Does medium format take in more light?

[Roger Thoms]

You just have to be sure to screw up in ways that cancel each other out. For instance, if you are going to forget to close the lens, it's important to also forget to take out the dark slide.

And be sure to forget to process the film. Of course this is all mute if you forgot to load the film holder.

Roger

 

[Bill Burk]

Hi Roger, hope you’re doing well...

You of all people could probably explain it well because you shoot different sizes and print them to show together. I was quite impressed with your show at the Sanchez where your 35mm and 4x5 were seamless side by side.

I would say that you have these rules of thumb to consider. Like 1/ focal length as the slowest handheld shutter speed. The “normal” lens goes from 50mm (35) to 80mm (120) to 135mm (4x5), and in a 50mm lens you can get an f/1.4 easily but with 80mm you’re lucky to have f/2.8 and with a 135 you might get f/4.7

So as you go up in size it’s getting harder and harder to handhold with the same film as you lose light (in bright daylight there’s no problem).

Fortunately you can switch from 100 speed film in the smaller formats up to 400 speed in larger format, and the grain isn’t as apparent... in prints the same size from the different size negatives.

 

[RalphLambrecht]

I know for camera sensors, for example a micro 4/3 sensor is less sensitive to light than a full frame (35mm equivalent) sensor. At the same aperture and shutter speed, a full frame sensor is capable of much better low light performance because it takes in more light.

How about medium format, is it more light sensitive due to having a bigger "sensor" or "contact area"? For example, a 75mm 4.5 medium format lens, does it take in the same light at 4.5 as a 75mm 4.5 35mm film camera lens? Or more light?

Is there some sort of "equivalency" in the numbering or is there any difference in metering here to be aware of...

f/4.5 is f/4.5.

 

[RauschenOderKorn]

I know for camera sensors, for example a micro 4/3 sensor is less sensitive to light than a full frame (35mm equivalent) sensor. At the same aperture and shutter speed, a full frame sensor is capable of much better low light performance because it takes in more light.

How about medium format, is it more light sensitive due to having a bigger "sensor" or "contact area"? For example, a 75mm 4.5 medium format lens, does it take in the same light at 4.5 as a 75mm 4.5 35mm film camera lens? Or more light?

Is there some sort of "equivalency" in the numbering or is there any difference in metering here to be aware of...

Actually a good question a difficult to answer. The maths get complicated quickly, so let´s try without.

To understand your question, start simple. Forget about equivalency which is used in digital for focal length and aperture and also forget about zoom lenses. Think of an old wooden camera with a fixed focal length. Let´s assume the lens has a focal length of 80mm and is focused at infinity - i.e. the lens is 80mm from the film plane - and this camera has a 4x5 back, and an adapter for MF and 35mm (and the lens covers that 4x5 area). So you can put in a 4x5 sheet of film, or by means of the adapter, you can use an MF film or even 35mm. Aperture does not change, focus does not need adjustment, only the film size is changed. The amount of light projected on the film per square inch remains the same. What changes is the portion of the light projected you are actually catching with the smaller or bigger film. So in the old days, a lens was not made for a film format, but could be used on different formats. Many MF folder cameras for 6x9 and 6x6 actually have lenses, which were also used in LF cameras.

If you have a lens produced for a certain format (e.g. "digital" lenses for small sensors), the aperture and focal length are stated at an equivalency (and sometimes also the real data). So the apertures given for these lenses are equivalencies and standardised to the same amount of light per image area.

But the basic rule is: at the same real aperture, the same amount of light is projected to the same image area.

 

[Ariston]

You guys are all forgetting about the Burkheimer Effect.

 

[Dan Fromm]

A standard lens in 6x9 is ~100mm, while it's equivalent view in FF is 50mm.

43mm. Do the arithmetic, and remember that nominal 6x9 (6x9 is a poor metric approximation to the true size, 2.25" x 3.25") is 56 mm high by, depending on the roll holder, 78 to 84 mm.

