Manual or Standard lens on XL2?

Marty Hudzik · March 16th, 2005, 08:43 AM

For what it is worth:

I used the 20x lens with the century optics .7x WA adapter for 2 months and shot about 6-7 hours of footage. I would consistently see a slight backfocus problem with this combination. I would review footage later and find softness in many, many shots which would p*** me off to no extent. However when I would use the 20x by itself it was not evident. The image remained very sharp through the range.

For whatever reason that same exact .7x wa adapter performed flawlessly on the 16x manual lens. I however set the backfocus myself using the flange on the lens. The combo of the 16x manual and .7x is nothing short of amazing for me. I get the wide range I want and a decent amount of zoom too. The image is sharp all the way through the range except at the widest setting where the .7x adapter shows a little softness-chromatic issues at the very far left and right of the screen. I can live with this for now as I lover everything else about this conbo.

For some reason the .7x adapter just does not deliver a consistently sharp image with the 20x for me. OThers may see dofferent results but this alone pushed me to use the 16x manual almost all the time.

Now outside doing wildlife or sports where I need to zoom I still use the 20x for its OIS. I don't do a lot of rack focusing and my DOF is pretty deep (it's usually daylight so I stop down)so focus issues don't pop up in this environment as much.

Tony Davies-Patrick · March 16th, 2005, 12:31 PM

Deep DOF can be a problem when you first adjust back-focus with a .7X optic on the 16X manual. If you try to adjust with the aperture set at medium aperture openings, that extended DOF can make you think that the focus adjustment is spot-on...even though in reality, it is often slightly out. However, I have learnt that it is always better to adjust back-focus only with the lens at its widest F/1.6, tighten the screw, and then close down to correct aperture for the exposure.

I also sometimes override the minimum focus of the 16X + .7X lens combination, by focussing at closest range, and then re-adjusting the back-focus lever again to allow really tight wide-angle macro shots.

Marty Hudzik · March 16th, 2005, 01:05 PM

Tony,
I do the same thing. I set the backfocus on the .7x and 16x manual together. It allows for extremely tight close to the lens shots without going into the macro setting. It still retains perfect focus through the entire range too.

Having been able to tweak my backfocus makes me wonder how I ever managed without this feature. You "know" 100% for sure that your focus is crisp everytime because you set it. Period. I know the servo lenses are suppossed to automatically correct for temperature shifts and what not but I'd rather have the control in my hands.

March 16th, 2005, 12:31 PM	#17
Tony Davies-Patrick Trustee Join Date: Feb 2005 Location: Worldwide Posts: 1,589	Deep DOF can be a problem when you first adjust back-focus with a .7X optic on the 16X manual. If you try to adjust with the aperture set at medium aperture openings, that extended DOF can make you think that the focus adjustment is spot-on...even though in reality, it is often slightly out. However, I have learnt that it is always better to adjust back-focus only with the lens at its widest F/1.6, tighten the screw, and then close down to correct aperture for the exposure. I also sometimes override the minimum focus of the 16X + .7X lens combination, by focussing at closest range, and then re-adjusting the back-focus lever again to allow really tight wide-angle macro shots. __________________ www.WILDCARP.com www.NIKON.me.uk

March 16th, 2005, 08:43 AM	#16
Marty Hudzik Trustee Join Date: Jul 2004 Location: Canton, Ohio Posts: 1,771	For what it is worth: I used the 20x lens with the century optics .7x WA adapter for 2 months and shot about 6-7 hours of footage. I would consistently see a slight backfocus problem with this combination. I would review footage later and find softness in many, many shots which would p*** me off to no extent. However when I would use the 20x by itself it was not evident. The image remained very sharp through the range. For whatever reason that same exact .7x wa adapter performed flawlessly on the 16x manual lens. I however set the backfocus myself using the flange on the lens. The combo of the 16x manual and .7x is nothing short of amazing for me. I get the wide range I want and a decent amount of zoom too. The image is sharp all the way through the range except at the widest setting where the .7x adapter shows a little softness-chromatic issues at the very far left and right of the screen. I can live with this for now as I lover everything else about this conbo. For some reason the .7x adapter just does not deliver a consistently sharp image with the 20x for me. OThers may see dofferent results but this alone pushed me to use the 16x manual almost all the time. Now outside doing wildlife or sports where I need to zoom I still use the 20x for its OIS. I don't do a lot of rack focusing and my DOF is pretty deep (it's usually daylight so I stop down)so focus issues don't pop up in this environment as much.

March 16th, 2005, 01:05 PM	#18
Marty Hudzik Trustee Join Date: Jul 2004 Location: Canton, Ohio Posts: 1,771	Tony, I do the same thing. I set the backfocus on the .7x and 16x manual together. It allows for extremely tight close to the lens shots without going into the macro setting. It still retains perfect focus through the entire range too. Having been able to tweak my backfocus makes me wonder how I ever managed without this feature. You "know" 100% for sure that your focus is crisp everytime because you set it. Period. I know the servo lenses are suppossed to automatically correct for temperature shifts and what not but I'd rather have the control in my hands.