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charley5
Joined: 11 Feb 2020 Posts: 346 Location: India
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Posted: Tue Feb 11, 2020 8:07 am Post subject: Aperture Control Adapter Question |
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charley5 wrote:
Hi Everyone:
I just purchased a Rodenstock Heligon 95mm f0.95 projector lens for a Sony mount, to be used on my Sony A7ii. The lens however is a little soft wide open, so I thought to get an aperture control adapter. I am hoping to increase sharpness and eliminate a little vignetting on my full frame camera. The aperture control adapters I have seen all seem to work from a different mount (such as Canon) to the Sony mount. So I am not sure how this can work. Is there such an aperture control adapter from an e mount to an e mount? If not, is there anything else I can do?
Thanks,
Charles |
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kds315*
Joined: 12 Mar 2008 Posts: 16497 Location: Weinheim, Germany
Expire: 2021-03-09
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Posted: Tue Feb 11, 2020 9:02 am Post subject: Re: Aperture Control Adapter Question |
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kds315* wrote:
charley5 wrote: |
Hi Everyone:
I just purchased a Rodenstock Heligon 95mm f0.95 projector lens for a Sony mount, to be used on my Sony A7ii. The lens however is a little soft wide open, so I thought to get an aperture control adapter. I am hoping to increase sharpness and eliminate a little vignetting on my full frame camera. The aperture control adapters I have seen all seem to work from a different mount (such as Canon) to the Sony mount. So I am not sure how this can work. Is there such an aperture control adapter from an e mount to an e mount? If not, is there anything else I can do?
Thanks,
Charles |
Welcome Here Charles!
I have done similar, but be advised that rear mounted apertures often lead to (severe) vignetting, so the better solution would be a front aperture, even a simple cardboard one would do... _________________ Klaus - Admin
"S'il vient a point, me souviendra" [Thomas Bohier (1460-1523)]
http://www.macrolenses.de for macro and special lens info
http://www.pbase.com/kds315/uv_photos for UV Images and lens/filter info
https://www.flickr.com/photos/kds315/albums my albums using various lenses
http://photographyoftheinvisibleworld.blogspot.com/ my UV BLOG
http://www.travelmeetsfood.com/blog Food + Travel BLOG
https://galeriafotografia.com Architecture + Drone photography
Currently most FAV lens(es):
X80QF f3.2/80mm
Hypergon f11/26mm
ELCAN UV f5.6/52mm
Zeiss UV-Planar f4/60mm
Zeiss UV-Planar f2/62mm
Lomo Уфар-12 f2.5/41mm
Lomo Зуфар-2 f4.0/350mm
Lomo ZIKAR-1A f1.2/100mm
Nikon UV Nikkor f4.5/105mm
Zeiss UV-Sonnar f4.3/105mm
CERCO UV-VIS-NIR f1.8/45mm
CERCO UV-VIS-NIR f4.1/94mm
CERCO UV-VIS-NIR f2.8/100mm
Steinheil Quarzobjektiv f1.8/50mm
Pentax Quartz Takumar f3.5/85mm
Carl Zeiss Jena UV-Objektiv f4/60mm
NYE OPTICAL Lyman-Alpha II f1.1/90mm
NYE OPTICAL Lyman-Alpha I f2.8/200mm
COASTAL OPTICS f4/60mm UV-VIS-IR Apo
COASTAL OPTICS f4.5/105mm UV-Micro-Apo
Pentax Ultra-Achromatic Takumar f4.5/85mm
Pentax Ultra-Achromatic Takumar f5.6/300mm
Rodenstock UV-Rodagon f5.6/60mm + 105mm + 150mm
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charley5
Joined: 11 Feb 2020 Posts: 346 Location: India
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Posted: Tue Feb 11, 2020 11:53 pm Post subject: aperture control mechanism... a no go! |
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charley5 wrote:
This article basically smashes my idea about installing an aperture control mechanism either in front of or behind the lens. Either way the resulting vignetting is unacceptable.
https://www.davidkennardphotography.com/blog/1076-adding-an-aperture-to-an-irisless-lens.xhtml |
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kds315*
Joined: 12 Mar 2008 Posts: 16497 Location: Weinheim, Germany
Expire: 2021-03-09
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Posted: Wed Feb 12, 2020 12:20 am Post subject: Re: aperture control mechanism... a no go! |
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kds315* wrote:
Well, it massively depends on the focal length and speed of th elens used; loger focal lengths tenfs to much less vignetting.
