What is a "Normal" lens on an APS-C Digital SLR Camera? Nikon D300 in Hand, I Find Out.

July 8, 2021

#428

Gentle reader,

For many DECADES a "normal" camera lens, one with a "view" similar to what we see with our eyes was considered around 50mm or two inches for REALLY old cameras.  

However, in the digital camera world, with different sizes of sensors, the question is not so easily answered.

For an example, here is a quote from a more in-depth article on the subject:

"To not get into the slippery territory of dogmatic equivalence, focal lengths in this article refer to 35mm film. So your Olympus 12mm F2 for Micro Four Thirds is a 24mm. The Canon 50mm F1.2L is what it says, a 50mm, but only when mounted on a “full-frame” 35mm sensor. On a Rebel/Kiss the 50mm becomes a longer 80mm." *

I don't recall where I found this chart. But it clearly shows the different sizes of many digital sensors and their size in millimeters. The BLUE frame around each sensor is 35mm full frame for comparison's sake.

Most DSLR cameras (Canon being the exception) use APS-C sized sensors. Which have a "Crop Factor" of 50 percent. 

What that means is a 50mm lens on an APS-C sized (not full frame) DSLR has the "angle of view" of a 75mm lens on a 35mm film or full frame digital SLR camera, not 50mm.

Nikon, and Pentax are, to my knowledge, the only camera makers that maintained their camera mounts from the late 1950's until now.  

So, if I still owned it, I could mount the Nikon 28mm lens (above) from the 1960's on my D300, and in Manual mode make images with it just fine.

This is one of MANY 35mm rangefinder cameras I once had in my collection. NOTE that the lens is 40mm, not the 50mm so often associated as a normal lens for 35mm.

This is a Yashica Lynx which houses the fastest fixed lens (not removable) lens with a maximum aperture of f1.4. "Fast" in this case refers to how much light the lens will let in when the aperture is fully open. Note that it is a 45mm lens.

This image is of the back, or film/sensor, side of camera lenses. The leftmost lens is a 50mm f1.5, the next two are f2.0 and the one on the right is f3.5. As you can see, the higher the number, the smaller the opening or "exit pupil" of the lenses is. Thus, when the aperture is wide open, the one on the left lets in MUCH more light than the one on the right.

All are "M39" or Leica thread/screw mount lenses. All were made in the former Soviet Union. And all are copies of German pre-WWII Zeiss Contax lenses.

Here, the black one, is mounted on my sole remaining 35mm camera. It is a modern version of a Leica 35mm camera. Modern in that it has built-in sensor, adjustable frames in the viewfinder and other things most Leica cameras did not have until many years after they abandoned their M39 lens mount. Note that it is a 50mm or "normal" lens.

The previous photos of lenses and cameras, all 35mm, mounted with "normal" lenses were for illustration purposes as to various camera makers idea of a "normal" lens.

The left lens is a film camera 28mm f2.8 lens, the fastest I could find on my budget. The middle one is a 35mm f1.8 digital lens, the one on the right is also a film lens and is 50mm f1.8.

The two photos above show the three "prime" lenses I bought for my Nikon D300 digital SLR camera. Prime means ONE focal length, and NOT a zoom lens. 

The 35mm lens, being strictly digital, has by default the aperture closed all the way. So, I had to hold it open to show the f1.8 opening which is identical to the 50mm lens.

Here they are with their lens shades mounted. Note the total lack of markings and adjustments on the central (digital only) lens compared to the film lenses on each side.

The following three images were shot in my home office while I stood behind my desk. No flash was used, the reflected light is from the ceiling light fixture.

This was shot with the 28mm lens. 

This was shot with the 35mm lens.

And this was shot with the 50mm lens. Now, as I mentioned, the 50% "crop factor" changes the angle of view of film lenses when mounted on non-full frame Nikon digital SLR cameras.

Thus, the first photo, shot with a wide angle 28mm lens is the angle of view of 42mm on full frame or 35mm film. On the wide end of "normal".

The middle photo shot with the 35mm digital lens equates to 52.5mm. On the long end of "normal".

The bottom photo shot with the 50mm lens is equal to 75mm on 35mm film or full frame digital, which is the beginning of telephoto lens' view. 

Yet, standing here, I "see" this view which was shot with an 18mm lens on a Lumix camera.

The same shot with a 24mm lens on the same camera. Below is the shot from the 28mm lens (42mm in full frame).

A HUGE difference! Here is the Lumix camera I used to make the two photos above this one.

As you can see, it has a Leica Vario-Summilux lens which is equivalent to 24-90mm on full frame or 35mm film. And the lens has the same f1.4 maximum aperture of the huge 45mm lens on the Yashica rangefinder camera. Even at 90mm, it is still a quick f2.3 opening. I LOVE this camera!

