Noktor Ultra Fast Cinema Lenses

[Noktor]

Hello RedUsers.

We are beginning development on high quality cinema lenses, and would love to hear some input. Two questions to start the discussion:


The faster a lens, the harder it is to pull accurate focus. Would you rather see something like an f1.1 design for more frequent use, or an f0.95 for extreme situations?
Would a lower priced, fixed iris lens be acceptable, or do you prefer the versatility of iris control?


Thanks,
- Solomon

[MichaelHalsell]

Checking out the gallery on the home page, do you have any video shot with the lens?

[MichaelHalsell]

Sorry, answered my own question.
http://vimeo.com/9820219

[Noktor]

Checking out the gallery on the home page, do you have any video shot with the lens?

The only lens currently available is our 50mm F0.95 for MicroFourThirds (http://www.noktor.com/products.php) cameras. At $799 it is very affordable, but nowhere close to spec for 4K cinema. This thread is for discussing our future cinema lenses.

In any case, here is a video from the MicroFourThirds lens if you are interested:
http://vimeo.com/9820219

[Ross S.]

Are these geared toward the epic sensor covering 5k? On the site I saw the that the one you have already out is for a 4/3. Thats why I ask.

Thanks

[MichaelHalsell]

Is the company developing multiple focal lengths or just the 50mm?

[Noktor]

Are these geared toward the epic sensor covering 5k?
Yes.


Is the company developing multiple focal lengths or just the 50mm?
Yes. Currently 25mm to 85mm, as it is the most practical range for fast lenses. (anything else would be prohibitively expensive or huge)

[MichaelHalsell]

The undeveloped focal lengths, would the pricing be circa the 50mm? What would be a rough timetable for delivery of the entire focal range?

[Tom Lowe]

Go extreme or go home, is my opinion. Once Epic lands with Canon and Nikon mounts ready on day one, a lot of fast stills glass (think EF 50mm 1.2) will become available. I understand the issues of cine-housed lenses vs still, but regardless, you should do something to set yourself aside.

I would say, yes, go extremely fast. But also, go as WIDE as you can. That is where the big hole is in the market. How about 16mm f/1? I don't care if it weighs 100 lbs, I could make use of it.

[Charles Angus]

Hello RedUsers.

We are beginning development on high quality cinema lenses, and would love to hear some input. Two questions to start the discussion:


The faster a lens, the harder it is to pull accurate focus. Would you rather see something like an f1.1 design for more frequent use, or an f0.95 for extreme situations?
Would a lower priced, fixed iris lens be acceptable, or do you prefer the versatility of iris control?


Thanks,
- Solomon

1. I would vote for faster. So long as the mechanics are smooth, pulling focus at f/0.95 won't be much harder than f/1.2 (like a Master Prime or Super Speed) - my DoF calculator is showing that at 50mm and 6 feet (what I would call a medium-close-up), f/1.2 gives you 3.1" of DOF while f/0.95 gives you 2.4". Not a huge practical difference - you still have to bloody nail it.

Faster also differentiates your product more from the competing products. The other fast cinema lenses are f/1.2 (Master Primes, Super Speeds, the new Leicas, I think - although they may be f/1.3, as they are T/1.4 instead of T/1.3). F/1.1 is not really enough difference to make your lenses stand out from the crowd.

2. Fixed iris is completely unacceptable. Remember that for cinema applications, we can only control exposure by ISO, aperture, and neutral density. ISO you generally want to leave constant throughout a scene (and not be futzing with it shot to shot), and neutral density filters are not normally scene in less than 1-stop varieties. Also, neither can be controlled during the shot. Smooth, click-less aperture control is essential.

I would love to see some reasonably-priced faster options out there. Or even just faster options...

[Kyle Presley]

Iris control please.

[MichaelHalsell]

I agree with Mr. Angus.

[Charles Angus]

Cover APS-C, not just Super-35, and you'll have REAL winners if you can make them in EF and Nikon mount.

[Kim Frank]

fast, fluent iris control, different mounts, same form factor or at least front diameter and please don't make them big and heavy - but thats gonna be an expensive set

[Dustin Cross]

Must have iris control.

Fast is great, but it has to look good wide open.

You really need to add an 18mm.

Cover full frame 35 would be great.

PL, Nikon, EF mount.

Internal focus. It becomes a problem with cine accessories when the lens changes size.



