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RioRico
Joined: 12 Mar 2010 Posts: 1120 Location: California or Guatemala or somewhere
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Posted: Thu Dec 22, 2011 6:07 am Post subject: next dumb question: fractional dioptre add-on lenses? |
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RioRico wrote:
I'm a perv. I like front-mounted optical strap-ons, like filters, wide+tele adaptors, and +dioptre meniscus lenses, as well as Raynox adapters. A +1dpt lens changes the focal length of the combined optic slightly, but shifts the working distance down to 50-95cm, with reduced DOF. I estimate that a +0.5dpt lens would have a working distance somewhere around 90-160cm, far enough for headshot portraiture. Even a modestly slow lens should have rather thin DOF. But I can't find any. Does anyone here know of suppliers for +0.5dpt screw-ons? _________________ Too many film+digi cams+lenses, oh my -- Pentax K20D, K-1000, M42s, more
The simple truth is this: There are no neutral photographs. --F-Stop Fitzgerald |
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GrahamNR17
Joined: 17 Jan 2009 Posts: 1855 Location: Norfolk, UK
Expire: 2012-09-06
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Posted: Thu Dec 22, 2011 7:37 am Post subject: |
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GrahamNR17 wrote:
I share your perversion
For wide or tele adaptors, take a look at the Olympus add-ons they made for the iS/L cameras - they're probably the best available, ditto the similar items from Kodak, Panasonic and Fuji. On my little digital, they're sharp to the edges Not so brilliant on full-frame 35mm, but more than acceptable. The Chinese stuff on ebay is universally crap
As for close-ups, I've never seen a +0.5. How about one of those really pervy "zoom" close-ups made by Hoya in the 70s and 80s? I have one, but never really put it through its paces. |
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Minolfan
Joined: 30 Dec 2008 Posts: 3438 Location: Netherlands
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Posted: Thu Dec 22, 2011 8:19 am Post subject: |
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Minolfan wrote:
I found a list: http://fuzzcraft.com/achromats.html
Only a Pentax 0.44 in your range. And I think it is not easy to find one in real life. Cannot you ask you optician to put a glass fot spectacles in an old filter frame? Should not be too expensive. No nice achromat to get so, ofcourse.
I use a Minolta achromat 1 (0.94) on 85 - 135mm lenses, works certainly pleasant. Got it (like) new in original packing for € 2.50 in a box for sale in a photoshop |
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kds315*
Joined: 12 Mar 2008 Posts: 16641 Location: Weinheim, Germany
Expire: 2021-03-09
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Posted: Thu Dec 22, 2011 8:37 am Post subject: |
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kds315* wrote:
Yes, I have a 0.4 diopter in 72mm diameter if you need one. _________________ 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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Sevo
Joined: 22 Aug 2008 Posts: 1189 Location: Frankfurt, Germany
Expire: 2012-12-03
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Posted: Thu Dec 22, 2011 10:27 am Post subject: |
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Sevo wrote:
I have a 67mm 0.5dpt Heliopan Achromat. Sub 1dpt achromats in big diameters weren't altogether uncommon up to about 30 years ago, as conventionally designed long lenses (upward of 250mm) generally were limited in close focus to some 2-5m, due to the weight/stability trade-off of long-throw helicals. Zooms and internal focusing later moved the close range in and killed that niche.
But small diameter dioptres in values below 1dpt might be much rarer, if they exist at all - even close range challenged systems had their normal lens close limit at or below 1m, and the bulk of SLR lenses went down to 0.7-0.3m, so that the appropriate dioptre starting value would be 1dpt at the very least. _________________ Sevo |
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kds315*
Joined: 12 Mar 2008 Posts: 16641 Location: Weinheim, Germany
Expire: 2021-03-09
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Posted: Thu Dec 22, 2011 10:46 am Post subject: |
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kds315* wrote:
Yes indeed, diopters < 1 dpt are pretty rare and hard to find esp. achromats. I have both types in 0.4 dpt. found after some long search. _________________ 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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scsambrook
Joined: 29 Mar 2009 Posts: 2167 Location: Glasgow Scotland
Expire: 2011-11-18
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Posted: Thu Dec 22, 2011 1:12 pm Post subject: |
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scsambrook wrote:
Fractional diopter lenses in diameters 55mm or larger were supplied by some makers in the 1970s, usually for their zoom lenses which had closest focus distances that were anything but close. I have +0.5d made by Sun, which going by its thickness must be an achromat. It works okay. Kodak also made them for the 135 Retina Tele Xenar, designated NI and NII. They sometimes turn up on eBay, which is where I got my pair.
