inglis wrote:
hmm, looks like the protrusion on the Nikon F 20/2.8 AI-S pushes the canon ef contacts down.
Nikon 20mm 2.8 via Canon SB on 5n,
When designing the Speed Booster we checked several dozen Nikon lenses for interference, including 35/1.4 AIS, 28/2.0 AIS, 28/3.5 AI, 24/2.0 AIS, 24/2.8 AIS, 16/3.5 AI'd, 15/3.5 AI, *and* 20/2.8 AFD. We only discovered the 20/2.8 AIS interference issue about a week ago. Groan!
philber wrote:
Very impressive stuff, LG! One small question. When you say @f:1.4, does that mean wide open, which, with the SpeedBooster means f:1.2, or a real f:1.4, meaning stopped down 1 stop?
Brain, It is really great to see SB designer here. a awesome product.
Any comment about Leica R comparability? Should Metabone at least put some caution on their Leica R SB or some illustration to avoid potential damage of SB glass by unaware of Leica R users?
zhangyue wrote:
Brain, It is really great to see SB designer here. a awesome product.
Any comment about Leica R comparability? Should Metabone at least put some caution on their Leica R SB or some illustration to avoid potential damage of SB glass by unaware of Leica R users?
Thanks!
Metabones does list the Leica-R lenses with known mechanical interference issues on their website:
these are:
Super-Elmar-R 15mm
Elmarit R 28/2.8
Elmarit R 35/2.8
Summicron R 50/2
As far as I am aware, it is only bits of metal that are interfering, and not glass, so modification is possible.
Thanks for the feedback. As far as I know, there are at least 35lux r and 35cron r will have issue. Put unfinished list is even more dangerous since user may just use whatever R lens not on the list then found out that cause damaging SB.
...since it is confusing to compute the 35mm equivalent parameters I always use the 35mm adjustments, means:
35mm 1.4 on the Distagon ! (the lens is the reference)
(would be 35mm/1.5 and 1.4/1.5 on NEX-6)
(would be 35mm / 1.07 and 1.4/1.07 on SB on NEX-6)
best, L.
I'm not quite understanding you here.
A 35mm f/1.4 lens plus the Speed Booster becomes a 25mm f/1.0 lens, pure and simple. Its virtually identical to the Voigtlander 25/0.95 and except that it covers a much larger format (DX vs 4/3).
brianc1959 wrote:
I'm not quite understanding you here.
A 35mm f/1.4 lens plus the Speed Booster becomes a 25mm f/1.0 lens, pure and simple. Its virtually identical to the Voigtlander 25/0.95 and except that it covers a much larger format (DX vs 4/3).
...sorry, my part is hardly to understand and partially wrong
35/1.5 *1.07= 25 mm lens with 1.4/1.5 *1.07= 1.0 aperture if you like to get a native NEX-lens (on crop factor 1.5)
but also
35 * 1.07 = 37.5 mm lens with 1.4 * 1.07 = 1.5 aperture with respect to a FF sensor.
brianc1959 wrote:
A 35mm f/1.4 lens plus the Speed Booster becomes a 25mm f/1.0 lens, pure and simple. Its virtually identical to the Voigtlander 25/0.95 and except that it covers a much larger format (DX vs 4/3).
So even the DOF increases a stop? Or is it just light gathering ability? I've never fully read the white paper, I just like to buy things. haha
I do wonder whether wide ZM and Contax G lens will work on a future full frame Nex all the way to the corners. From reports on the VG900, this sounds possible. Otherwise a Nex crop camera and a speed booster is a great way to go, in order to use SLR lenses close to FF, and ZMs and Contax Gs on crop.
zhangyue wrote:
Thanks for the feedback. As far as I know, there are at least 35lux r and 35cron r will have issue. Put unfinished list is even more dangerous since user may just use whatever R lens not on the list then found out that cause damaging SB.
