Brian Caldwell

On 4/15/2016 at 2:52 AM, AaronChicago said:

Brian, I actually did use this combo with the FS700 and loved it. I'm using the Ursa mini 4.6k now and have to attach via EF.

Sorry - I overlooked the EF camera mount restriction.  I hope Canon, Blackmagic, etc. will wake up one day and do the straightforward engineering needed to fix this.

9 hours ago, AaronChicago said:

I wish they'd make a non servo version of an 18-80. f4 doesn't bother me for a zoom lens. I love using the 24-105 but I find myself wishing it had a slightly wider low end.

Just add a 0.71x SB to your 24-105 and you have a 17-75mm f/2.8

28 minutes ago, richg101 said:

Tell me about it! - the design and manufacturing of the focus mechanism for such a badboy has been a task.  it uses both a beautiful brass helical and a system of rollers / bearings to alleviate droop due to the weight of the huge pieces of glass.  

   

 

That's *really* big!

5 hours ago, richg101 said:

OLIVIA Scope was originally going to be a straight clone of an iscorama, just scaled up.  It soon became clear that in order to make something really groundbreaking we had to start out with a blank canvas.  Though OLIVIA Scope is operated in the same way as an Iscorama, because of the wide fov capability a racking adjustable diopter type 'untactful isco copy' focus mechanism would need a ridiculously over-engineered helical to provide shift of a big diopter element.      

 

If you're doing a wide angle Iscorama-style attachment with a large diameter front, then my statement about the variable diopter being "easy" obviously needs amendment, since the mechanics does become much more difficult.  Although I'm a big fan of big lenses, they tend to require exotic/expensive items like precision linear bearings to keep them moving straight and without play.

Maybe not entirely relevant here, but its interesting the the new Cooke anamorphics also use a pretty basic variable diopter focusing scheme, although the net power is negative rather than afocal:  http://pdfaiw.uspto.gov/.aiw?PageNum=0&docid=20140300973&IDKey=735679DAC5C4&HomeUrl=http%3A%2F%2Fappft.uspto.gov%2Fnetacgi%2Fnph-Parser%3FSect1%3DPTO2%2526Sect2%3DHITOFF%2526p%3D1%2526u%3D%25252Fnetahtml%25252FPTO%25252Fsearch-bool.html%2526r%3D5%2526f%3DG%2526l%3D50%2526co1%3DAND%2526d%3DPG01%2526s1%3Diain.IN.%2526s2%3Dneil.IN.%2526OS%3DIN%2Fiain%252BAND%252BIN%2Fneil%2526RS%3DIN%2Fiain%252BAND%252BIN%2Fneil

3 hours ago, tweak said:

The main thing to consider is that there was almost no demand for a product like this pre indi anamorphic revival. 

The other thing is that this type of thing did exist before, just in a slightly different form. If you go online you can find many variable diopters for close up macro work, the thing being that these type of attachments were usually made cheaply and thus produced average results. I assume that many people thought that this meant that variable diotpers in front of lenses would be a bad idea just as a generalisation. It took John Barlow (Rectilux) to re-invision the idea and create something of worth, if it wasn't for this I'm sure people would still think it's a bad idea.

FM and SLR RF seem like solutions with many compromises, whilst Rectilux seems to deliver what everyone is after, the price difference speaks for itself.
 

I think the death of anamorphic film projection and the resulting appearance of dirt cheap anamorphic projection lenses (e.g. Schneider Cinelux etc.) was also an important factor.  After all, the variable diopter part is easy, its the cylindrical lenses that are hard to make.  It will be interesting to see what happens once the supply of grossly underpriced projection lenses dries up.

3 hours ago, Tito Ferradans said:

A little more about them here - http://www.tferradans.com/blog/?p=8462

I think it was a matter of insight (realizing that the focus solution didn't need to be associated with an anamorphic directly in a complete system, against the Isco patent) and time to develop.

Note, at the time the Isco patent was issued in 1970 the law was that the lifetime of a patent was 17 years from the date of issue.  When a patent expires the time-limited right of the assignee to a monopoly also expires, and the technology becomes part of the public domain.  So, its been completely legal to manufacture and sell Iscorama style systems since 1987, almost 30 years now!