Here is the optional 18mm lens mounted on it and also the optional eye-level electronic viewfinder.

Now, of course, the "kit lens" on most consumer Nikon DSLR cameras is the 18-55mm zoom.

This lens equates to 27-82.5mm on a full frame digital or 35mm film SLR. 

The "problem" I have with most zoom lenses, and this is one of them, is their "slow" maximum aperture of f3.5 (remember the right-most lens in the line of M39 lenses? shown below) which is S-L-O-W compared to the f.18 prime lenses. 

And, the aperture gets SMALLER (f5.6) as you zoom out, which means LESS light is getting in requiring a SLOWER shutter speed. 

So, what have we discovered here? That there is no "normal" lens, really, when compared to what our TWO eyes see.

The article I referenced at the beginning of this article is linked below:

*The Focal Length Closest to the Human Eye: If You Had to Take Just One Lens… | THEME

As I mentioned above my distaste for "variable aperture" lenses, such as the Nikon 18-55mm, I was fortunate to obtain a special Lumix camera which has a Leica zoom lens which has a CONSTANT aperture of f2.8 from the wide (25mm) end all the way to 600mm! 

"What? That's impossible," you may be thinking. But it is true. If any company could pull that off, it is Leica. Mine is a Lumix DMC-FZ200. The FZ300 also uses the same lens. 

These are two shots I made with the camera. Above is at 25mm. I am down the street from our house. Note the tiny car dead center above?

This is zoomed all the way out to 600mm! That's my car. The compression of long lenses makes the neighbor's truck appear to be close behind my Volvo wagon, but it isn't.

Getting back to the first image of this article, which shows digital camera sensors compared to full frame. My two Lumix cameras, while both having impressive Leica lenses, have TINY sensors. They have one of the three in the bottom row. 

Compare their size to the APS-C two rows up and the Nikon sensor while having similar pixel count, has LARGER pixels which means less "noise" in the images.

Below is my D300 wearing each of the three lenses shown above and used to shoot the wall opposite me. 

Note how far back in the lens' body is the 50mm front glass element compared to those of the 35mm and 28mm lenses.

My next article I plan to experiment with a vintage front-mount Spiratone 7.5mm fisheye lens on these three lenses.

All three digital cameras I own have their uses. The FZ200 is MUCH lighter than my D300 and there does not exist a 25-600mm lens which I could mount on it. If there was one, it would require a hand-truck to move it around! The LX7 I mostly use for creating images for this blog and selling on eBay. It is compact enough to fit in a cargo pants pocket, when going out. 

For related articles here are some more links:

The Robb Collections: Nikon DSLR Verses Lumix FZ Bridge Camera Does Size Matter?

The Robb Collections: How Large, Heavy and Costly Would a Leica 25-600mm Zoom Lens Be?

The Robb Collections: Panasonic Lumix FZ200 Superzoom Camera Goes Wider and Longer. 19-1020mm!

Thank you SO much for reading my humble blog. I hope that you enjoyed reading it and perhaps learned somethings as well.

Scott

July 8, 2021

#428

WRC Rally Car Homologations. RALLY CARS for THE STREET: Ford Escort RS Cosworth, in 1:24th Scale Diecast Metal.

June 22, 2021

#427 

Gentle reader,

I have been a car guy and racing fan (no open-wheel, or NASCAR) my whole life. I prefer racing which features cars that LOOK like the ones we drive, or would LOVE to drive. The closest thing I watch which is similar to NASCAR is (once called Australian) V8 Supercars. They race mainly in Australia and New Zealand. And prior to Ford and GM closing their factories there after over 100 years, they raced Ford Falcons and Holden Commodores. Both are four-door sedans with V8 engines and rear-wheel-dive. As God intended. UN-like NASCAR, ALL the doors open and close, the lights and (single) windshield wipers work. The cars look almost exactly like the ones the fans drove to the races. They race in the rain, in endurance or sprint races, and not one oval track.

But enough about that, THE most difficult and potentially deadly form of land-motorsports is RALLYING. It has changed MUCH over all the decades since it began. The cars had gotten WAY TOO FAST and the crowds WAY TOO STUPID some years ago, with many of the latter being killed or injured because many stood IN THE ROAD waiting to jump out of the SPEEDING rally cars at the last SECOND. So, they outlawed Group B cars and imposed stricter rules about where fans could watch the racing from.

A screenshot from a WRC rally back in the Escort's heyday. See how close to the road (and the cars race ON real roads, paved or dirt, day and night, in ALL kinds of weather, including in snow) the idiotic fans are!

This shot of the rear of another car, shows the outrageous "bi-wing" rear spoiler which provides excellent downforce at speed.