Dusty

[sander kamp]

First of all I think it is great to have a new player on the cinema lens market!

To answer your questions:

1. Extreme is probably better. And personally I think it would be better to go for the 'interesting' look rather than the perfect lens. All new lenses tend to go for the clean, sharp and evenly illuminated look with big, heavy barrels. If you prefer a softer look with some vignetting you have to go after vintage lenses which become more scarce every day and mostly have bad mechanics.

2. Yes, iris is essential. And focus and iris gears please, a long throw and big numbers.

[James McLellan]

Interesting that no-one would consider a fixed iris lens. In this new age of non-fixed ISO's I should think if a fixed iris brings the price down to $1000 for f1.1 or something ridiculous that you could learn to shoot using ND and ISO for exposure. That is, IF the fixed aperture in question is sharp enough.

I would think if a fixed iris kept the weight and price down it might be a new niche for lenses.

At that price you could have the fixed iris lenses in your toolbox for all your interior/night scenes and have a slower zoom for daylight stuff.

Of course focus gears are essential and I must agree with earlier posts that something wider than 25 mm could be necessary.

Just my thoughts.

[Joel Kaye]

I'd rather see a 18mm F/1.4 than an uberfast 50. I already have a 50 F/1.2 on my RED and rarely shoot it wide open. The camera bodies are so light sensitive and getting moreso that I have a hard time believing superfast lenses matter that much. Certainly the wider the better - focus on those. And yeah, you should have aperture control.

@ james - lowering ISO on a RED doesn't help. ISO is simply metadata and has no actual effect on reducing the amount of light hitting the sensor.

[Fredrik Callinggard]

Interesting that no-one would consider a fixed iris lens. In this new age of non-fixed ISO's I should think if a fixed iris brings the price down to $1000 for f1.1 or something ridiculous that you could learn to shoot using ND and ISO for exposure. That is, IF the fixed aperture in question is sharp enough.

I would think if a fixed iris kept the weight and price down it might be a new niche for lenses.

At that price you could have the fixed iris lenses in your toolbox for all your interior/night scenes and have a slower zoom for daylight stuff.

Of course focus gears are essential and I must agree with earlier posts that something wider than 25 mm could be necessary.

Just my thoughts.

Interesting that you would think so, but in a shooting environment it would render the lens only useful when shooting low light situations. I'm having problems already with RED being 320 ASA shooting exterior on a sunny day with ND 1.8 + 0.9 to come down to T4 - what would it look like if I needed to come down 4 more stops :laugh:.... not to talk about the IR level on so many ND in front of the lens

Edit: I was shooting in extreme sunny conditions when I had to come down that much

[Sanjin Jukic]

By the laws of physics with any lens at the speed below f/1.4 (T1.3) you can't avoid aberrations like a slight coma:

http://www.imx.nl/photo/leica/lenses/page150/files/l1005222.jpg
Leica Noctilux 50mm f/0.95 ASPH: There is slight coma at the outer zones of the image field>>> see at the left side of the picture.

"NX 0.95 wide open

The NX 0.95 is the most recent addition to the Leica CRF scuderia employing aspherics and floating elements.
When comparing the MTF graphs you can appreciate the quantum leap forward at the widest apertures.
At 1:0.95 astigmatism is well controlled as is curvature of field. Overall contrast is low to medium,
but the focus shift when stopping down is very well controlled. This implies that spherical aberration has been
reduced to low amounts, but one cannot expect a lens with such a wide lens diameter to have crisp definition
of fine details. And where fine detail is soft, the delineations of major subject outlines will be soft too.
To get sharp edges at subject outlines, we need lots of high frequencies to create this sharp boundary.
The performance of the old Zunow lens at 1:1.1 can only be described as a last resort when you desperately need that picture.
The NX at 1:0.95 performs so well that you hardly will guess that the picture was made with a superfast lens.
At this point in the report, we need to take great care in examining the performance profile of the NX.
When testing a lens, and even when just examining the results of the lens, it is quite easy to select and present the good,
the bad and the ugly aspects of a lens. The occurrence of vignetting is such a case.
The technical data sheet reports a vignetting value of 20% at the edges or more than two and a half stops.
There are picture situations where you will very clearly see this strong darkening in the edges.
But there are also many instances where the vignetting is negligible. We should also be aware of the optical specifications.
A superfast lens with a wider angle of view will exhibit vignetting, caused by a number of factors: size of mechanical mount,
cosine 4 law, and image distortion. There is a trade off between distortion and vignetting and the Leica design favors a low level of distortion,
in my view a fine choice. This discussion is not meant to diminish the effect of vignetting in the Nx 0.95 but to indicate
that we should differentiate between an optical error and an optical given. Focus shift on the other hand is an error that
can be corrected without severely effecting other aberrations.