As long as you use a fullframe (24x36mm format) master lens, then both the 0.71x ULTRA and 0.64x XL will work fine.  The ULTRA is a little better corrected in the outer part of the image, but this is mainly important if you want critically sharp results at f/1.0 with a Sigma ART or Zeiss Otus, and would not be noticeable with a slow lens like the Canon 24-105.  If you plan to use an APS-C lens such as the Canon 17-55/2.8, then you should be aware that you may encounter slight vignetting when shooting HD (not 4k) with the 0.64x XL.  The reason for this is that even though the XL itself covers the entire m43 image just fine, the image circle of the lens is too small to cover after it is multiplied by 0.64.

6 hours ago, Jimmy said:

None that I know of, unless by mirrorless, you are also counting things like BM Ursa?

Can a camera that only offers a EF or PL lens mount truly be considered mirrorless?  True, there is no mirror, but if you throw away the possibility of short BFL optics what is the point?

56 minutes ago, BrooklynDan said:

The G 25mm does have distortion, but relatively speaking, it's much straighter than comparable lenses from other manufacturers. It's definitely better than any of the wide-angle Lomos. The 25mm Hawk V-series is nearly unusable, and the various Shiga-based squarefronts from JDC, Cineovision and others don't fare much better. The Elite 24.5 is decent but suffers from breathing and mumping.

Cooke 25mm can be seen here:

https://vimeo.com/152621245

It still has the pin-cushion distortion that the Anamorphic/i series is unfortunately known for, but to my eyes, it's less prominent than on the 32mm. Actually a pretty decent lens in my opinion.

Hi Dan:

Thanks for the info!  My only point of reference was the Panavision 25mm, and it definitely seemed like a lot of distortion to me.  Very interesting to learn that Hawk and others are worse.

On 3/21/2016 at 4:24 PM, BrooklynDan said:

I think that in order to play with the big boys, you gotta cost like the big boys. There is no simple way to build 2x anamorphic primes that have any decent quality for much less than what they already cost. The 1.33x lenses look pretty good for the money, but still have considerable distortion, softness around the edges and chromatic aberration that wouldn't hold up on anything resembling a big screen.

And forget about ever seeing a decently priced super-wide-angle anamorphic prime lens. The only really good ones I've seen are the Panavision G-series 25mm and the new Cooke 25mm. The rest suffer from severe barrel distortion and breathing. Building a good wide-angle anamorphic lens is one of the most difficult assignments that a lens engineer could ever receive.

The Panavision G 25mm does have severe barrel distortion.  I haven't seen the new Cooke 25mm yet - does it have the same weird mix of pincushion and barrel distortion that the other Cooke anamorphics have?

42 minutes ago, bluefonia said:

Yes, I use speed boosters (on Panasonic GH4) and I was aware of the focus issues these can cause at infinity, so I made the test without speedbooster.

Anyways, - as you can see from the post above - there is nothing wrong with the lens, it simply comes down to the way it is constructed.

The linear portion non-parfocal behavior can be fixed with a back focus adjustment.  This is easy to do with a Speed Booster.  With a plain adapter you'll have to luck out and be able to do it by shimming the flange instead of having to remove metal.  This will give the long and short focal length positions the same focal position.  What happens in-between is the non-linear portion, and is controlled by the cam that moves the compensating lens group inside the lens.  If you have a significant lack of parfocality in the in-between region the standard way of fixing it is to re-machine the compensator cam, but only super high-end cine lenses get this treatment.

3 hours ago, TSV said:

Hi

I was shooting (a few hours a go) some landscape including Mt Fuji and tea fields 

But! I have some really bad heat haze over the green tea fileds, how to deal with that in general?

Cheers

Not sure if any of this will help in your situation, but try keeping the focal length as short as possible, using the smallest feasible aperture (note that diffraction may not be as objectionable compared to image degradation due to heat haze), shoot when the ground and air are close to the same temperature (e.g., at dawn, after a rainstorm, etc.), and maybe try some image stacking/averaging techniques used by amateur astronomers.