I woudl try a front cardboard "iris" an see what it does...not much effort. _________________ Klaus - Admin
"S'il vient a point, me souviendra" [Thomas Bohier (1460-1523)]
http://www.macrolenses.de for macro and special lens info
http://www.pbase.com/kds315/uv_photos for UV Images and lens/filter info
https://www.flickr.com/photos/kds315/albums my albums using various lenses
http://photographyoftheinvisibleworld.blogspot.com/ my UV BLOG
http://www.travelmeetsfood.com/blog Food + Travel BLOG
https://galeriafotografia.com Architecture + Drone photography
Currently most FAV lens(es):
X80QF f3.2/80mm
Hypergon f11/26mm
ELCAN UV f5.6/52mm
Zeiss UV-Planar f4/60mm
Zeiss UV-Planar f2/62mm
Lomo Уфар-12 f2.5/41mm
Lomo Зуфар-2 f4.0/350mm
Lomo ZIKAR-1A f1.2/100mm
Nikon UV Nikkor f4.5/105mm
Zeiss UV-Sonnar f4.3/105mm
CERCO UV-VIS-NIR f1.8/45mm
CERCO UV-VIS-NIR f4.1/94mm
CERCO UV-VIS-NIR f2.8/100mm
Steinheil Quarzobjektiv f1.8/50mm
Pentax Quartz Takumar f3.5/85mm
Carl Zeiss Jena UV-Objektiv f4/60mm
NYE OPTICAL Lyman-Alpha II f1.1/90mm
NYE OPTICAL Lyman-Alpha I f2.8/200mm
COASTAL OPTICS f4/60mm UV-VIS-IR Apo
COASTAL OPTICS f4.5/105mm UV-Micro-Apo
Pentax Ultra-Achromatic Takumar f4.5/85mm
Pentax Ultra-Achromatic Takumar f5.6/300mm
Rodenstock UV-Rodagon f5.6/60mm + 105mm + 150mm
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charley5
Joined: 11 Feb 2020 Posts: 346 Location: India
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Posted: Wed Feb 12, 2020 1:23 am Post subject: Front-end aperture control. |
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charley5 wrote:
I see. Thanks Klaus. I shall give it a try then. Stopping down at either end didn't seem to affect sharpness. But I have nothing to lose. |
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visualopsins
Joined: 05 Mar 2009 Posts: 10463 Location: California
Expire: 2021-06-22
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Posted: Wed Feb 12, 2020 2:57 am Post subject: Re: aperture control mechanism... a no go! |
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visualopsins wrote:
Garbage in garbage out. Front of lens aperture extends too far in front of lens' front element acts more like too long hood when closed down thus vignette, however increase in dof is apparent, i.e. front aperture works, rear no. Aperture closer to front element less vignette. _________________ ☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮ like attracts like! ☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮
Cameras: Sony A7Rii, Spotmatics II, F, and ESII, Nikon P4
M42 Asahi Optical Co., Lenses:
Takumar 1:4 f=35mm, 1:2 f=58mm (Sonnar), 1:2.4 f=58mm (Heliar), 1:2.2 f=55mm (Gaussian), 1:2.8 f=105mm (Model I), 1:2.8/105 (Model II), 1:5.6/200
Tele-Takumar 1:5.6/200, 1:6.3/300
Macro-Takumar 1:4/50
Auto-Takumar 1:2.3 f=35, 1:1.8 f=55mm, 1:2.2 f=55mm
Super-TAKUMAR 1:3.5/28 (fat), 1:2/35 (Fat), 1:1.4/50 (8-element),
Super-Multi-Coated Fisheye-TAKUMAR 1:4/17
Super-Multi-Coated TAKUMAR 1:4.5/20, 1:3.5/24, 1:3.5/28, 1:2/35, 1:3.5/35, 1:1.8/85, 1:1.9/85 1:2.8/105, 1:3.5/135, 1:2.5/135 (II), 1:4/150, 1:4/200, 1:4/300, 1:4.5/500
Super-Multi-Coated Macro-TAKUMAR 1:4/50, 1:4/100
Super-Multi-Coated Bellows-TAKUMAR 1:4/100
SMC TAKUMAR 1:1.4/50, 1:1.8/55
Other lenses:
Carl Zeiss Jena Flektogon 2.4/35
SMC PENTAX ZOOM 1:3.5 35~105mm, SMC PENTAX ZOOM 1:4 45~125mm