 

[Dan Fromm]

You guys are all forgetting about the Burkheimer Effect.

Berkheimer effect? Not clear that it is real and in any case I don't see it here. Instead I see rampant Dunning-Kruger.

 

[Mainecoonmaniac]

Berkheimer effect? Not clear that it is real and in any case I don't see it here. Instead I see rampant Dunning-Kruger.

. Don't forget Freddy Kruger.

 

[Alan Edward Klein]

Ok, so now I got myself confused about how much light. I want to follow up on the OP's question.

Let's say I'm painting a wall with a roller. I spread 1 pint of paint over a 2 foot by 2 foot section (4 square feet) to a paint thickness of 1 millimeter. Then I paint a wall section that is 4 feet by 4 feet (16 square feet) also to a thickness of 1 millimeter. I would use 4 pints of paint in the second case. So the actual paint thickness is the same regardless of the size. Of course, the total amount of paint is 4 times the first.

Similarly, isnl;t that the way light works in a camera? Let's say I shoot 35mm and compare to medium format 6cm x 6cm (let's assume 4 times area bigger), the total amount of light photons on the film or digital sensor will be 4 times greater with the MF even though the amount of light photons on any one spot is the same regardless of the size of film or sensor.

So how does my example work with f stops and different lenses used to get the same aspect ratio of the scene?

 

[MattKing]

So how does my example work with f stops and different lenses used to get the same aspect ratio of the scene?

It is slightly difficult to give you a good example of how to think of this because the different formats we work with, and the lenses we tend to use with those formats, don't easily scale up to make comparisons between them.
But I'll do the best I can.
Assume a head and shoulders portrait and a similar working distance. You choose the lenses for each format to fill the negative the same way.
In my earlier example of 135 film (using 32mm x 24mm), which has a diagonal of 40mm. So a 40mm lens would be a perfect "standard" lens for that format.
Now think of a special, larger than real life version of 120 film, that allows you to have an image area of 64mm x 48mm, which has a diagonal of 80mm. So a 80mm lens would be a perfect "standard" lens for that format.
As you can see, the larger format is four times the area of the smaller format.
An f/4 aperture for the 40mm lens will have a diameter of 10mm. The amount of light transmitted through that aperture is a function of the square of that diameter - 100mm squared.
An f/4 aperture for the 80mm lens will have a diameter of 20mm. The amount of light transmitted through that aperture is a function of the square of that diameter - 400mm squared.
So when comparing the lenses, the aperture on the longer lens transmits four times the light as compared to the shorter lens.
But the light transmitted by the longer lens is spread over film that has four times the area, so the light intensity at the film is the same between the two cameras.
And the exposure is relative to that light intensity at the film.
QED

 

[brainmonster]

Could it be that crop sensor manufacturers just "advertise" their lenses at F1.8, F2.8 or whatever equivalencies just to marketing purposes? And that this doesn't apply to Medium format. I don't see any other reason for it to be that way. So in reality an F1.8 ASP-C lens is an F2.7 lens and they are just marketing "equivalencies". I don't even know how they are applying F-stop in this case to the crop sensor.

Who's Burkheimer? Was that a joke?

 

[Alan Edward Klein]

Thanks Matt. I understand that explanation very well.

 

[Dali]

Aperture (f/2.0, f/4.5, etc...) has nothing to do with sensor size or film size. This is a lens feature, not a camera feature.

 

[Mainecoonmaniac]

So how many handheld meters have a film format setting?

 

[Alan Edward Klein]

So how many handheld meters have a film format setting?

I use a hand held meter when I'm shooting medium format film. My camera doesn;t have a meter built in. The hand held meter doesn;t care what camera or lens you use. It's only telling you what setting you have to use to get the correct exposure. Whatever the meter says, applies to every camera and lens whether for film or digital.

 

[Pieter12]

I think it has something to do with the number of photons per crystal of silver halide, divided by the ignorance of the user.