7 hours ago, richg101 said:

I have just read the article once again.  And only wish he'd written it a little more concisely.  We don't need mtf charts within a debate of this kind.  it's not about science.  It's about preference.  I prefer lenses designed and made before the digital era since they have been used to capture what I consider the best material.  i see most of what has been produced in the digital age to be far inferior to what was produced before.

One thing i do know is that if you take a picture of someone with a helios 44 or any 6 element 50mm prime from before the 1990's, then the same picture with the sigma art 50/1.4, the person will prefer the image taken with the older lens.  A Sigma Art lens is like the hobbit being filmed/delivered in 48fps.  Both defy a convention that's been built over decades.  24fps look like cinema.  older lenses render an image closer to the look of the proper hollywood days.

 

          

 

I certainly wouldn't argue that old lenses might not be preferable in certain circumstances.  After all, there are a number of cine rental houses that make tons of money from large inventories of vintage glass.  However, the author of the article in question should at least do careful comparisons to make his points, because it seems to me that lighting is the dominant effect that he's demonstrating, not lens differences.  And his attempts to appear scientific by making those ternary charts is just a complete joke.  I'm shocked that so many people on his blog and elsewhere just accept them as having some sort of meaning without questioning.

1 hour ago, richg101 said:

 

If there were indeed 25mm f1.0 lenses for aps-c to replicate a 35mm/1.4 lens on full frame the argument would be viable.  but there is no such lens.  

Any 35/1.4 FF SLR lens plus a 0.71x Speed Booster will give a 25/1.0 for aps-c. 

On 3/14/2016 at 9:48 AM, tweak said:

My main concerns Brian are:

1 - Although a 1.75-1.8x squeeze lens is quite useful and makes sense on paper I feel it may become less useful and more obsolete in the very near future. As Zak Forsman points out, new cameras are coming out all the time with updated ratios and I think it's only a sign of things to come.

2 - Yes consumer cams mostly have 16:9 sensors, with a notable one (GH4) actually having a 4:3 mode, but I honestly feel these people wont be your target market anyway! These are the people that worry about the price difference between an SLR RF vs a Core DNA when the later is only a bit over twice as much but you get way better optics... I don't think many people from that crowd will really be able to afford (or justify) your creations. Thus I don't think it make sense to consider what they would be shooting with. ( I know this because I'm one of them  ).

Personally I'd say stick with 2x stretch and make some lenses that will really stick it to the competition!!!

All the best Brian, keep up the good work!

I appreciate your comments, and you certainly make some valid points.  However, 4:3 will never actually become obsolete as it is always available from 16:9 via cropping.  And a 4:3 crop of 16:9 will always have more pixels than a 6:5 crop.  So, in my view the updated 6:5 ratio is simply a nod to an old (and soon-to-be obsolete?) film standard, and its unlikely to replace the ARRI Alexa 4:3 standard.  After all, the recent explosion in anamorphics used for feature films is largely due to the native 4:3 mode in the Alexa.

Regarding the GH4, you are probably correct regarding the market.  Which is one reason I want to make a lower cost Iscorama-type attachment available.  But the prime lenses I have in mind will be really special, and should appeal to people who view the camera as a small accessory that you attach to your lens rather than the other way around.  Bear in mind that its pretty simple to switch from a PL mount design to m43.

Another little thought:  1.79x on a 1:1 sensor (or a 1:1 crop of a wider sensor) gives you 1.79:1 = 16.11:9.  In other words it gives almost a perfect rectangle for anamorphic HDTV.

On 3/12/2016 at 7:23 PM, SR said:

As much as conciseness is appreciated, we would simply like him to share some of his insight (instead of a dismissal), especially those of us who aren't as experienced with lenses. I think that much is fair in a forum, isn't it?

I probably should have stayed away from this topic, but I found the article so utterly revolting that I just couldn't help myself.  Its difficult to even begin a thorough critique, and I'm not going to do it here.  Suffice to say that he relies almost entirely on non-standard,  non-optical terminology (e.g., 3D, tonality, micro contrast, flat), and he never bothers to define these terms in a precise and unambiguous way.  Lenses can be fully characterized by things that are well-defined and can actually be measured, such as MTF, veiling glare, distortion, transmission vs. wavelength, etc..  Why rely on pseudo-scientific nonsense when proper characterization methods are well established?  He then goes on to show images that supposedly illustrate his points, but none of the images are actually carefully done comparisons under fixed lighting conditions, post processing,  etc., so they are absolutely worthless as far as I'm concerned.  He also makes a bunch of ternary diagrams that make absolutely no sense at all - "line of realism"??? WTF???  And his obsession with the number of elements in a design is absolutely bizzare.

