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Exposure jumps with adapter (confirm chip)
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PostPosted: Wed Jan 12, 2011 10:58 pm    Post subject: Exposure jumps with adapter (confirm chip) Reply with quote

Hello,
I'm having problems in video mode with an adapter with chip confirm I bought on ebay from HK (I'm not gonna put the link cause IMHO they are all equal).

I experienced many times that while shooting videos the exposure changes (down) by like 1/3 stop for half a second and then goes back to where it was. Did anybody have this experience?

The chip is very helpful for pictures, but I was wondering if someone found a solution or if there are "better" chips that don't show this bug. Yes I know that buying an adapter without a chip will be right thing to do (and I will) but I usually take pics and videos on the same "moment" and changing the adapter seems a little uncomfortable.
I noticed that while using the adapter in manual mode in my camera menu (550d) I see that focus goes from MF to One Shot and viceversa continuously .


PostPosted: Wed Jan 12, 2011 11:33 pm    Post subject: Re: Exposure jumps with adapter (confirm chip) Reply with quote

sandro wrote:
Hello,
I'm having problems in video mode with an adapter with chip confirm I bought on ebay from HK (I'm not gonna put the link cause IMHO they are all equal).

I experienced many times that while shooting videos the exposure changes (down) by like 1/3 stop for half a second and then goes back to where it was. Did anybody have this experience?

The chip is very helpful for pictures, but I was wondering if someone found a solution or if there are "better" chips that don't show this bug. Yes I know that buying an adapter without a chip will be right thing to do (and I will) but I usually take pics and videos on the same "moment" and changing the adapter seems a little uncomfortable.
I noticed that while using the adapter in manual mode in my camera menu (550d) I see that focus goes from MF to One Shot and viceversa continuously .


I had the same problem and the solution was to get another chip. I never really bothered to really find out why it did this but it might have something to do with the placement of the chip, if it's slightly off it might behave like that.

I recomend the never chips, the ones with the programmable aperture and focus adjust feature. I use one on my Planar 85 1.4 and Sonnar 180 C/Y with super results. I can take pictures of moving subjects wide open with super sharp results. With this chip the lens will behave just like and EF lens, if you use Canon of course. You will even get that litte red square that shows you where you focused. I hope this helps. The link is for C/Y to EOS adapter but the chip is available for M42 also.

Here is a link

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=350414335843&ssPageName=STRK:MEWNX:IT


Last edited by Omar on Wed Mar 02, 2011 9:17 am; edited 1 time in total


PostPosted: Wed Jan 12, 2011 11:36 pm    Post subject: Reply with quote

Did you have the problem in video mode?


PostPosted: Wed Jan 12, 2011 11:41 pm    Post subject: Reply with quote

sandro wrote:
Did you have the problem in video mode?


Yes, only in video mode with my old camera, the 7D. With this new adapter it works like a dream.


PostPosted: Wed Jan 12, 2011 11:50 pm    Post subject: Reply with quote

Do you think this one will also have the problem fixed?
The thing is that not even the sellers are aware (or they pretend to) of this so they couldn't actually point me to the right adapter


PostPosted: Thu Jan 13, 2011 12:25 am    Post subject: Reply with quote

sandro wrote:
Do you think this one will also have the problem fixed?
The thing is that not even the sellers are aware (or they pretend to) of this so they couldn't actually point me to the right adapter


I can't really say if this adapter will have the problem or not. I noticed that the focal length is fixed to 50mm but the aperture can be changed.

My experience is that you gett better focus with adjustable focal length and aperture. Try the one I linked to but get it with an M42 adapter instead.


PostPosted: Thu Jan 13, 2011 12:35 am    Post subject: Reply with quote

I need Nikon F adapter. Maybe the new ones with EMF chips don't show the problem


PostPosted: Sat Feb 12, 2011 3:00 pm    Post subject: Reply with quote

I had a similar problem, but only noticed this after I had already transcoded video to Apple ProRes 422. I checked the original mov on the SD card and it was fine. Not sure why the conversion created an error, but strangely the error was exactly as you described... as if the aperture ring closed down a stop, then returned to normal after a few seconds.

Thankfully, re-encoding it fixed the problem.