Those cars were the ones which Ford chose to build to compete in the World Rally Championship, were based upon the humble 1991 Escort two-door hatchback, shown above. This is a photo of a North American model.

THIS is one of the homologation specials, street versions, of the WRC rally cars.

Here is another one, a 1996, from the front 3/4 view. It is in the UK, since it is right-hand-drive. Sadly, North America NEVER received these for sale.

Now, UN-like the REST of the Escorts that Ford built and sold around the world, which were humble, front-wheel-drive cars, with transverse (sideways) mounted single-overhead-cam engines, the Escort RS, had a Cosworth-built, double-overhead-cam, multi-valve engine, which was equipped with an intercooled turbocharger AND all-wheel-drive. 

Here is the humble 1.9 liter SOHC engine which my 1993 Escort station wagon and Nancy's 1994 Escort two-door-hatchback were propelled by. BOTH of our cars had the five-speed MANUAL transmission, as God intended.

And here is the Escort RS Cosworth's longitudinally (front to rear) mounted DOHC engine which propels the NOT-at-all-humble turbocharged engine. Even a non-car person, comparing the two photos can see the difference.

If you are not aware of the word "homologation", it means "to comply with". The "O" in the name of the famous 1960's Ferrari 250 GTO, shown below, stands for "omologato", Italian for homologate.

One of THE most beautiful cars ever created. I think a total of 33 were built. 

America's Pontiac motor division of General Motors, in 1963 also chose to use GTO as the name of their snuck-under-management's-noses, 1964 Pontiac Le Mans GTO "package". 

Enzo Ferrari was not too happy about that, but what could he do?

This composite photo, and all the other ones above, I found on the Internet.

It shows a 1964 Pontiac GTO convertible and 1962 Ferrari 250 GTO. As far as beauty, there is no comparison. BUT, the Pontiac was no slacker performance-wise.

Side-bar: In 1974, when I was a senior in high school and driving home one afternoon from said school, I spotted a '64 GTO convertible with a FOR SALE sign in the window. I pulled over, took a look at it, and knocked on the house's front door. A man answered and I asked if the car was his. It was and he got the keys and we looked it over. I test drove it and WOW! what power! When we got back to his house, I asked, "How much?" "$250, do you think that's too much?" Trying to make a poker face, I replied, "Well it is ten years old, and I paid $300 for my '64 Impala last year, so, it sound's right." Sadly, I was not able to buy it, my dad pointed out: "But you already have a car." "But Dad, this is a GTO!" "You could get in trouble with a car like that." He was right. But, I DID get to drive one and not many car people can say that.

I have been simulation racing for YEARS and one of my favorite cars to race, in any class I can modify it to compete in, is, you guessed it, the Ford Escort RS Cosworth.

Above, you can see two 1:64th scale models of it. The one with #7 on the roof is a Greenlight actual-1:64th-scale replica and above it in the photo is a Hot Wheels version immortalized as "The King" in the 3Dbotmaker's DRC* racing series "driven" by Steven King. Not, THAT Steven King. Diecast Rally Championship (Event 2 Round 1) Hot Wheels Car Racing - YouTube Above that is Hot Wheels Ford RS200 Evolution WRC rally car. Now, THAT car is a handful to drive in racing simulations. *Diecast Rally Championship

Here are photographs of my 2015-era Escort RS Cosworth racer in Forza Motorsports 4, above, and RS200 Evolution below.

One can either learn to decorate cars in the game, or buy (with credits you earned racing) liveries from very talented people who learned how to do it. Some paint schemes have THOUSANDS of layers!

But enough about that, let me show you more photos of my 1:24th scale WRC-looking diecast car.

Made in Italy by Bburago (or is it Burago?), I found that this model was the ONLY one available from a US seller. AND, he only wanted $9.99 for it!

Unlike most diecast cars which have their "livery" or decorations printed on the cars, Bburago chose to print them on clear plastic tape and stick them to the car bodies. The one on the rear of the car (above) makes that obvious.

But the rest of the stickers are not so obvious.

These two shots show that it is a STOCK (street) model and not a rally car model. But, I am OK with that.

Since it (and 99%) of all our not-for-racing diecast car collections merely sit on display in their cabinets, it not being a WRC car does not bother me. 

The OCD parts of my brain wants me to fix the poor job they did with this engine compartment, but I fight those urges.

I have not seen the underside of a real Escort RS, so do not know if this one is accurate or not. But I like the way they have the exhaust and transmission and independent rear suspension differential housing chrome plated to contrast with the black.

I MAY do other articles about homologation street cars in the future. It is fun to research them. SUCH brave and talented drivers (and BRAVE and TRUSTING) co-drivers who sit and read shorthand notes to the driver about what lies ahead.

Thanks for reading my humble blog!

Scott

June 22, 2021