Canon 400D + Nikkor 50mm f1.4 Non-Ai focusing problem

[Attila]

I sold a lens to our forum member Erez, he got this result. Is anybody has experience with Nikon pre-AI lens on Canon 400D ? I suppose must be works I guess the problem is my lens wasn't good. Any idea ?

[Ballu]

Which type of adapters were used, with focus confirmation chip or without the chip....

[Attila]

Is it makes any difference ?

[Ballu]

yes... sometimes the adapter chip is not fully compatible with Canon 400Dcamera.
If I got the issue right, the lens is doing front focusing. Is this the right assessment...

If this is the case, 400D may be culprit.

Plus, try to focus on cross contrasty lines, or basically try to do focusing in multiple location/situation. Canon low end cameras has eith straight or cross focusing sensor. I dont remember about 400D now.

[Attila]

Thank you Balu!

[Attila]

Sound this is exactly the lens fault, sorry mate.

[Orio]

I have many Nikkor lenses, most of them pre-AI, and never had a single problem with my 400D.
On the contrary, I'd call them the most reliable lenses for the 400D, focusing wise, as they have the longest register distance (longer than M42, Leica, and Contax-Yashica), so Nikkor to EOS adapters are the safest of all.

[Attila]

I got back this lens from Erez works like charm on my Olympus E-1 (Roxsen adapter) and works fine on my Nikon FA. This lens has an AI indexer even if looks non AI lens. Looks factory converted AI.
So seems not every lens works with every adapter, sorry Erez.I didn't know that till this time.I refunded your payment without postage cost, because lens was exactly as I described without any defect.

[440roadrunner]

I have had front focus problems with some manual lenses on my XT (350). I ended up testing my camera against the same model a friend has, using a Tamron 200mm, A Canon 50mm, and His Canon 400mmL. Both cameras gave almost exactly the same result, showing front focus problems with the manual lens with two different chip adapters. Both cameras focused nearly perfectly in the test using the Canon lenses. I used a small hard box with fine print, moved along a ruler.

Incidently I don't accept the "slanted ruler" as a legit test, because you really don't know for certain where the AF censor is hitting on the slanted scale.

I've forgotten exactly, but in the case of the 200mm Tamron, this amounted to 3/4-1" of front focus at about 8ft distance.

I've been experimenting with focus screens, having made one from an old Chinon, and finally, ordering a new Canon EC-b screen and cutting it down to fit my XT. I wanted the split screen.

Since this problem surfaced, I've been much more careful focusing. I wish to heck Canon had addressed this a little better, such as optional screens for the XT series, and a larger viewfinder. At nearly 60 years, my eyes aren't what they were, and it's uncomfortable for me to use glasses while framing.

[Orio]

[Borges]

Sometimes I read about front- or backfocus problems with adapted lens on EOS-Cameras. And sometimes the chip-adapters are blamed. I don't understand this idea and until someone has a good argument I can't believe it.

What is the function of the chip? Without the chip the camera don't has any information about the lens. Not the focal length, not the choosen aperture. The camera tries to choose a exposure, but we all know it's always a little bit wrong, depending on the aperture. Obviously, because the correct exposure has normally to be calculated inside the camera from the values of open aperture metering and the choosen aperture. Same with ETTL. The camera can't control the flash, because she didn't know the focal length and the aperture. Why in hell canon disabled the focus confirmation, I can't explain to myself. Perhaps because the camera can't decide wether to use the more sensitive cross sensor or not. For the cross sensor you need a designated maximum aperture value depending on the camera model.

So what does the chip adapter do? It sends some informations of a lens (not the real lens) to the camera. I have three different chip adapers. One claims that he is a 55mm f1.4 lens. So the camera calculates exposure, flash and so on for THIS aperture and THIS focal length. But this has nothing to do with focus confirmation. The camera calculates the correct focus through the lens. I think the only information the camera uses is the aperture to choose if the more sensitive cross sensor is used or the normal ones. And here perhaps is the problem (that has nothing to do with the chip): Perhaps the choosen working aperture is too dark for the cross sensors.

Another problem sometimes reported is that some adapters are not even, so the focal plane is not even.

So I wonder how the chip has something to do with this issue - but perhaps someone can convince me that I am writing nonsense...

Michael

[440roadrunner]

I cannot answer your question, but I can tell you the results I've gotten.

I have two chips which came from "Big_Is" on eBay. Both of these have trouble communicating with the camera, that is, you have to fiddle with them to get them to work, and sometimes they cause camera lockup, and you must remove the battery to "reboot."

(He actually sent me a second adapter and chip. It works just like the first)

The third and fourth chips came from EricC on ebay, and communicates every time.

