Really large aperture lens dascams.

[nutsey]

Are there any major brand dascams with lens brighter than F1.4?

Several NextBase dash cams use f1.3 lenses. The next question is does anybody know any f1.2 models?

 

[Dashmellow]

I'm surprised to hear the Nextbase offers cameras with such fast lenses. I'm not aware of any other cameras that offer a ƒ/1.2 lens though.

I'm curious to know why you want to buy a camera like this? Why not modify a camera with a lens of your choosing?

Here's a lens I've thought about experimenting with. It's a 4mm ƒ/1.0 available in 3MP or 5MP.

It's probably not the highest quality lens one could buy considering the price and the plastic barrel but I would be interested to see what it could do, especially on a camera with a Starvis sensor. In fact, it is listed as a good match for the IMX335. Maybe when I retire one of my Viofo A119 V3s I will install one of theses lenses on it and see what kind of results I get. Shipping is about as much as the lens though.

https://www.aliexpress.us/item/2255800029208737.html?spm=a2g0o.productlist.main.49.60723149U3dZax&algo_pvid=644c1f24-ff28-4861-9c28-9be830e30b34&algo_exp_id=644c1f24-ff28-4861-9c28-9be830e30b34-24&pdp_npi=4@dis!USD!4.09!4.09!!!4.09!4.09!@2101e9d117061391003334340e410c!12000026452510154!sea!US!0!AB&curPageLogUid=cNSl2tJD0Bhk&utparam-url=scene:search|query_from:

 

[nutsey]

I'm curious to know why you want to buy a camera like this? Why not modify a camera with a lens of your choosing?

I don't want to buy anything. Just doing some research trying to find out the reason why there are no f1.2 dashcams on the mass market yet.

 

[Nigel]

Just doing some research trying to find out the reason why there are no f1.2 dashcams on the mass market yet.

Essentially, it is because an f1.2 lens would require a smaller sensor than most dashcams use, and that would mean poor dynamic range. You can't put a f1.0 lens on a big dashcam sensor because you would have focus problems due to the short depth of field.

It is a result of the laws of physics, and there is no point in arguing with the laws of physics, you will always lose.

This is also the reason that you can't have a DSLR sized sensor in a dashcam, a DSLR size sensor requires autofocus, but a dashcam has to focus on every number plate at the same time, so can not have autofocus. You could use a DSLR with autofocus turned off and the aperture turned right down to f22, but the result would be not significantly better than a normal dashcam, an aperture of f1.0 certainly wouldn't be useable. ("DSLR" is probably an outdated term these days, maybe I should say "Full Frame Mirrorless Camera" or something?)

 

[JardaB]

1 - Isn't better lens luminosity directly related to a wider field of view ??
2 - Then there are worse resolution details

 

[Nigel]

1 - Isn't better lens luminosity directly related to a wider field of view ??

The f1.4 aperture figure takes FoV, sensor size, and everything else into account, so no, any f1.4 lens will put the same intensity of light onto the sensor. The amount of light captured by each pixel does depend on pixel size, but every mm² will get the same amount of light from any f1.4.

2 - Then there are worse resolution details

It is quite difficult to make very wide aperture lenses, they often have poor focus near the edges, good ones tend to be expensive, but it is not impossible to make a high resolution one.

 

[Dashmellow]

I don't want to buy anything. Just doing some research trying to find out the reason why there are no f1.2 dashcams on the mass market yet.

OK, thanks for the explanation.

 

[JardaB]

The f1.4 aperture figure takes FoV, sensor size, and everything else into account, so no, any f1.4 lens will put the same intensity of light onto the sensor. The amount of light captured by each pixel does depend on pixel size, but every mm² will get the same amount of light from any f1.4.

Amount of light, yes, but it is much more convenient to get that amount of light to the sensor from a much larger area of a wide angle lens. That's why telephoto lenses usually have a larger aperture number. And even cheap wide angle lenses have decent apertures.