Erwin Puts - Tao of Leica>>> (http://www.imx.nl/photo/leica/lenses/page150/page150.html)

[Paul Leeming]

Fast, wide (10-18mm) and in PL, EF and Nikon mounts, and you'll have an instant winner that will sell boatloads.

Got to have iris control though, even if it's only to T8 or similar if that makes it easier/cheaper to manufacture.

Cheers!

Paul

[Kim Frank]

Interesting that no-one would consider a fixed iris lens. In this new age of non-fixed ISO's I should think if a fixed iris brings the price down to $1000 for f1.1 or something ridiculous that you could learn to shoot using ND and ISO for exposure. That is, IF the fixed aperture in question is sharp enough.

I would think if a fixed iris kept the weight and price down it might be a new niche for lenses.

At that price you could have the fixed iris lenses in your toolbox for all your interior/night scenes and have a slower zoom for daylight stuff.

Of course focus gears are essential and I must agree with earlier posts that something wider than 25 mm could be necessary.

Just my thoughts.

ISO is just metadata. With Heavy NDs how would you Control IR pollution. And also how do you Control DOF wich still is an artistic Choice. There are hardly no lenses that look good wide open. You have to bring them down one or two stops, but the wider you start the wider you end.

And threre is I think a reason for modern lenses trying to avoid vingetting, it's nicer to add it in the post, than trying to get rid of it

[Ryan E. Walters]

1. Need Iris control.
2. Cover Full frame 35 (Or at least the Super 35 of the Epic.)
3. Light weight.
4. Consistent speed across the set.
5. Lens Gears for focus and iris. (Focus at a minimum)
6. Focus in the cine direction.
7. Same diameter fronts.

[James McLellan]

It's been well established that the mysterium sensor ISO is metadata, however it was more widely accepted that the native ISO fell between 250 and 320.

The mysterium X sensor native ISO however has been more difficult to pinpoint based on what I have read. Sooo... although it is still metadata, as Jim himself said, one could consider a range of ISO's as acceptable.

I can only imagine that as manufacturers it must get tiring for them to ask what do you want and have everyone give them a list of master prime features then expect a price of $500.

I have never shot on a fixed iris lens. At one point I had looked at duct taping some old projector lenses (fixed iris) to the red to see what kind of weird look I could get but never got around to it.

Clearly fixed iris would be less than ideal but I thought, is there a way to make that work? Anyways, all just ideas floating around.

[sander kamp]

And threre is I think a reason for modern lenses trying to avoid vingetting, it's nicer to add it in the post, than trying to get rid of it

No, vignetting never looks as good in post, it always looks fake to me. When it happens in the camera you get different exposure in the corners of the image, which is not the same as just making it darker.

[Joel Kaye]

It's been well established that the mysterium sensor ISO is metadata, however it was more widely accepted that the native ISO fell between 250 and 320.

The difference between ISO 250 and 320 has very little effect on exposure. Going up in ISO is irrelevant in the current discussion. It's not like we can rate RED at 25 and make a fast lens usable.

I suppose it's possible these lens may be of use ONLY wide open and you buy them as a specialty lens.

OK - so it's a specialty lens meant for low light interiors and night exteriors. I guess that might make sense. My experience with exposure and RED indicates I almost always have at least F/1.4 of light. So if I had to pick I might be inclined to buy a 18mm F/1.2 or F/1.4 over a faster version.

The real market opportunity is F/1.something at 18mm and wider in my mind. Perhaps a superfast 50mm makes a bit of sense for rare situations. I didn't fall in love with the look when Kubrick did it though... so it's not really something I'm personally looking for.

As to use potentially hurting the feelings of people looking for free advice - it may just be we're saving these guys a lot of time, money and pain long term.