 

[brainmonster]

I think it has something to do with the number of photons per crystal of silver halide, divided by the ignorance of the user.

Funny stuff. Anyway, I saw somewhere in a lecture that full frame digital cameras have bigger pixels. If you imagine a pixel as a bucket, it takes in more light because there is more available space for it to absorb more light particles, thus resulting in higher dynamic range and higher light sensitivity.

By the way, full frame lenses spread light over a larger area than a crop sensor lens, which spreads it only over the smaller area of the crop sensor. Thus crop sensor lenses can only be used on crop sensor cameras in "crop mode" without vignetting.

Apparently medium format cameras cannot use 35mm lenses for the same reason, as the image circle is too small.

How this all applies to medium format, I have no idea.

 

[Mainecoonmaniac]

I use a hand held meter when I'm shooting medium format film. My camera doesn;t have a meter built in. The hand held meter doesn;t care what camera or lens you use. It's only telling you what setting you have to use to get the correct exposure. Whatever the meter says, applies to every camera and lens whether for film or digital.

I do the same thing. My only MF camera is my Zeiss Super Ikonta IV. It has a built, uncoupled selenium meter. Still works. I treasure it because my wife gave it to me. . My handheld meter doesn't care either.

I understand why someone would ask this question of relationships between formats and if they use more light. But I find the minutiae of this post not useful. For some, this may cause more confusion.

 

[jimgalli]

Wow. You guys are mean. Aperture is a mathematical size equivalent of focal length. So a 4" lens at an f4 aperture, the aperture number is 1/focal length. f4 1/4 of 4" is a 1" aperture opening. Now if that 4" lens is looking at a 35mm, a medium format, even a large format image plane, don't confuse coverage with more light. It can never let in more light than can get through the hole. But if it's covering 4X5 instead of a postage stamp, the same amount of light covers more area. There are 4" lenses that can cover the 5X7 format. The angle gets huge, like 100+ degrees to do that. So on 35mm 4" is a tele-photo effect. On medium format 6X9 it's "normal". On 4X5 it's "wide field" and on 5X7 it's extra wide angle. A 4" Goerz Dagor can do all of those jobs and it would surprise you how sharp it would be even on enlarged 35mm.

I'd take issue with the lads that say LF is expensive. There are old school 4X5's going begging on Ebay these days for very little money. The whole idea is to have some fun. Nobody gets rich doing this stuff.

 

[Sirius Glass]

Wow. You guys are mean.

Please leave the being mean hate crimes of beating up the unpopular fat kid after school back in your junior high school days.

 

[jimgalli]

Please leave the being mean hate crimes of beating up the unpopular fat kid after school back in your junior high school days.

Point proven.

 

[MattKing]

Could it be that crop sensor manufacturers just "advertise" their lenses at F1.8, F2.8 or whatever equivalencies just to marketing purposes? And that this doesn't apply to Medium format. I don't see any other reason for it to be that way. So in reality an F1.8 ASP-C lens is an F2.7 lens and they are just marketing "equivalencies". I don't even know how they are applying F-stop in this case to the crop sensor.

Who's Burkheimer? Was that a joke?

Nope.
The only "fudging" that the crop sensor digital people do is to refer to a "35mm equivalent", which is actually fairly handy.
An f/stop is the ratio between how long the lens is, and how big the aperture is.
A 12mm aperture on a 48mm lens gives you f/4 - you might find a lens like that on a full frame camera.
A 6mm aperture on a 24mm lens gives you f/4 - you might find a lens like that on a micro 4/3 camera.
And if you compensate for the difference in aspect ratio, you will get the exact same field of view with the two lenses and "sensors", and once the light travels through the lens and spreads out to cover the two "sensors", it will be at the same intensity, leading to the same exposure.

 

[MattKing]

Funny stuff. Anyway, I saw somewhere in a lecture that full frame digital cameras have bigger pixels. If you imagine a pixel as a bucket, it takes in more light because there is more available space for it to absorb more light particles, thus resulting in higher dynamic range and higher light sensitivity.