Similarly, zoom lenses have a different base aperture at either end of the zoom range

 

[Dashmellow]

It is quite difficult to make very wide aperture lenses, they often have poor focus near the edges, good ones tend to be expensive, but it is not impossible to make a high resolution one.

Nikon Full Frame Z Mount 58mm Nikkor S manual focus ƒ/0.95 NOCT has 17 elements (including 4 ED and 3 aspherical), an 11-blade diaphragm and uses ARNEO, Nano Crystal, fluorine and Super Integrating coatings.

 

[JardaB]

It's not dashcam related, as a joke good :-( 10 000 $

 

[Dashmellow]

It's not dashcam related

Well so what? It is interesting and relates to fast lenses and speaks to @Nigel's comment. There is no reason to be so ridged or obsessive about talking just about dash cams in what is posted here. You could learn a thing or two or perhaps just find it entertaining or enlightening.

Here's another post about ultra fast lenses some may find interesting.

In 1975 Stanley Kubrick used a highly specialized custom built ƒ/0.7 Carl Zeiss Planar 50mm lens supplied to him by NASA that was used during the Apollo moon program to shoot images of the dark side of the moon for filming scenes in the film Barry Lyndon using only natural candlelight to convey the feel and atmosphere of the 18th century in an authentic looking painterly image. Amazing use of the optic along with using a custom built shutter mechanism on a specialized Mitchell BNC camera for a unique creative cinematographic purpose, but that was one of Kubrick's specialties often seen throughout his career.

These candlelight only filmed scenes from Barry Lyndon look much softer on YouTube than they did on screen in the movie theater 49 years ago but they are a real testament to what the ƒ/0.7 Carl Zeiss Planar 50mm lens could do. Only 10 copies of the lens were ever made.

(Probably) the most famous lens in the world comes back home

One of the rare ZEISS Planar f/0.7 50mm film lenses that Stanley Kubrick used for his legendary interior shots without artificial light is being presented in a special exhibition at the ZEISS Museum of Optics.

www.zeiss.com

Stanley Kubrick Borrowed Some NASA Tech To Capture Barry Lyndon's Natural Look - SlashFilm

In order to make a drama about the 19th century, the legendary filmmaker needed space-age technology.

www.slashfilm.com

 

[Nigel]

Amount of light, yes, but it is much more convenient to get that amount of light to the sensor from a much larger area of a wide angle lens. That's why telephoto lenses usually have a larger aperture number. And even cheap wide angle lenses have decent apertures.

Similarly, zoom lenses have a different base aperture at either end of the zoom range
View attachment 70468

I'm not sure what you are asking/what your point is?

It is true that the more you magnify the image (The more you spread the image across the sensor), the lower the intensity of light per mm² of sensor.

But an f1.4 always puts the same amount of light on a mm² of sensor, whatever the amount of telephoto and whatever the sensor size.

but it is much more convenient to get that amount of light to the sensor from a much larger area of a wide angle lens.

I think that is incorrect; remember that the light for a single pixel on the sensor does not come from one small area of the lens front element, it comes through every part of the lens front element, so every pixel is affected by the edges of the lens and it is the edges that are the most difficult, especially on a very wide angle lens where the edges are accepting light at a very large angle, whereas on a long telephoto all light comes in almost straight.

 

[Dashmellow]

Virtually every lens with rare exception regardless of focal length or maximum aperture has some level of aberration towards the edges of its coverage and each lens has an optimal aperture setting where it performs at its sharpest. This "sweet spot" is near the center of the lens but the smallest aperture setting is not the best due to a phenomenon called diffraction because when light passes through a lens it bends. When light is forced to pass through a tiny hole in your aperture diaphragm, that unwanted bending becomes more prevalent and results in a less-than-sharp image. The "middle ground" aperture setting, a few stops down from the maximum available aperture generally provides the best performance from each lens because it is using the center of the convex lens which is the flattest area and the position of optimal optical performance, although that setting is slightly different with each lens. Two stops down from maximum is a good rule of thumb, so with a ƒ/1.2 or ƒ/1.4 lens a setting of ƒ/4 or ƒ5.6 would be the point of best optical sharpness.

