Redrock Macro adapter on SurplusShed

Lou Jost · Post by **Lou Jost** » Sun May 19, 2019 8:02 am

Dick, I had wondered if they had just assumed that, since it was in a metal casing. But I guess they are more careful than that.

I look forward to hearing how it does. I won't see mine until a few weeks from now.

dickb · Post by **dickb** » Sun May 19, 2019 8:46 am

Lou Jost wrote:Dick, I had wondered if they had just assumed that, since it was in a metal casing. But I guess they are more careful than that.

In one way yes, in another no. They sold the lenses as being unused, but one of mine looks like it had been taken apart. As they stated in their description: Retaining ring easily unscrews if you want to remove the cemented doublet achromat objective...

Lou Jost wrote:I look forward to hearing how it does. I won't see mine until a few weeks from now.

It looks quite good, I just tested it in normal orientation against a Raynox 150 in normal orientation, combined with my Canon 5D mk II and Xenoplan 28/2.0 reversed. I get a little less magnification, 6.8:1 vs 7:1 and the corners are a bit worse on full frame, but the centre is very good on both. I think the weakest link in my setup here is the camera. Maybe I should sell some more gear to get a better one..

Lou Jost · Post by **Lou Jost** » Sun May 19, 2019 8:50 am

I guess I didn't read the catalog entry very carefully.

That's too bad that the corners on FF are not better than our standard solution.

dickb · Post by **dickb** » Sun May 19, 2019 10:05 am

Lou Jost wrote:I guess I didn't read the catalog entry very carefully.

For this item at least they were quite accurate and informative, sometimes it is far more of a guessing game just what you will get in the post. The last time I bought some lenses there, the quality was varying greatly, with some lenses even missing some elements. This time it was ok, although I would have preferred if they had sent the optics in something sturdier than an envelope with a single layer of bubble wrap..

Lou Jost wrote:That's too bad that the corners on FF are not better than our standard solution.

Well, that is just a preliminary test, don't take it too seriously. I based it on single images, there may be field curvature that would be no problem when stacked I will do the same test with the achromat reversed. I should also try the Raynox 5320 for comparison. So many permutations. What would be a good lens to test it with so more people can judge its relative quality accurately? Is there a good standard lens for such a purpose? Or at least one that you are familiar with? I don't have any Mitutoyos but quite a few enlarger and machine vision lenses.

Lou Jost · Post by **Lou Jost** » Sun May 19, 2019 10:56 am

The Mitutoyo 10x has become sort of a standard, but since you don't have that, I don't really know what to suggest. Maybe others can suggest something.

dickb · Post by **dickb** » Sun May 19, 2019 11:41 am

Quick update, with the redrockmicro reversed I get the best looking images from my Xenoplan 28/2.0 to date, hardly any CA, not even wide open and high contrast. And that is wider than f/2.0, this lens even has an aperture stop marked beyond 2.0. Up till now this was always unusable because of the large amount of CA, but not with the reversed RRM5X. At f/2.8 and f/4.0 I get the best sharpness I've have seen, at f/4.0 including the corners.

Lou Jost · Post by **Lou Jost** » Sun May 19, 2019 12:54 pm

That's much better news!! Thanks for that update, which gives me new hope.

dickb · Post by **dickb** » Sun May 19, 2019 1:32 pm

A few quick samples: RedRockMicro 5x reversed, Schneider Xenoplan 28mm f/2.0 at f/2.8 and 6.5:1

centre

edge

corner

No post processing on this image, no sharpening, no CA reduction. OK so the corners are not perfect, but like I said, this is just a single image. As you can see even the dust lying on the wafer shows next to no CA. Compared to the other tube lenses I've tried so far this is a great improvement.

Thagomizer · Post by **Thagomizer** » Sun May 19, 2019 9:26 pm

dickb wrote:Quick update, with the redrockmicro reversed I get the best looking images from my Xenoplan 28/2.0 to date, hardly any CA, not even wide open and high contrast. And that is wider than f/2.0, this lens even has an aperture stop marked beyond 2.0. Up till now this was always unusable because of the large amount of CA, but not with the reversed RRM5X. At f/2.8 and f/4.0 I get the best sharpness I've have seen, at f/4.0 including the corners.

Pardon my ignorance, but I'm guessing you're using the Redrock Micro as a tube or primary on the camera lens with the Xenoplan mounted on the RRM5X? Are you using extension between the RR and your camera? Do you have a picture of your set-up? If it's not inconvenient, I'm curious. My initial intended use for the Redrock is on some of my walkaround zooms to give them "instant macro" capabilities. I'm interested in what others are using it for and what other tricks this optic has up its sleeve.

dickb · Post by **dickb** » Mon May 20, 2019 7:42 am

Thagomizer wrote:Pardon my ignorance, but I'm guessing you're using the Redrock Micro as a tube or primary on the camera lens with the Xenoplan mounted on the RRM5X? Are you using extension between the RR and your camera? Do you have a picture of your set-up? If it's not inconvenient, I'm curious. My initial intended use for the Redrock is on some of my walkaround zooms to give them "instant macro" capabilities. I'm interested in what others are using it for and what other tricks this optic has up its sleeve.

Correct. There are many threads here on this forum on tube lenses. Here is a quick phone picture of my setup:

The idea is that the tube lens is focussed on infinity and it projects the image formed by the primary lens onto the sensor. For the reversed RRM5x the distance for infinity focus is 135mm from Canon EF mount to the female 72mm thread of the RRM5x. At the moment I used a variable or helicoid tube for quick testing, for a more permanent setup I would use fixed tubes for a more rigid setup that is easier to flock properly.

Thagomizer · Post by **Thagomizer** » Mon May 20, 2019 12:41 pm

Thank you for the explanation of your set up.

dickb · Post by **dickb** » Mon May 20, 2019 1:03 pm

You're welcome. A few more quick tests, the Nikon Plan 10x 0.25 inf looks pretty good as well. I also tried one permutation of the Raynox 5320 pro as tube lens lens, reversed, with the 2D nearest to the camera and then the 3D. This results in a little longer tube, and also very decent results.

Lou Jost · Post by **Lou Jost** » Mon May 20, 2019 1:09 pm

dickb wrote:A few more quick tests, the Nikon Plan 10x 0.25 inf looks pretty good as well. I also tried one permutation of the Raynox 5320 pro as tube lens lens, reversed, with the 2D nearest to the camera and then the 3D. This results in a little longer tube, and also very decent results.

Which would you say is better?

dickb · Post by **dickb** » Mon May 20, 2019 2:13 pm

Lou Jost wrote:
dickb wrote:A few more quick tests, the Nikon Plan 10x 0.25 inf looks pretty good as well. I also tried one permutation of the Raynox 5320 pro as tube lens lens, reversed, with the 2D nearest to the camera and then the 3D. This results in a little longer tube, and also very decent results.
Which would you say is better?

I can't tell for certain yet, I only tested one configuration of the 5320 so far, and the tube length may not have been exactly optimal. So far I have seen slightly better results from the RRM5X, even less CA and a slightly flatter field. But I am aware my test isn't perfect, in that the number of focussed test photos is limited and there may be inconsistencies in the alignment of the lenses and the subject, so your mileage may vary

Lou Jost · Post by **Lou Jost** » Mon May 20, 2019 2:16 pm

Still, this information is very encouraging. Can't beat the price!