4X Surprise Lens vs Nikon 4x Plan APO Can you tell the diff?

rjlittlefield · Post by **rjlittlefield** » Wed Jun 19, 2019 9:14 pm

Lou Jost wrote:Matte black spray paint.

That makes sense -- thanks.

--Rik

kaleun96 · Post by **kaleun96** » Wed Jun 26, 2019 12:56 pm

dickb wrote:
kaleun96 wrote:
dickb wrote:Cameron, how do you intend to use your XNP 23/1.4 (no longer 4.0)? Just with extension or with a tube lens?
Likely a tube lens such as the Redrock Micro 5x. It's a decently high magnification but I think I've pushed the 23/1.4 to about 6.5x or 7x already without issue. Super small DOF though.
OK, I'll try and include that one in my testing. If and when I get around to it - these optical tests have a way of being very time consuming if you try and do it correctly. In the next weeks I'll probably won't have the opportunity.

Just got my lens yesterday and tried to open it up today. I got the rear element group out easy enough but the front won't budge. I see there's a tapered shroud of sorts attached to the front group that provides the widest spaced slots for a lens wrench but that won't budge. There's also another set of slots, directly next to the front most element, that's a bit tricky to get a lens wrench into but even so I couldn't unscrew it either.

Any tips or tricks for removing that front group?

dickb · Post by **dickb** » Wed Jun 26, 2019 1:31 pm

kaleun96 wrote:Just got my lens yesterday and tried to open it up today. I got the rear element group out easy enough but the front won't budge. I see there's a tapered shroud of sorts attached to the front group that provides the widest spaced slots for a lens wrench but that won't budge. There's also another set of slots, directly next to the front most element, that's a bit tricky to get a lens wrench into but even so I couldn't unscrew it either.

Any tips or tricks for removing that front group?

One mine the widest spaced slots, just under the filter thread, came loose quite easily with a lens wrench. I say lens wrench, it actually was my calipers I often misuse as such..

dickb · Post by **dickb** » Tue Oct 08, 2019 12:53 pm

I did a quick run testing my Xenoplan 23/1.4, on a Canon 5D mk II, using a reversed Raynox 150 as a tube lens, resulting in a magnification of 9:1.

At f/1.4, there is considerable CA, f/2.0 is a big improvement in both CA and sharpness, f/2.8 is even slightly better, f/4.0 looks equally good. My camera may be the limiting factor here, though..

RobertOToole · Post by **RobertOToole** » Tue Oct 08, 2019 1:50 pm

dickb wrote:I did a quick run testing my Xenoplan 23/1.4, on a Canon 5D mk II, using a reversed Raynox 150 as a tube lens, resulting in a magnification of 9:1.

At f/1.4, there is considerable CA, f/2.0 is a big improvement in both CA and sharpness, f/2.8 is even slightly better, f/4.0 looks equally good. My camera may be the limiting factor here, though..

9x!

Stopping down with the lens iris or aperture disk?

This can make a nice difference. Some lenses work better with the factory iris. Most work best with a disk between lenses.

Robert

dickb · Post by **dickb** » Wed Oct 09, 2019 5:31 am

I used the internal aperture of the lens, since this was an exercise to determine the optimal f-stop for the fixed aperture version of this lens. I wouldn't call it a conclusive test though. You may well be correct in suggesting that the better strategy is to drill out the internal aperture entirely and just use a paper stop between tube lens and Xenoplan. I haven't tried that yet.

RobertOToole · Post by **RobertOToole** » Wed Oct 09, 2019 8:18 am

dickb wrote:I used the internal aperture of the lens, since this was an exercise to determine the optimal f-stop for the fixed aperture version of this lens. I wouldn't call it a conclusive test though. You may well be correct in suggesting that the better strategy is to drill out the internal aperture entirely and just use a paper stop between tube lens and Xenoplan. I haven't tried that yet.

For making stops, I got lucky, to save time and frustration of making disks by hand, I picked up a fiskar 50mm/2 inch craft hole punch cutter. The paper disks fit into my SM2/52mm system and 52mm step-up adapters with a snug fit so the apertures are well centered. Cost was less than $10.

I use a Japanese compass cutter for the aperture. These I find at the Japanese dollar store for $1.50 and the units even come with extra blades!

Best,

Robert

dolmadis · Post by **dolmadis** » Thu Oct 10, 2019 8:47 am

I came across a microscopist who had used one of the f4 versions reversed to an RMS adapter on a microscope which had a 200 mm camera tube lens mounted in place of a photo tube. The images looked good. Then I came across another user in that configuration and the images are even better.

Both were on a Facebook Group may be two Groups.

BR

John