View Full Version : Brevis + XH-A1 + Nikon lenses help needed
Giovanni Bertani
10-14-2007, 04:46 PM
1- Can you confirm that no extra macro is needed if I have a XH-A1 with acromat and spacer?
Should I live the spacer always mounted to get the best focus and no vignette?
2 - I am getting sharp images indoor and washed undefined images outdoors.
Should I try to leave the camera iris always open and act on the Nikon lens aperture?
Is it better to add also a polirized filter or a ND filter or both together?
Thanks...!
Jason Ramsey
10-14-2007, 06:50 PM
You don't want the camera's lens wide open. It is sharper closed down a bit. Or, at least I would assume this to also be true with the A1
An ND filter in front of your glass is what I have heard as being recommended, but you can certainly use the camera's nd filter.
Depending on your 35mm glass, it may or may not produce vignetting at wide open. I have heard the canon is a little more prone to vignetting.
I can't tell you about spacers and such with the A1. I just know that I don't need them with the HVX.
Later,
Jason
Lenilenapi
10-14-2007, 08:12 PM
This may be a question for people who have Bevis and Canon XHA1.
Does that camera have physical ND filters that slip in like on an HVX or a professional type camera or is it done electronically.
If the latter that could be the problem.
If your sharp indoors you should be sharp outdoors, but theer was a debate here about whetehr you needed external ND's for awhile that seemed to end up being around how your camera dealt with daylight.
Dennis Wood
10-14-2007, 09:16 PM
Washed, undefined images outdoors are indicative of hazing that occurs when the unit is subjected to a lot of light. We get very good results cutting light before it gets to the imaging element using external ND filters. If it appears that the images outdoors are hazed over, with loss of contrast, use external ND filters!
The XH-A1 does have internal physical NDs, but I rarely use them. Keep the XH-A1 at f 4 to f 5.6 if you can. If you have a spacer between the Brevis and the achromat ( it must be in that position) you should have plenty of zoom-in room, and no extra macro is needed.
What lens focal length and f stop range are you using?
Lenilenapi
10-14-2007, 10:04 PM
Giovanni, Were you using the XHA1's internal ND filters and stopping down the Canon's iris to get proper exposure?
I guess I'm wondering if you were just overexposing or actually did have the kind of hazing Dennis was describing?
If its just an exposure issue then you don't want to close the Nikkor much beyond f4, and instead use the Canon filters and iris to control exposure.
If your still getting hazing then follow Dennis' advice & get external ND's. You may prefer external ND's anyway - Dennis does and I have no experience with a Canon.
If it is hazing it would be cool if you posted the images since there was a big debate here last month about that and no one actually posted those kinds of pics. I'd like to see them myself.
Lenny
Giovanni Bertani
10-15-2007, 03:09 AM
Washed, undefined images outdoors are indicative of hazing that occurs when the unit is subjected to a lot of light. We get very good results cutting light before it gets to the imaging element using external ND filters. If it appears that the images outdoors are hazed over, with loss of contrast, use external ND filters!
The XH-A1 does have internal physical NDs, but I rarely use them. Keep the XH-A1 at f 4 to f 5.6 if you can. If you have a spacer between the Brevis and the achromat ( it must be in that position) you should have plenty of zoom-in room, and no extra macro is needed.
What lens focal length and f stop range are you using?
Ciao Dennis
Here we go:
1 Spacer was in the wrong position! I will change it today!
2 I am not using the Nikon lens aperture just the camera Iris and ND filters. So I will try a front filter on the lenses (Cavision ND).
Should I put only the ND or also the polirized one?
3 I will try a friend MatteBox to cut also some other reflections.
4 Here are my lenses:
ZOOM 70-210 mm 1:4 NIKON SERIES E
80-200 1:28 NIKON ED AF NIKKOR
50 mm 1:1.8
50 mm 1:1.2 (The one I was using yesterday on the Dolomites)
28-85 1: 3.5-4.5 AF NIKKOR
This last one is too slow so maybe I am going to buy the following lens instead as a Wide Angle for close indoor and scenary:
http://www.amazon.com/Sigma-20-40mm-Aspherical-Angle-Cameras/dp/B00009R6EI/ref=sr_1_2/104-1140454-9545520?ie=UTF8&s=electronics&qid=1191328052&sr=1-2
Even if... I have seen that disjecta is having very nice results with a fixed lens.
Thank you very much! :thumbsup:
BlueWorld
10-15-2007, 09:09 AM
1- Can you confirm that no extra macro is needed if I have a XH-A1 with acromat and spacer?
Should I live the spacer always mounted to get the best focus and no vignette?
Although some people have said they can focus without the spacer, I know we have been unable to get critical focus without the spacer, so it's on all the time. We're running A1->Achro->Spacer->Brevis.
3 I will try a friend MatteBox to cut also some other reflections.
In our experience a good mattebox is more important than the ND filters. I would never shoot outside without a MB and full set of flags. I'd be running an Arri MB-14 if didn't cost more than the A1.
jgastelb
10-15-2007, 11:31 AM
Maybe it's different with the A1 but I know that with the DVX100B if you want deeper field then you have to adjust that with the added lens. It certainly helps to close down a bit on your camera as well but the key factor, as I understand it, is the adapter lens controls your focus and the amount of sharpness, while your camera lens is used mostly for exposure along with the nd filters.
Jgastelb