Sorry, but somebody's got to say it.  This has to be the worst piece of trash writing ever done about lenses.  The author has absolutely no clue what he is talking about, and should be ignored.

On 2/25/2016 at 2:24 PM, Timotheus said:

Cool idea. No idea about feasibility though. The designer of the Metabones Speedbooster actually visits this forum: @Brian Caldwell. Perhaps this mention invites him to a reaction ;-)

The main technical hurdle is that focal reducers reduce the physical length of a lens in addition to reducing the focal length.  So if you simply build a focal reducer from cylinders you would wind up with many millimeters of astigmatism throughout the image.  An even bigger concern, as valid points out, is that you don't get any of the desirable anamorphic artifacts with a rear anamorphic attachment. 

2 hours ago, Andrew Reid said:

A rather interesting thread this has been so far. Thanks Brian for the idea.

I have owned the Canon 24-70mm F2.8L II and Tamron 24-70mm, to be honest there's not a lot between them aside from price. The Tamron is certainly very good indeed for the money especially on the Speed Boosters.

The Canon is a tad sharper.

The old Canon 24-70mm F2.8L is a LOT darker wide open than the Tamron and the newer lens, it behaves more like a F3.8

Very nice character though.

Thanks, Andrew.  

The Canon 24-70/2.8II is actually the one that I own, and I like it a lot.  However, I picked the Tamron as an example because it has optical stabilization, which would make up for the shortcoming in the A6300.

1 hour ago, Ebrahim Saadawi said:

@Brian Caldwell

It's an interesting thought.

A Sony/Canon 50mp-ish newest FF sensors + Zeiss/Sigma 50mm F/1.4 glass would provide the same or better image to a 50MP sensor with a common 80-90mm f/2.8. I think it happened because the higher demand on FF warranted higher performance increase both by sensor & lens makers. 

The MF SB request comes from that there's a magical unique aesthetic to MF size but I don't think it's true and matching between size formats has been proven with getting equivalent lenses = same ''aesthetic''. 

And some people argue that MF glass is vastly higher performing and quality built/glass to any FF lenses. I also don't think it's true and only applies to a handful of very expensive and modern MF stills/Cinema glass. FF lenses have rocketed, look at Sigma & Canon & Nikon & ziess newest releases after 2013-ish in terms of IQ and cost, unbelievable.

I certainly agree with both your main points:  1) there is no magical aesthetic to MF, and 2) MF glass is not generally higher performing than FF glass.

The newer Zeiss lenses are just flat-out amazing in terms of IQ, but are expensive (similar to many MF lenses).  The Sigma ART lenses are an amazing blend of high performance at a modest price.  And it does appear that Canon, Nikon, Tamron et al. are starting to catch up.  I think it really is a golden era in photographic optics, but most of the gold is being bestowed on FF rather than MF.

3 hours ago, Ebrahim Saadawi said:

@Brian Caldwell you don't see it because you still haven't created it I guess!

You don't believe medium format lenses have an advantage over FF glass? or just not when speedboosted? (if there's some kind of limitation).

I am sure using ALL THOSE medium format lenses on A7 series cameras with full image would be something people love!

Both.  The problem with medium format lenses is that they are by and large very slow.  As in f/2.8 on the fast side, and often way down around f/3.5-f/4.5, even for prime lenses.  After you add a focal reducer the speed is improved, but still just isn't very exciting.  I know there are a handful of f/1.9 - f/2.0 medium format lenses out there, but performance is not good enough to warrant a special Speed Booster IMO.  By contrast, the latest FF optics by Zeiss, Sigma et al are breathtakingly good at very large apertures.  The older medium format lenses just aren't in the same league, and I doubt there is enough of a market for them to ever catch up.