Yes, almost all R lenses will need to be modified in order to use on the SB I believe.
It's fairly simple though, all you have to do is shave down the metal piece protruding from the rear element about 50-60%, then you'll be all set.
Also, I'm fairly certain the metal piece doesn't really touch the Speed Booster glass (well not on the Summicron 35/2) but comes dangerously close to it.
It does make contact with something that doesn't allow for focus to infinity either way.
I'm strapped for cash at the moment, but I'm enjoying the 35/2 so much, I plan on getting a couple R lenses to use with the Speed Booster this summer.
The Summicron works really well at close focus distances from what I can tell.
I'm thinking the 28/2.8, 50/1.4, and 80/1.4 for a full line up eventually.
Brody LeBlanc wrote:
I'm thinking the 28/2.8, 50/1.4, and 80/1.4 for a full line up eventually.
Good to know about it won't hurt lens. If you don't want break the bank, try 50cron first. It is a very small lens, fit well on SB and super sharp at f2.8, sharp at f2. With that amount of R lens in your list, you will go back to DSLR sooner or later
zhangyue wrote:
Good to know about it won't hurt lens. If you don't want break the bank, try 50cron first. It is a very small lens, fit well on SB and super sharp at f2.8, sharp at f2. With that amount of R lens in your list, you will go back to DSLR sooner or later
lol! funny you mention that, I'm considering buying my friends D700 as a backup to my X-Pro1.
Now wouldn't that be backwards as hell? lol.
Truth be told, out of all my old digitals, the D700 has a place somewhere in my heart still.
Oh and just use a file intended for sharpening/filing. They can be found at basically any hardware store.
Mine looks like this.
Just be careful if you're going to attempt this.
The metal "dust" that will collect as you file the protruding piece down is pretty annoying and will want to stick to everything.
Make sure the rear of the lens aside from that piece is completely covered.
The last thing you want is a shiny metal spec stuck under the rear element.
Also, shave it down at an angle away from the rear element, obviously hitting the element would be a bad idea!
For the record, all the SLR lenses that I own pass the SB 'clearance' test without requiring surgery. No, not Leica-R lenses, just a Macro Svitar 50/1,9 (Alpa mount), a Super Takumar 35/3.5 (M42) and a couple of Tamron MF zooms (a 35-80/2.8-3.8 and a 70-210/3.8-4 ) with Nikon F Adaptall mount.
I have to say though, that the rear part of the Svitar 50, when focused at infinity, comes frightfully close to the Speed Booster front lens.
GrevGrev wrote:
So even the DOF increases a stop? Or is it just light gathering ability? I've never fully read the white paper, I just like to buy things. haha
Short answer: you are getting more-or-less the same depth-of-field as on a full-frame camera.
Long answer: very complicated. We have to state every assumption clearly. Depth of field depends on magnification (which in turn depends on focal length and distance), f-stop and circle of confusion. A 25mm lens is a completely different lens from 35mm in terms of perspective, so do we keep focusing distance the same? Or do we keep magnification the same? Also some people would choose a smaller circle of confusion for APS-C than for full frame, but other people may not agree. Depending on how you choose the assumptions we could arrive at completely different answers.
Don't worry if you don't like the long answer, however, just stick with the short one: SB gives DoF roughly equivalent to full frame, which is shallower than without SB.
Yeah, I was assuming all variables are constant for both while examing the DOF. But the train of thought is... a smaller projected circle on the same surface area will need more magnification to get the same framing as a straight APS-C sensor, therefore, the DOF would behave like a full frame sensor.
Meanwhile I have tried the Speed Booster with most of my lenses, even the most extreme corners are fairly good at wide open with my lenses. And no photos yet, still very busy with full time work and full time study, will be able to take some photos for next weekend though.
PS I'm also going to try my AFS 35mm f1.8 on it to see how it peforms, that lens worked fine with slight vignetting on my D700 so this should be very interesting.
