Home

Please support mflenses.com if you need any graphic related work order it from us, click on above banner to order!
SearchSearch MemberlistMemberlist RegisterRegister ProfileProfile Log in to check your private messagesLog in to check your private messages Log inLog in

m42 > EF
Post new topic   Reply to topic
Home   Adapters and other accessories
View previous topic :: View next topic  


PostPosted: Wed Oct 20, 2010 8:54 am    Post subject: m42 > EF Reply with quote
Just saw this adapter on ebay, claims it has a new type of AF confirm chip, does anyone have more info on it? Has a 29 pound price tag, which is about 9 times more expensive than the regular non-AF confirm adapters out there, whats so special about it? Is it just seller hype?

http://cgi.ebay.co.uk/AF-Confirm-Chip-Adapter-CANON-EOS-M42-Lenses-/370434132854?pt=UK_Photography_CameraLenses_Lens_caps_hoods_adaptors_ET&hash=item563f984b76


PostPosted: Wed Oct 20, 2010 9:27 am    Post subject: Reply with quote
Well, these EMF chips are programmable and you can change aperture and focal length settings (and microadjust the AF for some cameras). These adapters usually come at higher price tag...

Beside proper Exif (interesting but not critical), I don't know if fine-tuning aperture and focal lenght is of any impact on quality of focus confirmation or (more likely) on exposure calculation. But I'm very interested in the answer Smile


PostPosted: Wed Oct 20, 2010 11:12 am    Post subject: Reply with quote
ylyad wrote:

Beside proper Exif (interesting but not critical), I don't know if fine-tuning aperture and focal lenght is of any impact on quality of focus confirmation or (more likely) on exposure calculation. But I'm very interested in the answer Smile

For these chips, aperture and focal length is not used on focus confirmation.


PostPosted: Wed Oct 20, 2010 11:46 am    Post subject: Reply with quote
I have tried the front/backfocus feature on my Dandelion russian chip IVth generation and it works (it requests some atention, time and repetitive tests,for getting accustomed with the procedure,though) I think it's useful , because there are lenses that do request microfocus adjustment.
http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&item=270524078428&ssPageName=STRK:MEWAX:IT
And it maintains infinity focus .

Last edited by yinyangbt on Thu Oct 21, 2010 9:45 am; edited 1 time in total


PostPosted: Wed Oct 20, 2010 11:49 am    Post subject: Reply with quote
calvin: I agree that they should not impact. But there are a couple of threads here that mention misfocus issues on AF adapter chips... Anyway, my main interest is on exposure, not focus.


PostPosted: Wed Oct 20, 2010 2:56 pm    Post subject: Reply with quote
ylyad wrote:
calvin: I agree that they should not impact. But there are a couple of threads here that mention misfocus issues on AF adapter chips... Anyway, my main interest is on exposure, not focus.

Even with the Canon AF lens, the misfocus will happen especially on lower end DSLR. The AF system will accept a certain tolerance. There is a thread on the other forum discussing the Canon AF system http://www.fredmiranda.com/forum/topic/241524 .

For the exposure, what I heard is the chip can impact the exposure but only to a to a small extent.


PostPosted: Wed Oct 20, 2010 3:38 pm    Post subject: Reply with quote
Focus: very interesting thread you've linked. I just read the first post, but it clearly states a link between focus and lens aperture (the max. aperture of the lens but not the actual one apparently - the post is dated from 2005 so things may have changed since then), it is key for the AF system to determine how to focus properly... As a consequence, ability to set proper aperture actually does impact AF.

Exposure: there are various threads in this forum that explain issues related to exposure calculation on Canon bodies (I can testify myself). No general rule there, but multiple testimonies. However, exposure calculation on EOS is made with wide-open lens but target aperture set. This is not how MF lenses are meant to work. This can be tricked by faking the aperture, locking exposure with lens wide-open and stopping down the lens. But to ensure proper calculation, you need to tell the proper max. aperture to the camera.

Therefore, many thanks to your questions and links, I can answer to myself Smile theoretically, programmable chip allows significant improvements on both focus and exposure determination by the camera.

Now, does it happen practically is another story that I can not answer myself Very Happy


PostPosted: Wed Oct 20, 2010 6:56 pm    Post subject: Reply with quote
Ahh I see, thanks for your replies Smile

So would you say its worth that much money? Or do you guys just stick with the el cheapo versions that don't cost twice as much as the lens you're adapting?


PostPosted: Wed Oct 20, 2010 7:13 pm    Post subject: Reply with quote
Look for "m42 eos adapter emf" worldwide on eBay. Some are from vendor Big_Is (written on the thumbnail) who has received good feedback from several members here. They are much cheaper.


PostPosted: Wed Oct 20, 2010 8:06 pm    Post subject: Reply with quote
I noticed an improvement in the focus after changing the focal length in the adapter. I believe it may have to do with the image stabilization on my Olympus E-510. On my Canon XTi I did not notice any difference at all.


PostPosted: Wed Oct 20, 2010 8:14 pm    Post subject: Reply with quote
I don't really rely on the AF confirm chips. They seem less accurate than my eyesight.


PostPosted: Wed Oct 20, 2010 9:30 pm    Post subject: Reply with quote
martinsmith99 wrote:
I don't really rely on the AF confirm chips. They seem less accurate than my eyesight.


+1

Saying that, the EMF chips (which have been around for a while now, so are NOT brand new...even 4th gen chips as far as I'm aware!) are much better, and the focus calibration makes them brilliant for infinity focus if you're adapter is a touch too thin.

As far as exposure goes, they don't help at all on Canons. Only a proper MF screen on a 40D/50D/5D/5DII/1D series body with appropriate menu setting will sort that (in my experience).


PostPosted: Fri Oct 22, 2010 8:27 am    Post subject: Reply with quote
ylyad wrote:
Look for "m42 eos adapter emf" worldwide on eBay. Some are from vendor Big_Is (written on the thumbnail) who has received good feedback from several members here. They are much cheaper.

I did check out the big_is ones, but ended up going for something cheaper, with a flange. Will post back on how that goes when I get it Smile
Post new topic   Reply to topic
Home   Adapters and other accessories
Page 1 of 1