Of course, none of this applies to dash cam lenses as they have a fixed aperture and this is why very fast Starliight M12 lenses have such shallow depth of field and tend to be soft around the edges of the image. Very high quality lenses like the 58mm ƒ/0.95 Nikkor lens featured above can operate with extreme sharpness across the entire field even with the shallow depth of field. This is why the NASA ƒ/.07 50mm lens could capture such sharp images of the dark side of the moon from a distance.

 

[JardaB]

Nejsem si jistý, na co se ptáte/o co vám jde?

Diskuse se trochu vzdálila problematice palubních kamer.

Chtěl jsem tím říci, že určité světelnosti objektivu (velikost clony) je snazší dosáhnout u širokoúhlých objektivů s krátkou ohniskovou vzdáleností než u objektivů s delší ohniskovou vzdáleností, natož teleobjektivů.

 

[Nigel]

Diskuse se trochu vzdálila problematice palubních kamer.

Chtěl jsem tím říci, že určité světelnosti objektivu (velikost clony) je snazší dosáhnout u širokoúhlých objektivů s krátkou ohniskovou vzdáleností než u objektivů s delší ohniskovou vzdáleností, natož teleobjektivů.

I think it is really only the cost that is an issue, because for the telephoto you need more glass, to collect more light, to cancel out the dimming of the image caused by the magnification. Dashmellow's "Nikon Full Frame Z Mount 58mm Nikkor S ƒ/0.95 NOCT", is not a wide angle lens, it is almost a telephoto, and if you want a really wide aperture long telephoto you can use a telescope/mirror lens. The GMT (Giant Magellan Telescope - largest telescope on Earth) is f/0.71 and seriously expensive!

 

[JardaB]

I think it is really only the cost that is an issue, because for the telephoto you need more glass, to collect more light, to cancel out the dimming of the image caused by the magnification. Dashmellow's "Nikon Full Frame Z Mount 58mm Nikkor S ƒ/0.95 NOCT", is not a wide angle lens, it is almost a telephoto, and if you want a really wide aperture long telephoto you can use a telescope/mirror lens. The GMT (Giant Magellan Telescope - largest telescope on Earth) is f/0.71 and seriously expensive!

Well, it's "just" about the price ... but the price is always the most important !!

Yes, that's what I meant and wrote . Simpler is cheaper ... even for the manufacturer. Let's not talk outside our price range - that's not the point of discussion ($10,000 USD)

 

[Dashmellow]

Well, it's "just" about the price ... but the price is always the most important !!

Yes, that's what I meant and wrote . Simpler is cheaper ... even for the manufacturer. Let's not talk outside our price range - that's not the point of discussion ($10,000 USD)

Price is irrelevant when it comes to posts about the Nikkor S ƒ/0.95 NOCT or the ƒ/0.7 Carl Zeiss Planar built for NASA. I thought perhaps you might find this to be interesting but apparently your mind is narrowly focuseed and unidirectional. Many people on this forum enjoy being intoduced to new things of interest that may be peripheral to a discussion.

M12 dash cam, action cam and CCTV lenses by comparison are fixed focus and fixed aperture low price, mass produced commodity products which don't even usually have actual brand names. They are merely intended for use in a wide range of consumer grade products like dash cams. They tend to be of decent but not particularly outstanding optical quality. Dash cams were invented by using existing, off-the-shelf, low cost CCTV components such as cheap S mount lenses (M12) and the new low cost chip-sets that became available and placing them into a small housing with a battery and a card slot. Thus a new product category was born which also includes actions cams. Now that sensors have improved and much higher resolutions are available, Chinese and Japanese lens manufacturers have had to up their game to match the performance and requirements of the newer technology in products such as drones used in cinematography and broadcast TV as well as dash cams so we all benefit. For example, 10 to 15 years ago there were no aspheric, high resolution lenses seen in dash cams but now they are fairly common.

