Low light huh?

Since it's not a cine lens, the T-stop, the actual stop, is a bit slower than the f-stop.

Good shooting and best regards,

Leo
 
LoganMackay said:
Not possible for it to lose light. No glass to cut it out.

"should" be brighter is very situational as well.
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It seems like the adapter is preventing the aperture blades from opening completely.
The "situation" is what was presented in the clip.
Compared to slower glass and other night tests I've seen....something is not jiving with my camera.
 
Johnf said:
So I'm not imagining this then?
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Imagining that it 'should' be brighter? Put that lens on another camera, crank it up to 3200iso and do a side by side with the AF100 and you *may* have your answer. I say *may* because there are so many other variables that could be in play with electronic capture.

Seems from your other posts that you aren't happy with the camera?
 
Ok, you didn't include the part about the adapter not allowing the aperture to fully open. That would make things darker, yes.

What I mean about this being situational is that we can't know how dark it was, and how bright the image should be. The footage looks just fine to me.
 
Someone should probably define T stops, since they are a film thing and not seen much in the still or video worlds.

When zoom lenses, and some other multi-element specialty lenses, were developed it was discovered that the theoretical amount of light passing through the lens was lessened because of reflection and refraction within the lens, between all that glass.. So T stops, which mean "transmission stops", were developed which measure the actual, rather than theoretical, amount of light passing through the lens... This is overly simplistic and I am not a lens expert, but it's close to correct...
 
For the ultra low light stuff that seems to have become popular with DSLRs, I don't think 2.8 is fast enough. Go to F1.4, you'll have 4 times as much light!
 
You've really not conducted a test, you're simply thinking that there is less sensitivity or incorrect ASA in the camera.

You can easily verify; get a accurate light meter and grey scale chart; light to, say 5.6 at 400 ASA and check the waveform. If camera and light meter agree, then check other ASA settings. Then check through your f-stops on your lens to see if they agree with the light meter. It would be extremely helpful if you can use a proper cine lens at first; meter & camera should be dead on.

It could be possible that the adapter is restricting the lens; you should be able to look and see if the iris is fully open with the adapter in place. Just hold it up and look.

Good shooting and best regards,

Leo
 
Johnf said:
It seems like the adapter is preventing the aperture blades from opening completely.
Click to expand...

LoganMackay said:
Ok, you didn't include the part about the adapter not allowing the aperture to fully open. That would make things darker, yes.
Click to expand...

Yeah - that would affect the final outcome… Maybe try with an adapter / lens combo that works before you point the finger?
 
easy way to see if the aperature is all the way open, take it off the camera, leave the adapter on the lens, and look through the lens, if you see the iris edges, then i'ts probably not wide open, most if not all lenses' max aperatures are when the iris wides to beyond the inner case, hence you should see a perfect circle, no blades, when looking through a full wide open lens
 
Matt Duclos measured the Tokina 11-16 and the T-stop matched the F stop value. So for this lens that is not an issue.
 
What other settings are you using? Frame rate, shutter speed, and all the scene file settings could be impacting your final image.

I agree that the results you're getting don't look as good as others shot at 3200 ISO, but there are more variables to consider, including the fact that many others have been using that voightlander .95 lens, which is infinitely faster then what you're working with.

Don't write off your camera just yet, I'd say keep tinkering with the settings.
 
Thank you.
NOWHERE did I ever state that I didn't like the camera!
Just trying to figure out if it was a limitation of the lens, adapter or both.
 
John, if i understand you correctly, when you have the lens off the adapter and push the aperture tab with your finger it opens all the way, but when mounting it to the adapter and turning the blue ring to the open iris position, the iris does not fully open? If that's the case then i would think wrapping a bit of tape around the adapters tab that contacts the lens tab would give it the extra push to get the iris all the way open.
 
I think this is a great example of issues arising from use of NON -MANUAL still lenses and adapters.

You just do not actually know what the stop you have set is and all you can do is rely on the waveform and zebras.

I would agree that that the lights inthe image should have been a bit brighter, but I aslo see that the blacks are over exposed. My guess is that scene is not very "bright" in the first place.
 
Johnf said:
....something is not jiving with my camera.
Click to expand...

I thought you were suggesting that perhaps your camera was faulty, which is why I mentioned camera settings. Can't really comment on the lens, I don't have any experience with the Tokina or the Novoflex.
 
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