Nikon Micro-NIKKOR-P-C Auto 1:3.5 f=55mm, NIKKOR-P Auto 105mm f/2.5 Pre-AI (Sonnar), Micro-NIKKOR 105mm 1:4 AI, NIKKOR AI-S 35-135mm f/3,5-4,5
Tamron SP 17mm f/3.5 (51B), Tamron SP 17mm f/3.5 (51BB), SP 500mm f/8 (55BB), SP 70-210mm f/3.5 (19AH)
Vivitar 100mm 1:2.8 MC 1:1 Macro Telephoto
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DConvert
Joined: 12 Jun 2010 Posts: 901 Location: Essex UK
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Posted: Wed Feb 12, 2020 9:58 am Post subject: Re: Aperture Control Adapter Question |
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DConvert wrote:
kds315* wrote: |
I have done similar, but be advised that rear mounted apertures often lead to (severe) vignetting, so the better solution would be a front aperture, even a simple cardboard one would do... |
I've used black paper ones on my 50/1.2 projector & tested them on a couple of others. Made so they fit tight up against the front element, plain circular cut outs work in a similar way to an Iris at least if you get the hole sizes right. Using different shaped cut outs allows you to shape the bokeh too!
Like this: https://flic.kr/p/27KRhGp
On another occasion I tried a large iris held as close as possible to the lens. It worked for some of my projector lenses but others had front elements that where recessed to far giving rise to vignetting. I've not tried the iris since. |
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charley5
Joined: 11 Feb 2020 Posts: 346 Location: India
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Posted: Fri Feb 14, 2020 3:20 am Post subject: Re: aperture control mechanism... a no go! |
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charley5 wrote:
visualopsins wrote: |
Garbage in garbage out. Front of lens aperture extends too far in front of lens' front element acts more like too long hood when closed down thus vignette, however increase in dof is apparent, i.e. front aperture works, rear no. Aperture closer to front element less vignette. |
Thanks. That's helpful! |
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charley5
Joined: 11 Feb 2020 Posts: 346 Location: India
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Posted: Fri Feb 14, 2020 3:26 am Post subject: Re: Aperture Control Adapter Question |
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charley5 wrote:
DConvert wrote: |
kds315* wrote: |
I have done similar, but be advised that rear mounted apertures often lead to (severe) vignetting, so the better solution would be a front aperture, even a simple cardboard one would do... |
I've used black paper ones on my 50/1.2 projector & tested them on a couple of others. Made so they fit tight up against the front element, plain circular cut outs work in a similar way to an Iris at least if you get the hole sizes right. Using different shaped cut outs allows you to shape the bokeh too!
Like this: https://flic.kr/p/27KRhGp
On another occasion I tried a large iris held as close as possible to the lens. It worked for some of my projector lenses but others had front elements that where recessed to far giving rise to vignetting. I've not tried the iris since. |
Does it help shape highlights in the background, as you imply on your page? Did you find it sharpened the image a bit as well, given that the aperture was wide open?
