Search found 1656 matches

by RobertOToole
Sun Mar 01, 2020 10:51 pm
Forum: Equipment Discussions
Topic: Saving a Schneider Componon From the Trash Bin
Replies: 6
Views: 955

Saving a Schneider Componon From the Trash Bin

Had an interesting experience yesterday where I was able to rescue a lens from the garbage, the original owner thought the lens was hopeless and was going to bin it, I was able to talk him into sending it to me for a look. The fix was really easy, take a look, I hope others will find this as interes...
by RobertOToole
Sun Mar 01, 2020 10:17 pm
Forum: Equipment Discussions
Topic: Rodenstock Rodagon 150mm f/5.6 rear diamater?
Replies: 20
Views: 1927

When you pull down a lens with short focus you can pull some lenses down quite a bit but all will eventually suffer IQ loss in the corners. I think this might happen sooner than later with a high-NA lens. Robert, I was thinking more about spherical aberration and perhaps other issues. There was a p...
by RobertOToole
Sun Mar 01, 2020 11:37 am
Forum: Equipment Discussions
Topic: Rodenstock Rodagon 150mm f/5.6 rear diamater?
Replies: 20
Views: 1927

When you pull down a lens with short focus you can pull some lenses down quite a bit but all will eventually suffer IQ loss in the corners. I think this might happen sooner than later with a high-NA lens. Robert, I was thinking more about spherical aberration and perhaps other issues. There was a p...
by RobertOToole
Sun Mar 01, 2020 11:28 am
Forum: Equipment Discussions
Topic: Schneider Componon-S 135mm vs Raynox DCR-250 Tube Lens Test
Replies: 12
Views: 1430

Oscar_macro wrote:Thank you for all these tests and share them, they are a great help!
Glad you find these helpful, and thanks for taking time to comment.

Robert
by RobertOToole
Sun Mar 01, 2020 12:18 am
Forum: Equipment Discussions
Topic: Rodenstock Rodagon 150mm f/5.6 rear diamater?
Replies: 20
Views: 1927

Robert, Regarding short focus of a converging lens, I keep wondering if it will have a detrimental effect with a high-NA objective. We have theory that it might be problematic, but I don't recall seeing any tests. You have a Mitututoyo 100x/0.70, don't you? :D --Chris S. Good memory Chris! I do hav...
by RobertOToole
Sat Feb 29, 2020 9:35 pm
Forum: Equipment Discussions
Topic: Schneider Componon-S 135mm vs Raynox DCR-250 Tube Lens Test
Replies: 12
Views: 1430

Very useful comparison, Robert as always. Thank you for that! And smashing cover photo :D Who is your designer? Best regards, Miljenko Do you really like it? :D I must be doing something right, that was my favorite version out of about 5 designs I tried. The funny part? I have something like $50K i...
by RobertOToole
Sat Feb 29, 2020 9:24 pm
Forum: Equipment Discussions
Topic: Rodenstock Rodagon 150mm f/5.6 rear diamater?
Replies: 20
Views: 1927

The Rodagon 135 has one flaw - it is too close to Raynox 250, which I already have. I don't need that fine magnification steps ... at least not yet. :) The other steps are Canon 100 L IS Macro and Raynox 150 for ~175 & 208 with the Century +4 as next step when I find one. Corner shading could indee...
by RobertOToole
Sat Feb 29, 2020 10:37 am
Forum: Equipment Discussions
Topic: Rodenstock Rodagon 150mm f/5.6 rear diamater?
Replies: 20
Views: 1927

Thanks Robert! I was thinking as a tube lens. With the short focus results you've had I thought it should be fine, but I don't have the lens ... yet. Anytime. As an alternative the 135mm Rodagon, and that would fit in the M42 tube for sure but you have to be careful of corner shading with a full fr...
by RobertOToole
Sat Feb 29, 2020 9:11 am
Forum: Equipment Discussions
Topic: Zhongyi (Mitakon) Super Macro Lens (1 - 5x)
Replies: 264
Views: 38559

with extended holidays, finally got some time to do some work. But today a big BUG caught me, spent 2 hours debugging it, it turns out at 1:1 with Zhongyi Super Macro Mk II, magnification is NOT 1:1, it is 1.16:1, or 1.16x. I thought I had some bug in my software and it is "good" for others to be a...
by RobertOToole
Sat Feb 29, 2020 9:03 am
Forum: Equipment Discussions
Topic: Schneider Componon-S 135mm vs Raynox DCR-250 Tube Lens Test
Replies: 12
Views: 1430

I presume the softness in the lower left corner of Raynox corner crop is due to field curvature? In that corner I don't see how it could be anything else. Yes, true, the Raynox in reverse setup had a narrow band of depth of field compared to the Componon-S. Kind of a bummer unless you are shooting ...
by RobertOToole
Sat Feb 29, 2020 9:01 am
Forum: Equipment Discussions
Topic: Schneider Componon-S 135mm vs Raynox DCR-250 Tube Lens Test
Replies: 12
Views: 1430

Hi Eric, Sorry if this is a stupid question, but I've been experimenting with stacked lenses. I make ever effort to focus the tube lens as sharply as possible on a distant object, at infinity. When you say "short focus, that is past infinity", I take it you mean focus to infinity and then bring the ...
by RobertOToole
Sat Feb 29, 2020 8:49 am
Forum: Equipment Discussions
Topic: Rodenstock Rodagon 150mm f/5.6 rear diamater?
Replies: 20
Views: 1927

Thanks Robert! The ID is 38, so no-go. Back to the drawing board... What is the position sensitivity for the Rodagon? Does it matter at all if it is say 3 mm off in either direction? Hi JKT, The position depends, for use as a tube lens or taking lens? From my experience this week testing a 135mm tu...
by RobertOToole
Fri Feb 28, 2020 10:47 pm
Forum: Equipment Discussions
Topic: Schneider Componon-S 135mm vs Raynox DCR-250 Tube Lens Test
Replies: 12
Views: 1430

Added a 2500 pixel sample to the test page. Click on the thumbnail image below to open a larger image in a new window. Also you can right or two finger click and select open in new tab or window or you can always save as and view the image with another app. http://www.photomacrography.net/forum/user...
by RobertOToole
Fri Feb 28, 2020 8:34 pm
Forum: Equipment Discussions
Topic: Schneider Componon-S 135mm vs Raynox DCR-250 Tube Lens Test
Replies: 12
Views: 1430

Schneider Componon-S 135mm vs Raynox DCR-250 Tube Lens Test

http://www.photomacrography.net/forum/userpix/3062_CoverSchneiderCompononS56135vsRaynox125mm8dioptertubelenswwwCloseuphotographycom_1.jpg This is a follow up to the 135mm enlarging lens test posted earlier this week: https://www.photomacrography.net/forum/viewtopic.php?t=41183 This time I am testin...
by RobertOToole
Fri Feb 28, 2020 6:48 pm
Forum: Equipment Discussions
Topic: Rodenstock Rodagon 150mm f/5.6 rear diamater?
Replies: 20
Views: 1927

Re: Rodenstock Rodagon 150mm f/5.6 rear diamater?

The title says it all. :) I found a catalog, which gave the length of the rear part and flange distance, but the diameter is open. The question is whether I can squeeze it inside T2 extension tube. Hi JKT, Depends on the tube. I have a 5.6/150mm Rodagon here. I tried it on a M42 and there is a litt...