[Michael Grugal]

They need to cover FF 35 Still Photo sensors

[Shane Betts]

Are you planning any autofocus? With Epic Canon and Nikon mounts available when the camera ships, with touch screen focussing and the Redmote Pro, I'd think a Canon or Nikon mount with focus motor would be very handy.

Yes, iris control and yes, wider, wider, wider. Good luck with it!

[Dustin Cross]

Just a thought, but there is a ton of competition in the cine prime lens market right now.

Red - 18mm - 100mm T1.9
UniQoptics - 18mm - 100mm T1.9
Luma Tech - 18mm -85mm T1.3
Zeiss CP2 - 18mm - 85mm T1.5 - T3.6
Schneider - 18mm - 95mm T1.9 - T2.2

Unless you are planning to sell you lenses for around $1000 per lens you will have a lot of competition from those guys.

And those are just the low cost guys. You still have the big guys Cooke, Arri, Leica.

Plus you can still buy used sets of Zeiss Super speeds and Standard Speeds and Canon K35 Super speed sets

Even at $1000 per lens you will need to meet all cine lens standards. i.e. adjustable iris, preferably geared, geared focus, PL mount, long focus travel, accurate marks for distance, standard front size. Plus you will need an 18mm to compete. 25mm is not quite wide enough.

It would also be nice to have internal focus so the lens doesn't change size as we roll through the focus. Small and light weight are nice, but not required. great contrast and color. cover ff35.

A nice really affordable set of fast primes would be great. If you do a complete set of lenses all T1, that would be amazing, but if there is so much CA at T1 that it is not usable, and we have to stop down to T2 to use the lens....

There doesn't seem to be much competition in affordable zooms right now. That would be a place you could sell some lenses.

Right now we have:

Red - 17-50mm, 18-50mm, 18-85mm, 50-150mm
Duclos - 11-16mm

That is it for low cost cine zoom lenses. If you could come up with an 18-200mm like the still guys have and make it faster than the f5.6 it would sell.

Or a low cost 25-250 would be awesome. The good ones are more than a car, but you can get the Russian lomos for dirt cheap when they come up for sale.

Just my thoughts.


Dusty

[OptiTek]

I have a 20mm T1.9 coming for about $1500-maybe less. Lightweight and robust.
Sorry about the minor hijack but did not want to make a big deal(new thread ) about it and wanted to help out keep this one afloat.:angelsad2:

[Ryan E. Walters]

I wouldn't think that the price would have to come in around $1000- that seems rather low and I would worry about quality at that price. I would think that if the price came in around $2000 - $3000 per lens that would be a killer deal.

[Dustin Cross]

I think all the other low cost prime sets cost just over $3000 per lens.

$1000 per lens is the extreme low I think. The Zeiss ZF lenses are under that and everyone loves them.

I think under $2000 per lens would sell a lot of lenses if they meet basic cine standards and have good glass. Once you get to $3000 per lens, you have to be better than the competition.

[Tom.Wong]

another question is, are you guys going to shoot for FF cine lenses, or S35? the competing still glass, already have a one up in FF and speed, and from what I've learned, FF glass has a lot of optical limitations when it comes to speed. Those will be other questions that will help you push these lenses...

[Sanjin Jukic]

Hey guy,

if you really want to learn basic(s) and more about FF35mm lens design

please visit from time to time this LINK>>>> (http://www.imx.nl/photo/)

and then we could talk later about what we would need and what is possible to achieve @ FF35mm.

All others sort of discussion and suggestions HERE are all in-appropriate.

[Dan Kanes]

Personally I'm happy to accept a set with good mechanics, and T1.5-T2.0 priced at around $1500/lens or less. As far as lens character:

Chromatic Aberration AKA Fringing is a no-no.
Coma and Flare characteristics wide open are a good thing in my book.
Make them with a stainless PL mount.
Dual Distance and T Stop scales.
Non-Clicked Iris is a Plus. However it MUST have iris control.

Make them shimmable so that they can be adjusted correctly for flange.

I remember hearing that Samyang (korean optics manufacturer) was looking into making an aspherical 35mm f1.2... Perhaps you should partner with them to get some Cine Lenses made in PL mount? Some people seem to like their 85mm f1.4...

Personally I don't care at all for an f0.95 lens - so sick of the "shallow depth of field look" I can shoot at a T4 on Red and still get shallow enough depth of field on a 50mm, just like on film.

