My idiot question of the week: Do WA adapters let more light in? at DVinfo.net

Go Back   DV Info Net > The Tools of DV and HD Production > Open DV Discussion

Open DV Discussion
For topics which don't fit into any of the other categories.


Reply
 
Thread Tools Search this Thread
Old June 2nd, 2009, 10:06 PM   #1
Trustee
 
Join Date: Jan 2008
Location: North Conway, NH
Posts: 1,745
My idiot question of the week: Do WA adapters let more light in?

If you've never seen my other idiot questions, don't worry. I keep them to myself so that no one knows what a pillock I really am. (grin)

The specific question is, will a good quality wide angle adapter bring in more light thru the lens than the same camera without one? My uninformed guess is yes, maybe... I know there will be light loss because of the WA adapter. The f value of the adapter would help me figure that out but that whole chain of math is really lost on me.

Here are the specifics. Century Optics 37mm .55WA attached to either a Canon HV10 or HF100. Shooting outdoors under marginal artificial light. Motor racing, of course.

The reason I ask is that I'm now using the adapter on the HF100 for a locked off speed shot right past the finishing line. With the adapter, the field of view is the whole finishing line all the way back to turn four. Without it, I lose either the whole line or part of turn four. Either wouldn't be optimal.

So far the adapter works well there from late afternoon through night, capturing great twilight skies as a racing backdrop. So I don't expect to change it. I was just very curious if I was gaining or losing a lot of light by using it.

TIA.
Tripp Woelfel is offline   Reply With Quote
Old June 3rd, 2009, 01:01 PM   #2
Major Player
 
Join Date: Jul 2005
Posts: 562
Tripp:

Lock the camera down, set the iris manually with the wide angle in place, then remove it. What happens to the exposure?

Just to my eye, the extra incidence of gathered light with a wide angle is generally off set just a bit by the extra glass it passes through, making the camera just a tad less light sensitive, but I'd be willing to go either way, based on your camera and the quality of the wide angle lens.
Bill Ward is offline   Reply With Quote
Old June 4th, 2009, 04:43 AM   #3
Trustee
 
Join Date: Jan 2008
Location: North Conway, NH
Posts: 1,745
Bill... Your suggestion would provide much more practical information than the answer to my theoretical question. In a moment of pre-caffine clarity I realized that the WA adapter could result in significantly less overall light getting in if the increased field of view contains a lower average light level.

In theory, it would seem that if the camera was focused on a solid middle gray wall, the light let into the camera would be the same with the adapter as without, less the loss induced by the adapter itself. Since few of us shoot monochromatic backgrounds I think the technical answer to my theoretical question would not provide much useful information overall.
Tripp Woelfel is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

Professional Video
(800) 833-4801
Portland, OR

B&H Photo Video
(866) 521-7381
New York, NY

Z.G.C.
(973) 335-4460
Mountain Lakes, NJ

Abel Cine Tech
(888) 700-4416
N.Y. NY & L.A. CA

Precision Camera
(800) 677-1023
Austin, TX

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > The Tools of DV and HD Production > Open DV Discussion

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



Google
 

All times are GMT -6. The time now is 07:57 PM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2017 The Digital Video Information Network