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M42 to EOS with micro adjustment focus in EMF chip
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PostPosted: Tue Jun 04, 2013 7:21 am    Post subject: M42 to EOS with micro adjustment focus in EMF chip Reply with quote

Hi

I have several manual lenses and several adaptors from M42 or P/K to EOS with simple AF chip.
However most of the adapters/lenses suffers from significant front focus, when using with AF confirmation via viewfinder. That's why I moved to LiveView and focus is great, but I must admit I still prefer normal, optical viewfinder.
My EOS 600d does not have micro focus adjustment in the body and I wonder if adapter with programmable EMF chip will do the trick.

What do you think?
Will I be able to correct front focus and shoot wide open with acurate focus confirmation with EMF chip adapter?


I do not know if it is relevant, but standard 18-55mm kit lens autofocuses perfectly (checked wide open and it is about 1/3 in front and 2/3 behind the testing point). With this EMF micro adjustable chip I would like to use mostly 50ish primes with f/1.7

Any help and opinion would be appreciated.


PostPosted: Tue Jun 04, 2013 1:57 pm    Post subject: Reply with quote

I bought tones of chip chines adapters and also bought emf chip separately and glue them together. EMF chips can be adjusted but the best is live view.


PostPosted: Tue Jun 04, 2013 3:39 pm    Post subject: Reply with quote

Big_IS now sell a M42 adapter that includes EMF chip. I have one on its way to me. I will report once I test it on my Helio.


PostPosted: Tue Jun 04, 2013 4:02 pm    Post subject: Reply with quote

I recently got an EMF adapter for a Soligor 28mm. I was able to program it to correct a front focus problem. A little trial and error, but it worked. So I just ordered a bunch of chips to upgrade my M42's. This is definitely the way to go.


PostPosted: Tue Jun 04, 2013 4:52 pm    Post subject: Reply with quote

I understand the question is "Does EMF chip AF focus adjustment work on camera bodies without micro-adjustment feature?"

From EMF chip manual (http://www.emfphoto.com/forum/ )

Quote:
Note: The EMF focus micro-adjustment is not to be confused with AF
Microadjustment available on some EOS high-end cameras. EF lenses pass a Best
Focus Correction Value (BFCV – built in by the manufacturer) to the camera. This
enables the camera’s focusing system to compensate for variations between individual
lenses. The EMF adapter enables you to set a value for this for your lens-adapter
combination, but since you measure it yourself, it also renders the camera’s AF
Microadjustment unnecessary for your lens-adapter-camera combination.).

To make full use of the capabilities of the adapter, you will need to program the chip
in the adapter appropriately. Otherwise the default settings of 50mm, f/1.4, and no
focus micro-adjustment (setting 17) will be used. To program the chip you should
work through the following steps.
1. Mount the adapter on the lens, and the lens on the camera
2. Make appropriate basic settings on the camera
3. Activate the adapter programming mode
4. Enter a setting
a. Select a setting mode
b. Enter the appropriate value
5. Confirm the setting, and return the adapter to normal mode
Then:
6. Set the camera to record the correct working aperture in the EXIF data, and
take pictures.


PostPosted: Tue Jun 04, 2013 5:54 pm    Post subject: Reply with quote

"visualopsins" - well, you don't understand my question correctly, because I know it will be possible to correct front/back focus with EMF on body that doesn't have micro correction built-in. I'm more concern if it works in real life situation and was hoping for opinion of people who used it. Just like colleague "frenched" said.

"frenched" and "Srdjan" - thank you for your input.

"drjs" - I decided to buy m42 EMF adapter from Big_IS and I'm waiting. However it would be about end of June when it arrives, so maybe you'll be first to test yours and post some results Smile.

If it will work, and AF confirmation will be accurate, even with wide open apertures, I will get bunch of chips and replace simple AF chips in my adapters with this EMF one.


PostPosted: Tue Jun 04, 2013 6:26 pm    Post subject: Reply with quote

In past I was buying a lot of adapters and chips and put them as I said together and sell them to local people. I had lot of problems with adapters and chips because some of sellers are not so honest - missing screws, bed products, to big holes for camera needle so on and so on . But in time I find reliable sellers.
So I can recommend you dacheng2009, I used his EMF chips they are very cheap and they are working even at 6D, 5D III and 650d http://www.ebay.com/itm/EMF-AF-Confirm-chip-for-Canon-lens-EOS-EF-Adapter-/321009854571?pt=US_Lens_Adapters_Mounts_Tubes&hash=item4abdada86b.
If you interested in adapters I can look in my list and tell you, i can't remember at this time.


PostPosted: Tue Jun 04, 2013 7:39 pm    Post subject: Reply with quote

EMF chip AF confirm limitations exposed!

EMF chip AF accuracy depends on camera (QuickGuide to Accurate EOS Autofocus):

Canon wrote:
AF System Sensitivity
All EOS cameras have focus points that can autofocus
lenses with a maximum aperture of f/5.6 or faster. Some
camera models have additional sensors that provide extra
high-precision AF capability for lenses with a maximum
aperture of f/2.8 or faster.