However--any AF lens has a considerable amount of circuitry inside, and I've read numerous posts on the 'net where customers had sent BOTH lenses and camera in to Canon for adjustment. What this says to me, is that a simple 5 pin chip "built" by some guy in a basement may just not replace the considerable engineering in a given lens

In my case, I have now acquired a considerable amount of manual lenses. At this time, and until I decide which to keep, I have at least 4 different 200mm manual lenses. All four of these 200mm's exhibit front focus with my AF confirm chips.

I have two MF 300mm lenses, and both these, with some variance, tend toward front focus.

At this time, I have four AF lenses. NONE of these AF lenses exhibit front or back focus issues.

This testing was done by carefully locking out the AF on initial focus, then moving a box fore and aft 1/4" at a time for at least an inch

I also tested manual lenses of 50mm, 135mm, 300mm. With somewhat variation, all lenses showed some front focus. The interesting thing is, that the 50mm was the worst, and that is what the chip "says" the lens is!!

The interesting thing is, that I can see very little difference between the focus screen and the blip of the focus light. This includes the factory screen, as well as the two other screens, with both split screen and microprism

Now, so far as the comment that "I can't expect" a decent focus screen, I find that comment completely ridiculous. Focus screens are not expensive, and the Canon XT series already has a screen which can be easily removed. Canon could easily come along right at this time and build fittable screens for these cameras, and it would not cost much.

The whole thing is, Canon builds cameras and lenses. They of all people should know and should have known that we the customers are not always going to use AF mode, whether we have an AF lens or not. There are many times in low light or other situations where MF is desired. WHY ELSE would there be a switch on the side of the lens?

[Attila]

They can use many other lenses on Canon. I love Nikkor lenses and I loved very much my Nikon D50 I sold it and I bought an Olympus-E1 to use many MF lenses. Even if Olympus-E1 a very good camera I would get back my Nikon D50.

[440roadrunner]

[Attila]

You can't turn aperture ring on Non-Ai lenses when mounted to Nikon D50.But they are works very well with adapter ring on Canon and Olympus.

[440roadrunner]

So far as the comment on focus tests, I maintain that the 45 deg. inclined scales are NOT ACCURATE for one simple reason:

You do not know for sure where the AF sensor "sees." Therefore how can you possibly know what part of the inclined scale the bloody thing is actually focusing "on"?

[Attila]

I tested with Nikon D50 aperture metering started with D200. I guess it will works with your camera. Without AI conversation hard to use them because you need to set aperture before mount. (most of the time this is not a big problem, as usual I like to take photos with f/5.6 )

[Orio]

[440roadrunner]

Orio, I'd like you to define your idea of "having respect." Evidently, it means that just because I disagreed with you, then I'm showing disrespect.

You originally justified the lack of optional focus screens by just dismissing the DigiRebels as "a bottom end" camera. While these may indeed be the "bottom" of Canons DLSR line, they are hardly inexpensive in many people's eyes, even us "rich Americans." The 600US I paid for my XT was on closeout, and is STILL MORE MONEY than I have ever spent, either in real money or inflated figures, for any previous film bodies.

(Bear in mind that the Xt was considerably more than that amount at introduction. Bear in mind that traditional film bodies did not become discounted in the same relative time frame, years gone by)

Then in a following post, you make the statement that


"The main reason why Canon does sell a digital slr for about 600 Euros is that they want you to buy their autofocus lenses.
The reason why Canon and (as far as I know) the other camera producers, too, don't provide their consumer-level reflex cameras with alternative focusing screens for manual lenses has nothing to do with the cost, but rather with the above reason and this is called "marketing". "


I don't follow your logic there, either. If you want to market expensive AF lenses, then why would you (as Canon) provide ANY optional focus screens for any models of your camera bodies?

Obviously, Canon won't pour as much engineering money into the cheaper lines of products, but it just seems to me that the lack of a visual focus screen is glaring.

What it gets down to is simply this:

There are many, many times, when AF just isn't practical-regardless of the body, and Canon knows this, because there's a MF/AF switch right on the lens. Why they didn't follow it up with a decent focus screen is beyond me.

There just wasn't that many years ago, that no camera I used even HAD an AF/MF switch, and every one of the bodies I owned had a focus screen that worked. I've owned Mamiya, Pentax, Nikon, and Minolta, and even one Olympus through the years.


So far as the other's comments on metering, I've had various results with various lenses. It's interesting that metering problems seem to be inconsistent, as if the lens somehow is magic. I have two different 200mm lenses. One has almost NO metering issues, and the other becomes very underexposed below F8.

However, THANKS!! to one thing!! The magic of instant viewing, and exposure comp. and of course, photo software. Just remember, that these problems on a film body would have been disasterous.

[Orio]

[Attila]

I agree with Erez if you have a choice, focus confirmation is better choice than split screen.I use the most expensive Katz-Eye split screen to my Olympus E-1. I had experience with Nikon-D50 focus confirmation with MF lenses that was lot better.