The optician is a good idea, but it might not be cheap. I recently checked this in connection with another hare-brained idea of mine. The man said £20+ VAT = £24 for a disk up to 60mm diameter and that was plastic not glass. Maybe not the way to get really high quality. _________________ Stephen
Equipment: Pentax DSLR for casual shooting, Lumix G1 and Fuji XE-1 for playing with old lenses, and Leica M8 because I still like the optical rangefinder system. |
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RioRico
Joined: 12 Mar 2010 Posts: 1120 Location: California or Guatemala or somewhere
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Posted: Fri Dec 23, 2011 11:01 am Post subject: |
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RioRico wrote:
Thanks for the responses! Part of my reason for inquiring is that I recommend odd stuff on various forums, and a source of inexpensive <+1dpt magnifiers would be handy. But if none such exists... well, that's life. The article I'm writing on STUFF TO PUT IN FRONT OF YOUR LENS will have a hole in it.
@Graham,
Thanks for the Olympus-Kodak-Panasonic-Fuji recommendations. Yes, I skip the cheap Chinese strap-ons. My best now are Sony and Kowa.
@Minolfan,
Thanks for the list of achormats. And I've been hunting for round spectacles but even odd-shaped ones might work (jammed into adapter rings and masked) if they're large enough. Maybe I'll sacrifice some of my old glasses.
@Klaus,
Thanks for the offer. What were you thinking as to price? Hmmm, but shipping from Germany to California might be costly...
@sevo,
Large ones existed more recently too. I had a Tamron AF AL 28-200, probably 15 years old. It included a 72mm close-up, I think just +1dpt, that I sold with the lens. Didn't think I'd need to keep it.
@Stephen,
You're right, an optician wouldn't be cheap. I thought to ask a glass shop if they could cut down welder's glass for a ND666 filter; maybe they'd do spectacles too? _________________ Too many film+digi cams+lenses, oh my -- Pentax K20D, K-1000, M42s, more
The simple truth is this: There are no neutral photographs. --F-Stop Fitzgerald |
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aoleg
Joined: 22 Feb 2008 Posts: 1387 Location: Berlin, DE
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Posted: Sat Dec 24, 2011 4:02 am Post subject: |
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aoleg wrote:
I have a Pentax T160 attachment in 52mm filter size. It's SMC coated, about 0.625 dioptres (ref. http://kmp.bdimitrov.de/misc/macro/index.html). Used with SMC Pentax 85/1.8, it allows focusing a little closer for those face-only portrait shots. _________________ List of lenses |
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RioRico
Joined: 12 Mar 2010 Posts: 1120 Location: California or Guatemala or somewhere
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Posted: Thu Dec 29, 2011 8:52 am Post subject: |
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RioRico wrote:
At the other end of the dioptre range, I just won a +20dpt close-up strap-on. I'm not expecting much in the way of IQ from it, but it's cheap at US$9 shipped. Maybe it will arrive before I go traveling; maybe not, and I'll have to stack two +10dpt pieces.
You may wonder, why bother? Well, they're fun and cheap and small. And something funny happens when +20dpt is stacked onto a +8dpt Raynox DCR-250: it becomes a roughly 35mm f/0.95 frankenlens. Put a 42-41mm step-down ring on the Raynox, then an M42 adapter, then onto the camera -- nothing faster! Horrible aberrations, of course.
ObTopic: I'm ready to sacrifice old eyeglasses to make a fractional dioptre lens. But I guess I can't advise newbs to do so, to turn their kit lenses into portrait marvels. Ah well... _________________ Too many film+digi cams+lenses, oh my -- Pentax K20D, K-1000, M42s, more
The simple truth is this: There are no neutral photographs. --F-Stop Fitzgerald |
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Minolfan
Joined: 30 Dec 2008 Posts: 3438 Location: Netherlands
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Posted: Thu Dec 29, 2011 9:01 am Post subject: |
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Minolfan wrote:
Doesn't come out something interesting glass when you dismantle a stuck zoomlens?
I have a AF Sigma 70-300mm that doesn't work anymore. No idea what is in it |
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RioRico
Joined: 12 Mar 2010 Posts: 1120 Location: California or Guatemala or somewhere
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Posted: Thu Dec 29, 2011 9:11 am Post subject: |
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RioRico wrote:
Minolfan wrote: |
Doesn't come out something interesting glass when you dismantle a stuck zoomlens?
I have a AF Sigma 70-300mm that doesn't work anymore. No idea what is in it |
Hmmm, I haven't tried that, mainly because I don't have any junked zooms to play with. Do zooms contain fractional dioptre elements? _________________ Too many film+digi cams+lenses, oh my -- Pentax K20D, K-1000, M42s, more
The simple truth is this: There are no neutral photographs. --F-Stop Fitzgerald |
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Sevo
Joined: 22 Aug 2008 Posts: 1189 Location: Frankfurt, Germany
Expire: 2012-12-03
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Posted: Thu Dec 29, 2011 12:41 pm Post subject: |
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Sevo wrote:
RioRico wrote: |
Hmmm, I haven't tried that, mainly because I don't have any junked zooms to play with. Do zooms contain fractional dioptre elements? |
Optically yes, but they probably won't exist as a isolated element - and asymmetric elements (e.g. +0.3/-1.25) can't be split to use only one half... _________________ Sevo |
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