Micro-Symmar 3.5x
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Re: Micro-Symmar 3.5x
I received the 3.5x lens today and ran some initial tests. First I did center-corner comparison at f2.8, but the CAs and resolution were not impressive, so I did a center aperture sweep. The sweep shows an optimum aperture for resolution and CAs between f3.5-f4.0. It's very disappointing to see this performance from such an expensive lens. My $50 Lomo 3.7/0.11 performs better.
Here are 100% crops of a scratch on the surface of a Cent. The scratch has significant specular reflection so makes a good CA indicator.
f2.8 f3.5 f4.0 f5.6
Here are 100% crops of a scratch on the surface of a Cent. The scratch has significant specular reflection so makes a good CA indicator.
f2.8 f3.5 f4.0 f5.6
Re: Micro-Symmar 3.5x
I'm sorry to hear that. I know that feeling very well
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Re: Micro-Symmar 3.5x
For folks who don't want to download and pixel peep the above, here's an animation at 200% near the center of the scratch:
- rjlittlefield
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Re: Micro-Symmar 3.5x
In the animation, it seems clear to my eyes that the f/2.8 image is showing finer detail, but the overall contrast is a little lower.
Do you see it differently?
--Rik
Do you see it differently?
--Rik
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Re: Micro-Symmar 3.5x
Yes, staring at the animation I agree the 2.8 shows finer detail, but worse CA and contrast.rjlittlefield wrote: ↑Wed Oct 14, 2020 8:37 amIn the animation, it seems clear to my eyes that the f/2.8 image is showing finer detail, but the overall contrast is a little lower.
Do you see it differently?
--Rik
Last edited by ray_parkhurst on Fri Oct 16, 2020 5:32 pm, edited 1 time in total.
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Re: Micro-Symmar 3.5x
Sorry to hear that, this lens had a rather mystical status in my book. It's scrubbed off now.
I agree with both Rik and yourself. Finer details at F2.8, lower overall contrast, but also quite a lot more CA.
The king of 3.5x still goes to the Rayfact I suppose, which needs 600mm of tubing. unwieldy
I agree with both Rik and yourself. Finer details at F2.8, lower overall contrast, but also quite a lot more CA.
The king of 3.5x still goes to the Rayfact I suppose, which needs 600mm of tubing. unwieldy
Re: Micro-Symmar 3.5x
Or some lens combo, which would need no extension at all....The king of 3.5x still goes to the Rayfact I suppose, which needs 600mm of tubing.
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Re: Micro-Symmar 3.5x
I'm not sure if any combo giving 3-3.5x magnification has been found with coverage beyond FF. I tested the RF3p5x out to 86mm IC and it actually improved slightly vs the central performance, so for now I would agree with @MC, but I would love to know a combo that can beat it.
Re: Micro-Symmar 3.5x
You can get larger image circles by using medium format tube lenses. There are some good ones (Mamiya 200mm Apo for example) and maybe some superlative ones like the Hasselblad 250mm Superachromat; when released, this was said to be the best-corrected commercial lens ever. It is so well corrected that it images into the infrared without the need for refocus. One of these is waiting for me in the US.
But working distance of most combos would be bad for your application.
But working distance of most combos would be bad for your application.
Re: Micro-Symmar 3.5x
Robert has some combos for stacked lenses around 3.5x with great performance on his site.
most likely the corner performance, flat field and distortion wont be as good as on the RF 3.5x though.
edit: as for medium format tube lenses:
the Contax 140mm is a fantastic lens on it's own and the Hasselblad 180mm is really good too, so they might be worth a try.
most likely the corner performance, flat field and distortion wont be as good as on the RF 3.5x though.
edit: as for medium format tube lenses:
the Contax 140mm is a fantastic lens on it's own and the Hasselblad 180mm is really good too, so they might be worth a try.
chris
Re: Micro-Symmar 3.5x
Sorry to hear the lens does not perform as expected. I promised myself I will no longer buy expensive, "exotic" lenses with no reliable tests backing them up, no matter how brillant they look on paper. Yeah, it's pretty exciting, but enough time and money spent/wasted is enough...
I still buy unknown, cheapo optics, in search of unpolished diamonds. Although 99.9% are "misses", I have fun testing them and it is not a big waste of money either.
Thanks for the test anyway!
- Macrero
I still buy unknown, cheapo optics, in search of unpolished diamonds. Although 99.9% are "misses", I have fun testing them and it is not a big waste of money either.
Thanks for the test anyway!
- Macrero
https://500px.com/macrero - Amateurs worry about equipment, Pros worry about money, Masters worry about Light
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Re: Micro-Symmar 3.5x
are these results to be expected based on the MTF's in the spec sheet?... the micro-symmar 3.5x when compared with the macro-symmar 5.6/80 1x show significantly reduced performance (results that is at the rated/designed magnification scale for each lens). or am I reading this incorrectly?
https://www.rmaelectronics.com/content/ ... 5.6-80.pdf
https://www.uniforcesales.com/wp-conten ... art-no.pdf
https://www.rmaelectronics.com/content/ ... 5.6-80.pdf
https://www.uniforcesales.com/wp-conten ... art-no.pdf
Re: Micro-Symmar 3.5x
MTF curves are based on magnification, and higher mag will result in a loss of MTF.bobfriedman wrote: ↑Sat Oct 17, 2020 5:03 amare these results to be expected based on the MTF's in the spec sheet?... the micro-symmar 3.5x when compared with the macro-symmar 5.6/80 1x show significantly reduced performance (results that is at the rated/designed magnification scale for each lens). or am I reading this incorrectly?