On 5D with calibrated fast focus screen Ee-g I get precise AF confirmation with 50/1.4 and 35/2 lenses wide open. When focus in big viewfinder 'pops', the corresponding AF indicator lights. 'Rocking' focus, AF is indicated always the same place, unlike earlier AF chips, depending if focusing from far to near, or from near to far, indicated different in-focus positions.

On cameras with only f/5.6 capability, for faster lenses, the EMF chip micro-focus adjustment is merely a 'best guess' at real focus, based on a measurement at f/5.6. Depending if focusing from far to near, or from near to far, AF chip indicates different in-focus positions, at each of the f/5.6 in-focus positions.

I am guessing the EMF chip micro-focus adjustment is necessary only for EOS cameras without f/2.8 AF capability, that 'rocking' focus to find the two AF confirmations, then placing focus exactly in-between, will be necessary.


PostPosted: Tue Jun 04, 2013 9:39 pm    Post subject: Reply with quote

My EMF chips/adapters didn't come with instructions. You have to ask for them. I'll save you a step with this link: http://emfphoto.com/forum/index.php?topic=2.0


PostPosted: Wed Jun 05, 2013 5:58 am    Post subject: Reply with quote

"visualopsins" thanks for pointing out trouble with AF and fast lenses. Well I understand that a lot features are better and nicer on 5d than 600d, as the price is different too, and I am aware of it. However in connection what you have said I checked and I believe 600d has AF point for 2.8 or faster lenses as well, but only on its' center cross-type point.
I always wonder, however, if this Eg-S focusing screen is that a lot better for manual focusing even without AF confirmation?

"frenched" thank you a lot for the instruction, it will be helpful


PostPosted: Wed Jun 05, 2013 6:54 pm    Post subject: Reply with quote

Eg-S fast focus screen is absolutely necessary for obtaining accurate focus using the viewfinder -- dof of fast lenses cannot be seen using the standard focus screen; it is impossible.

I stopped using (older) AF chips because they use the camera f/5.6 focus system -- the AF points flashing distracted me too much. About 6 months ago I got a new adapter with the latest version EMF chip, which activates camera f/2.8 focus system. The AF lights in viewfinder flash only for exact focus -- when I see in-focus through the viewfinder, the AF point lights -- not so distracting. Much better, I'll keep the chip!


PostPosted: Wed Jun 05, 2013 8:46 pm    Post subject: Reply with quote

Thank you a lot for your replies. Now I wait to receive my adapter with EMF chip. I will post results of calibration as soon as I get my hands on EMF adapter Smile.


PostPosted: Thu Jun 06, 2013 11:55 pm    Post subject: Reply with quote

Maybe your focus screen is not calibrated to the sensor? I had a back focus problem with all my manual lenses and an aftermarket focus screen. I had to shim the focus screen in .03mm increments till I got it right. I used clear tape cut in thin strips as the shim.


PostPosted: Sun Sep 01, 2013 4:09 pm    Post subject: Reply with quote

Hi,

I decided to put this topic back alive, as I get EMF chips from Big_IS and tried to set up a few lenses.
1) Rikenon 55mm 1.4 M42
2) Jupiter 37A 135mm 3.5 M42
3) Tamron 17A 35-70mm 3.5 P/K

and it works almost perfectly on Jupiter and Tamron, while on Rikenon it is a lottery in confirming the focus.

I did not need to set Micro Adjustment for Jupiter and Tamron, but at default set up I get front focus on Rikenon repeatedly. With some trials I adjust micro regulation on adapter for Rikenon and thought that is it, it would be great. However now I am getting front and back focus lottery with Rikenon.
All at wide apertures of 1.4-2.8, when there is a lot of light. I know that DOF is really thin and it is easy to move out from focus, but I am not that bad camera holder Wink .

I would appreciate any suggestions or help as I really prefer focusing and composing through the viewfinder instead of using LiveView.


PostPosted: Thu Sep 05, 2013 5:37 am    Post subject: Reply with quote

I think chip on Rikenon adapter may be defective -- I would try using another adapter, from Jupiter, set up micro adjustment for Rikenon, to confirm.


PostPosted: Mon Sep 09, 2013 3:58 pm    Post subject: Reply with quote

As you know, microfocus settings are from 0-31 with 27 being the default. I read a post somewhere from big_is about how to go about doing the trial-and-error adjustments:

If the default value doesn't give good results, try 26 and 28. If you see improvement at 28, then try 29,30,31,1,2,3, etc. If you see improvement starting at 26, then try 25,24,23,22,21, etc. You should eventually hit it.

I did my adjusting at full aperture, camera on a tripod, shooting a ruler on the kitchen counter from an elevated angle. But Google will show other methods as well.


PostPosted: Mon Sep 09, 2013 6:40 pm    Post subject: Reply with quote

I've reset my Micro regulation and for now it looks I spot it this time.
Don't have time to test it properly, but as I took some test photos, it looks promising.
Let's hope that last time I was lousy with setting micro adjustments Wink