That makes sense -- thanks.Lou Jost wrote:Matte black spray paint.
--Rik
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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.dickb wrote: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.kaleun96 wrote: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.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?
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..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?
9x!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..
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.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.