Honestly, if you did like the Cineovision guys used to do and just rebuild Contax Zeiss or Nikkors into cine lenses you would have a winner if you could do it cheap enough to still make yourself a profit.

[David Mullen ASC]

Doesn't it depend on how sharp the lens is wide-open? After all, the f/1.1-ish 50mm has been available for cinema use for years but is hardly used because it's rather soft at that f-stop.

[Matt W.]

Doesn't it depend on how sharp the lens is wide-open? After all, the f/1.1-ish 50mm has been available for cinema use for years but is hardly used because it's rather soft at that f-stop.

I have to agree pretty completely with this; the ultra-fast lens phase passed in the 1970s--when extremely fast lenses were used for natural light photography on films like Barry Lyndon and Days of Heaven. Film speed and resolution have both increased since then and the diffused look is less fashionable. So lens resolution has since trumped speed. (It's worth noting that fast glass is nothing new: some of the earliest Russian silent films were shot on near-f1 lenses!)

Besides, pulling focus at t1.3-t2 is already nearly impossible and a smaller circle of confusion (higher res) just makes this worse. And it appears the newest batch of digital cinema cameras are clean to nearly 2000ISO--four and a third stops faster than 100ISO, which is what Kubrick and Malick were working with (though they would often push a stop or two).

There may be a market for ultra-fast lenses among enthusiasts, but the professional glass market seems pretty saturated with expensive fast lenses. And, from still images I've seen, the only ultra-fast (non-cinema) glass I'd consider using wide open for anything other than a "dream effect" would be like the nokton or noctilux or some of canon's l lenses.

[Pawel Achtel]

By the laws of physics with any lens at the speed below f/1.4 (T1.3) you can't avoid aberrations like a slight coma:


Some lenses seem to defy physics, Sanjin. Attached frame shot at f/1.2 at extreme 14mm focal length. The smudging is mostly due to earth rotation and vibrations as the shutter was about 20 seconds.

Here is my 2 aussie peso:

1. MTF > 40% at 50 lp/mm
2. Full 35mm frame coverage for extreme light gathering capability on a sensor that has about 3 times the area of S35mm.
3. f/.9 or don't bother. Preferably f/.8. There is a good selection of excellent f/1.2 (T1.3) lenses already (Leica, Arri,...).
4. 24mm will do on a FF35, but 20mm would be preferable. Don't bother with focal lengths beyond 50mm because it is next to impossible to focus the damn thing when DOF is 1mm.
5. Drop the iris if it means significant reduction in cost. This is a specialty lens, not a do-it-all lens. But ensure nice round bookeh.
6. Well controlled flare from point sources.

[Sanjin Jukic]

Some lenses seem to defy physics, Sanjin. Attached frame shot at f/1.2 at extreme 14mm focal length. The smudging is mostly due to earth rotation and vibrations as the shutter was about 20 seconds.

Here is my 2 aussie peso:

1. MTF > 40% at 50 lp/mm
2. Full 35mm frame coverage for extreme light gathering capability on a sensor that has about 3 times the area of S35mm.
3. f/.9 or don't bother. Preferably f/.8. There is a good selection of excellent f/1.2 (T1.3) lenses already (Leica, Arri,...).
4. 24mm will do on a FF35, but 20mm would be preferable. Don't bother with focal lengths beyond 50mm because it is next to impossible to focus the damn thing when DOF is 1mm.
5. Drop the iris if it means significant reduction in cost. This is a specialty lens, not a do-it-all lens. But ensure nice round bookeh.
6. Well controlled flare from point sources.

Pawel,

I was talking about a blue light as a sort of concentric zone of a lens forms a ring-shaped image called comatic circle or coma:

Coma

In spherical lenses, different parts of the lens surface exhibit different degrees of magnification.
This gives rise to an aberration known as coma. Each concentric zone of a lens forms a ring-shaped image called a comatic circle.
This causes blurring in the image plane (surface) of off-axis object points. An off-axis object point is not a sharp image point,
but it appears as a characteristic comet-like flare. Even if spherical aberration is corrected and the lens brings all rays to a sharp focus on axis,
a lens may still exhibit coma off axis. As with spherical aberration, correction can be achieved by using multiple surfaces.
Alternatively, a sharper image may be produced by judiciously placing an aperture, or stop, in an optical system to eliminate the more marginal rays."

http://www.cartage.org.lb/en/themes/sciences/physics/optics/Optical/Lens/lenspr12.gif
Graphics that describes COMA.

