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View Full Version : 35mm adaptors.. light loss?



daci
2009 June 7th, 05:32
Hi all
I'm looking into 35mm adaptors. twoneil, jag, and many upcoming choices there seems to be, but none of them list the estimated light loss. I just saw a video review of jag35 in which the reviewer said that it loses over a stop of light but he didn't specify which gg was on.
Would 5micron GG also lose over one stop of light?

Any particular adaptor known for minimal light loss? (beside letus or cinevate products, obviously)

sdeming
2009 June 7th, 18:00
I'm pretty sure both the Jab and The twoneil are great choices. I think you understand it's more about the gg than anything else-and both of those guys use great gg's in their respective products.

I'm gonna go ahead and say don't worry about the light loss, just look at the footage from each as well as the design and make your decision that way.

Snazzy Flapper
2009 June 7th, 18:12
But keep in mind that you WILL have light loss anytime you slap glass between the subject and your camera's sensor. It's not a non-issue.

And embrace the fact that shallow DOF is a function of lens focal length and aperature size. If you aren't artificially lighting indoor scenes you'll most definitly need to shoot with your 35mm lens wide open, which means incredibly shallow DOF.

So don't throw caution to the wind. Get educated and work within your means to achieve your desired result.

sirjoe
2009 June 7th, 18:37
I don't know about the canon EE-A, but i have 2 DIY adapters, one with the EE-S focusing screen, and one with a 5micron GG like jehu uses, and my 5 micron is noticeably brighter.

I know the canon EE-A is brighter but I don't know how much by.

designbydave
2009 June 7th, 22:54
...but he didn't specify which gg was on.

I'm pretty sure they are shipping all adapters with 5 micron screen standard now.

daci
2009 June 8th, 02:29
Thanks all for the replies.

I understand that light loss is inevitable with any 35mm adaptor. The lowest I've seen so far is letus or brevis that both boast 0.5 stop loss and they are more of highend commercial products.

I guess I've never heard any observation made on home brew adaptors regarding light loss and was wondering if anyone had data on it. For a similar quality/price range I would go for the ones with the brightest GG to save even a few more photons entering the small sensor ;)

thequads
2009 June 8th, 02:39
another contributing factor to light loss when using an adapter occurs when you have to zoom the camera into the ground glass. The camera will stop down as you zoom, thus closing the iris. I found out how bad this was when using the Hf-s100 with the sgblade 35mm adapter. You have to zoom in so much that I'm guessing I lost at least a couple stops of light.. it was that bad...

Maybe adding a telephoto adapter lens between the camera and 35mm adapter will help improve light loss.. because you don't have to zoom the camera so much.

Perladdict
2009 June 8th, 10:11
Were you using the SG Blade with the flip module on it, or just by itself? I posted a thread looking for some first-hand information and opinions from SG Blade users here: http://hv20.com/showthread.php?t=25938