At one point I thought about doing a Speed Booster for the Leica-S lenses since they're actually pretty good.  However, they're also very expensive and you'd have to reverse-engineer the electronics to control the aperture.

4 hours ago, Ebrahim Saadawi said:

Now we're all waiting for it to do the same to MF & FF  

I just wish there were at least one example of a speedboosted medium format lens that can't be equaled or bettered by a FF lens.  

7 hours ago, conurus said:

The glass element protruding from the rear didn't clear the rectangular baffle of my NEX-7, and the A6300 had a similarly shaped rectangular baffle.

So, does this mean we need to do yet another custom Speed Booster?

3 hours ago, Ebrahim Saadawi said:

The Fuji Cine zoom will most definitely produce better technical IQ and mechanical properties, but with your Speedbooster invention the asked cost is no longer viable now and especially for future products. My Nikon 24-120mm F4 IS + SB gives me a s35 17-90mm F/2.8 IS zoom lens which is not available at any reasonable price bracket south of 50K+ s35 cine zooms.

I'm not entirely sure about the IQ - its something I would want to test.  Its worth noting that inexpensive stills glass is often better than very expensive cine glass.  For example, I once did a projection bench comparison of an older generation Nikon 70-200mm f/2.8 zoom against a $20k Zeiss 80-200 T2.9 CZ.2, and the Nikon was clearly superior, especially in the corners.  I suspect there is a good reason why you *never* see MTF charts of cine glass!

1 hour ago, jcs said:

Is an EF to EF SB possible? Would be cool to have a 'full-frame' C300 II.

I haven't found a way to do it in a compact form factor while maintaining even remotely decent image quality.  There is an infamous Kodak patent that addresses this problem, but the example given in the patent is so incredibly poor that its just not enabling at all.  You could do it with a relay type system, which I would call a Keplerian style, or real image focal reducer.  However, you then wind up with a huge ungainly and under-performing setup just like the old Nikon E3.

25 minutes ago, andy lee said:

Brian , Im using your Metabones XL speedbooster in a similar situation with a Nikon 28-70mm f2.8 (The Bourne Lens) to give me a f2 zoom . I'm DOP on a British Freature film Pandora and we are using this combination as it produces stunning images with you Metabones XL . Im going to send you a PM about the Movie and Metabones .we are committed to shooting the whole moive with Metabones as it makes all the zooms f2 !! we are using the Nikon 80-200mm f2.8 and the 20-35mm f2.8 all with the XL the the exact reasons you have pointed out in you post , size weight £££ and image quality - which is amazing !!

Its incredibly nice to learn about this (!!), and I'd like to know as much as possible about your work.  BTW, a Speed Booster XL will take an f/2.8 zoom down to f/1.8, which is probably around T/2.0 for most zooms.

3 hours ago, Policar said:

The Fuji Premier needs to reach a 52mm flange distance.

It will exciting when this isn't a factor. I still wish there were a C300 speed booster!

What really matters is the BFL, not the flange distance.  In this case, as in most cine zooms, I think the Fuji 14.5-45/2.0 will fit onto a PL-to-EF adapter, so you can think of it as an EF lens.  So, in this sense its equivalent to 24-70mm lenses from Canon, Tamron, or Sigma with an EF mount.

The Fuji Premier 14.5-45mm T2.0 ( http://www.bhphotovideo.com/c/product/840519-REG/Fujinon_HK3_1X14_5_F_HK3_1X14_5F_14_5_45mm_T2_0_ZOOM.html ) is pretty well known in the professional cine world.  But, if you've ever hefted one in person you know its not only priced like a small house (~$100k), its nearly the same size and weight as well!  So, naturally, I'm curious to know how it might perform on the upcoming A6300 in comparison to something much cheaper.  Like the Tamron 24-70mm/2.8 with a Speed Booster, which gives you a 17-50mm/2.0.  Obviously, the latter is practically $free compared to the former, and you do give up the 14.5mm - 17mm range along with perhaps 1/4-1/3 stop difference in aperture due to f/# vs T/#.  But, you gain autofocus, image stabilization, a little extra reach at the long end, and an unbelievably huge reduction in size/weight/cost.  I would not be surprised in image quality is nearly equal.