinder.

My 2cent...

Regards, Axel
 
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