since the data sheet of the Macro Symmar 80mm is 0.5x, 1x, and 2x and the Micro-Symmar 50mm is at 3.5x, it's not possible to compare directly. one lens to compare it to would be the Inspec.x 4/105, which also shows the theoretical diffraction limited performance at each aperture:
https://www.qioptiq-shop.com/out/Graphi ... 1304_0.pdf
so that lens looks very close to the theoretical limit, but F4 at this magnification is already limited by diffraction.
a more modern lens would be the 128mm:
https://www.qioptiq-shop.com/out/Graphi ... 8174_0.pdf
(note that the 128 is at slightly lower mag 3.33x, but also the curves show 72lp/mm while the 105mm only shows up to 50lp/mm)
an other high end variant would be the the Mejiro FEH320 (note that the MTF here shows up to 100lp/mm):
http://www.visioneyes.co.kr/user/saveDi ... 0541_0.pdf
I'd expect the Rayfact 3.5x to perform very similar as those two lenses
chris
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Re: Micro-Symmar 3.5x
ok, I definitely agreechris_ma wrote: ↑Sat Oct 17, 2020 5:47 amMTF curves are based on magnification, and higher mag will result in a loss of MTF.bobfriedman wrote: ↑Sat Oct 17, 2020 5:03 amare these results to be expected based on the MTF's in the spec sheet?... the micro-symmar 3.5x when compared with the macro-symmar 5.6/80 1x show significantly reduced performance (results that is at the rated/designed magnification scale for each lens). or am I reading this incorrectly?
since the data sheet of the Macro Symmar 80mm is 0.5x, 1x, and 2x and the Micro-Symmar 50mm is at 3.5x, it's not possible to compare directly. one lens to compare it to would be the Inspec.x 4/105, which also shows the theoretical diffraction limited performance at each aperture:
https://www.qioptiq-shop.com/out/Graphi ... 1304_0.pdf
so that lens looks very close to the theoretical limit, but F4 at this magnification is already limited by diffraction.
a more modern lens would be the 128mm:
https://www.qioptiq-shop.com/out/Graphi ... 8174_0.pdf
(note that the 128 is at slightly lower mag 3.33x, but also the curves show 72lp/mm while the 105mm only shows up to 50lp/mm)
an other high end variant would be the the Mejiro FEH320 (note that the MTF here shows up to 100lp/mm):
http://www.visioneyes.co.kr/user/saveDi ... 0541_0.pdf
I'd expect the Rayfact 3.5x to perform very similar as those two lenses
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Re: Micro-Symmar 3.5x
Do you mean the Micro-Symmar 3.5x? For sure the Rayfact 3.5x outperforms both the 105IXL3p5x and the 50MS3p5x. I have not tested my 80MS at 3.5x, and am not sure why I'd consider doing so given its f5.6 max aperture. I would hope the newer 128DFHR would outperform the Rayfact, but the difference could only be marginal. The Rayfact has slightly better contrast and CAs at f2.8 vs f2.4, so the difference would be if the 128DFHR is better at f2.4 than f2.8.chris_ma wrote: ↑Sat Oct 17, 2020 5:47 amMTF curves are based on magnification, and higher mag will result in a loss of MTF.bobfriedman wrote: ↑Sat Oct 17, 2020 5:03 amare these results to be expected based on the MTF's in the spec sheet?... the micro-symmar 3.5x when compared with the macro-symmar 5.6/80 1x show significantly reduced performance (results that is at the rated/designed magnification scale for each lens). or am I reading this incorrectly?
since the data sheet of the Macro Symmar 80mm is 0.5x, 1x, and 2x and the Micro-Symmar 50mm is at 3.5x, it's not possible to compare directly. one lens to compare it to would be the Inspec.x 4/105, which also shows the theoretical diffraction limited performance at each aperture:
https://www.qioptiq-shop.com/out/Graphi ... 1304_0.pdf
so that lens looks very close to the theoretical limit, but F4 at this magnification is already limited by diffraction.
a more modern lens would be the 128mm:
https://www.qioptiq-shop.com/out/Graphi ... 8174_0.pdf
(note that the 128 is at slightly lower mag 3.33x, but also the curves show 72lp/mm while the 105mm only shows up to 50lp/mm)
an other high end variant would be the the Mejiro FEH320 (note that the MTF here shows up to 100lp/mm):
http://www.visioneyes.co.kr/user/saveDi ... 0541_0.pdf
I'd expect the Rayfact 3.5x to perform very similar as those two lenses
A potentially big issue with the 128DFHR is its LongCA performance. It looks like it has up to 300um focus error, which seems rather large for 3.5x. I don't think Rayfact shows either simulated or measured LongCA, but my tests did not indicate any significant LongCA issue. It's a shame about the 128 actually, since the 105 is a true apochromat, and has less than 100um of error. Simulated, I assume, but indeed my tests show that it is by my standards a nearly perfect lens within its max aperture limits. I would have hoped the 128 would be an apochromat as well.