Thanks. |
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DConvert
Joined: 12 Jun 2010 Posts: 901 Location: Essex UK
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Posted: Fri Feb 14, 2020 8:22 am Post subject: Re: Aperture Control Adapter Question |
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DConvert wrote:
charley5 wrote: |
DConvert wrote: |
kds315* wrote: |
I have done similar, but be advised that rear mounted apertures often lead to (severe) vignetting, so the better solution would be a front aperture, even a simple cardboard one would do... |
I've used black paper ones on my 50/1.2 projector & tested them on a couple of others. Made so they fit tight up against the front element, plain circular cut outs work in a similar way to an Iris at least if you get the hole sizes right. Using different shaped cut outs allows you to shape the bokeh too!
Like this: https://flic.kr/p/27KRhGp
On another occasion I tried a large iris held as close as possible to the lens. It worked for some of my projector lenses but others had front elements that where recessed to far giving rise to vignetting. I've not tried the iris since. |
Does it help shape highlights in the background, as you imply on your page? Did you find it sharpened the image a bit as well, given that the aperture was wide open?
Thanks. |
Yes the OOF highlights take on the shape of the cutout (as shown by the flowers in the linked picture). I couldn't manage shot without the bokeh masks as it was too bright for f/1.2 even at my lowest ISO and I didn't have an ND filter with me, but from the rules of Physics yes it will sharpen up the image/increase DOF. It is possible to make masks that allow light from the outer edges of the lens while blocking the centre portion - those will give a soft focus effect - though I've not done one personally. |
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charley5
Joined: 11 Feb 2020 Posts: 346 Location: India
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Posted: Sat Feb 15, 2020 11:17 am Post subject: Re: Aperture Control Adapter Question |
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charley5 wrote:
charley5 wrote: |
Hi Everyone:
I just purchased a Rodenstock Heligon 95mm f0.95 projector lens for a Sony mount, to be used on my Sony A7ii. The lens however is a little soft wide open, so I thought to get an aperture control adapter. I am hoping to increase sharpness and eliminate a little vignetting on my full frame camera. The aperture control adapters I have seen all seem to work from a different mount (such as Canon) to the Sony mount. So I am not sure how this can work. Is there such an aperture control adapter from an e mount to an e mount? If not, is there anything else I can do?
Thanks,
Charles |
Would a focal reducer decrease the risk of vignetting? |
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DConvert
Joined: 12 Jun 2010 Posts: 901 Location: Essex UK
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Posted: Sat Feb 15, 2020 1:00 pm Post subject: Re: Aperture Control Adapter Question |
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DConvert wrote:
charley5 wrote: |
charley5 wrote: |
Hi Everyone:
I just purchased a Rodenstock Heligon 95mm f0.95 projector lens for a Sony mount, to be used on my Sony A7ii. The lens however is a little soft wide open, so I thought to get an aperture control adapter. I am hoping to increase sharpness and eliminate a little vignetting on my full frame camera. The aperture control adapters I have seen all seem to work from a different mount (such as Canon) to the Sony mount. So I am not sure how this can work. Is there such an aperture control adapter from an e mount to an e mount? If not, is there anything else I can do?
Thanks,
Charles |
Would a focal reducer decrease the risk of vignetting? |
No it will definitely make it MUCH worse. A smaller aperture as Charles was suggesting can improve a lenses coverage and will certainly help with vignetting if it's in the right place. In the wrong place an added aperture can make vignetting worse. |
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philslizzy
Joined: 07 Aug 2012 Posts: 4747 Location: Cheshire, England
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Posted: Sun Mar 15, 2020 1:52 pm Post subject: |
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philslizzy wrote:
Most projector lenses have the rear element way up the barrel. Perhaps a cut aperture pushed up against the rear lens will work _________________ Hero in the 'messin-with-cameras-for-the-hell-of-it department'. Official. |
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