This is especially true with some of the unique aftermarket Starlight M class lenses that have become available. For the price, the performance is quite good as is the quality and construction of the lenses.The optical designs are often unique as well. One of the Starlight lenses I own is a 6mm ƒ/1.2 that was sold by Treeye on AliExpress that uses a very unique aspherical front element that is concave (bowl shaped) rather than convex (dome shaped) like a typical camera lens but is no longer available from them. The depth of field is shallow but quite viable for dash cam use but these lenses are designed for CCTV cameras so that is why you don't see them on commercial dash cams. As previously mentioned they cab be difficult to focus accurately. I did this lens offered by a different seller I'm not familiar with at a very low price. (see link)

You can still buy a very similar one from both Treeye and Yumiki (second photo) that offers very similar performance. It has a completely flat surface front element.

https://www.aliexpress.us/item/3256806028533317.html?spm=a2g0o.productlist.main.41.1db128b9f2jy5q&algo_pvid=1c6f1afa-6966-481a-bb94-04d942b4d971&algo_exp_id=1c6f1afa-6966-481a-bb94-04d942b4d971-20&pdp_npi=4@dis!USD!7.13!7.13!!!51.00!51.00!@210318cf17065504201953199e3266!12000036314551359!sea!US!0!AB&curPageLogUid=dnWPoVJAqzsI&utparam-url=scene:search|query_from:



https://www.aliexpress.us/item/2251832645656407.html?spm=a2g0o.productlist.main.27.1db128b9f2jy5q&algo_pvid=1c6f1afa-6966-481a-bb94-04d942b4d971&algo_exp_id=1c6f1afa-6966-481a-bb94-04d942b4d971-13&pdp_npi=4@dis!USD!8.99!8.99!!!8.99!8.99!@210318cf17065504201953199e3266!65096660667!sea!US!0!AB&curPageLogUid=uzSXaVyQhbMu&utparam-url=scene:search|query_from:




This isn't the best possible example I have, but it was the most convenient for me to find quickly. It is a screen shot from one of these 6mm ƒ/1.2 lenses. You'll notice that the depth-of-field is not too bad at all.
It was a very overcast day that looks brighter than it was due to the fast lens but motion blur is a bit more pronounced and the focus could use a bit of tweaking which was typical to discover when using this lens.

 

[Nigel]

M class lenses that have become available.

What is an M class lens?

 

[Dashmellow]

What is an M class lens?

Basically any lens that has a screw in mount and is designated in millimeters as in M12. For our purposes this usually refers to fixed aperture, fixed focus screw-in lenses such as M12, M14 and M9 but also certain other screw in lenses that can focus and have aperture settings such as the Leitz Elmar and later lenses that were used on the original Leica rangefinder 35mm cameras (and many others) which were called M39 lenses as well as LTM (Leica Thread Mount) or L Mount (Leica Mount) and probably a few other appellations. In fact, as the first interchangeable lens ever offered for sale on a hand held rangefinder camera the popularity and fame of the 39mm thread Leica lenses over the years has sort of subsumed the designation regardless of which company manufactured lenses with this thread size which included enlarging lenses.

M12 means that the threaded barrel is 12mm in diameter with a 0.5 mm pitch thread. M14 has a 14 mm diameter barrel. M9 (used on the Mobius MIni for instance) has a 9 mm diameter screw-in barrel. I can't recall the thread pitch on the M9 but I believe it is much finer than 0.5 mm. M39 lenses are 39 millimeters in diameter.

There are other threaded lenses still in wide use such as C mount lenses which have a 1 inch (25.4 mm) in diameter barrel with 32 threads per inch (0.794 mm pitch) but they've never really been thought of as M lenses. My guess is that is because C mount lenses were invented by an American company, Bell & Howell, for use on 8mm and 16mm movie cameras (and later/still used for all kinds of purposes) and they were thought of as having 1 inch diameter barrels, rather than metric 25.4 mm ones.

 

[Nigel]

Ahh, a lens mount rather than lens class, using a standard metric thread; thanks for explaining:

ISO metric screw thread - Wikipedia

en.wikipedia.org