LINK>>> (http://www.cartage.org.lb/en/themes/sciences/physics/optics/Optical/Lens/Lens.htm)

So when I've "blowed up" your example the coma or blue light as a lateral chromatic aberration was there.

http://homepage.mac.com/sanjinjukic/RED/coma_pawel.jpg
Blow up detail from the Pawel's example.

That's all about the (lens) physics.


Doesn't it depend on how sharp the lens is wide-open? After all, the f/1.1-ish 50mm has been available for cinema use for years but is hardly used because it's rather soft at that f-stop.

Panavision have listed the lens with T1.1 speed in their rental catalog.

But today's fast lenses using aspherical glass elements have got pretty sharp wide open.

My examples:

http://homepage.mac.com/sanjinjukic/RED/noctilux-095-01.jpg
Shot handheld on R1-M with Leica Noctilux-M 50mm f/095 ASPH Demo lens @ wide open f/0.95, R1 firmware build 15.
(On the picture is Franz Gibiser, a friend of mine, owner of Camera 31 (http://www.camera31.com/), a Viennese second-hand camera/lens shop).

Download 4K JPG>>> (http://homepage.mac.com/sanjinjukic/RED/noctilux-095-01-4k.jpg)

http://homepage.mac.com/sanjinjukic/RED/noctilux-095-02.jpg
Shot handheld on R1-M with Leica Noctilux-M 50mm f/095 ASPH Demo lens @ wide open f/0.95, R1 firmware build 15.
(On the picture is Franz Gibiser, a friend of mine, owner of Camera 31 (http://www.camera31.com/), a Viennese second-hand camera/lens shop).

Download 4K JPG>>> (http://homepage.mac.com/sanjinjukic/RED/noctilux-095-02-4k.jpg)

http://homepage.mac.com/sanjinjukic/RED/nokton-f1-1.jpg
Shot handheld on R1-M with Voigtleander Nokton-M 50mm f/1.1 ASPH @ wide open f/1.1, R1 firmware build 20.

Download 4.5K JPG (http://homepage.mac.com/sanjinjukic/RED/nokton-f1-1-4-5k.jpg)

[XiaoSu Han]

Low cost, not too heavy and big, not too fast (1.8 is enough with the new sensors also regarding focus pulling), proper manual mechanics, get a different coating than anybody else (signature) and you've got a product thats a bit different than the competition and you'll sell more. cater the niche market. can't join the big boys.

to say it in one word, cooke panchros 2010 (but not as costly as the cooke ones and maybe 2.0 instead of 2.8)

the "cheaper" lenses also dont have more intersting focal lenghts,

what about a set of:

15, 21, 27, 33, 38, 45, 66, 72, 88? I'd buy that :)

[MichaelHalsell]

Low cost, not too heavy and big, not too fast (1.8 is enough with the new sensors also regarding focus pulling), proper manual mechanics, get a different coating than anybody else (signature) and you've got a product thats a bit different than the competition and you'll sell more. cater the niche market. can't join the big boys.

to say it in one word, cooke panchros 2010 (but not as costly as the cooke ones and maybe 2.0 instead of 2.8)

the "cheaper" lenses also dont have more intersting focal lenghts,

what about a set of:

15, 21, 27, 33, 38, 45, 66, 72, 88? I'd buy that :)


Practical observations.

[Charles Angus]

You're clearly interested in "hyper-primes", as you call them - don't let the doubters talk you out of making a unique and interesting product.

[Joe Carney]

You're clearly interested in "hyper-primes", as you call them - don't let the doubters talk you out of making a unique and interesting product.

I agree, if you think there is a market, go for it.

btw, since we are all dreaming.
A well designed/made 16-128mm (8x) T2 zoom for around 20K USD would be a big hit,
if it could match the quality of most primes.

[D_Bigelow]

I've used some Noctor stuff on my Leicas and it's wonderful! I'm right now shopping for some decent priced high quality pl mount primes and am having a very hard time finding much. It's either expensive, or crap......very little in the middle. I'd love a new set of Cookes, but it's out of my league.....on the other end of the spectrum is old worn out you-fix it glass or "f/need surface of the sun" junk to get a decent image. I'd buy Noctons in a minute, and agree iris control is essential.