Actually, if you are using a digital sensor at its native sensitivity, it really doesn't matter much whether you have little pixels or bigger pixels, they are all about the same sensitivity, and will yield the same amount of (very little) noise.
It is when you get into the higher amplification, high ISO situations that the less densely packed, larger pixels start showing a bigger and bigger advantage, because they produce less unwanted noise at the same level of amplification.

 

[lxdude]

Could it be that crop sensor manufacturers just "advertise" their lenses at F1.8, F2.8 or whatever equivalencies just to marketing purposes? And that this doesn't apply to Medium format. I don't see any other reason for it to be that way. So in reality an F1.8 ASP-C lens is an F2.7 lens and they are just marketing "equivalencies". I don't even know how they are applying F-stop in this case to the crop sensor.

They do not.

5.6 is always 5.6, and gives the same exposure regardless of type of lens, focal length, or format. The clue to this is the term you used: crop sensor. Put a full-frame Nikon lens on a crop sensor Nikon camera, and the only difference is that the whole image will be smaller than it is on full-frame, but any object in the image will be the same size. All that has happened is that the full-frame image has been cropped. No change in exposure. At the same ISO and shutter speed, a full frame lens and a crop sensor lens will give the same exposure at the same f-stop. Put a crop sensor lens on a full-frame body, and at a given f-stop, the exposure will be the same as with a full-frame lens. The difference will only be that the crop sensor lens will not cover the full frame.

A given f-stop on smaller and larger format lenses always produces the same exposure under the same conditions, if the shutter speed and ISO number do not change.
For example: Pentax made cameras in 35mm format, 6X4.5cm format, and 6X7cm format. For each of those formats, they made a 200mm f/4 lens. The lenses have the same focal length and aperture number. The 645 format lens is physically larger than the 35mm format lens, and the 6X7 lens is larger than the 645, but the maximum aperture of each lens is physically the same. And the diaphragm opening at say, f/8, is physically the same in all three lenses. The difference between them is that they create different size image circles, depending on the format they cover.
Pentax made adapters for the 645 and 6X7 lenses so they could be adapted to a smaller format. Pentax 645 lenses could be adapted to Pentax 35mm cameras, and Pentax 6X7 lenses could be adapted to both Pentax 645 and Pentax 35mm cameras.
All three formats' 200mm f/4 lenses, on a 35mm camera, give the same image on the 35mm frame. At a given f-stop, all three give the same exposure and depth of field. All the 35mm camera did was crop the larger format lenses' larger image circles more than its own lens's image circle.

All three 200mm f/4 lenses are telephotos in their respective formats, making this example straightforward. But on the larger formats, 200mm is less of a telephoto. On 6X7 it is equivalent to 100 mm on 35mm format. Its optical design gives it a wider angle of view, and it is that wider view that fills out the larger format to its edges. A 50mm lens for 35mm format has a "normal lens" optical design, as does a 100mm lens for 6X7. But on 6X7, a 50mm is a wide angle lens, and has a wide angle design. Still, adapted to a 35mm camera, it will give an image the same size as the 50mm lens for 35mm format, and the same exposure for a given f/stop.

 

[lxdude]

I know for camera sensors, for example a micro 4/3 sensor is less sensitive to light than a full frame (35mm equivalent) sensor. At the same aperture and shutter speed, a full frame sensor is capable of much better low light performance because it takes in more light.

How about medium format, is it more light sensitive due to having a bigger "sensor" or "contact area"? For example, a 75mm 4.5 medium format lens, does it take in the same light at 4.5 as a 75mm 4.5 35mm film camera lens? Or more light?

A medium format lens of a given aperture takes in more total photons, because it has to cover a larger area. But the number of photons per unit of area, say, per square millimeter, is the same as with a smaller format lens of the same aperture. So exposure is the same.
If you masked the medium format film frame so that light could only hit a 24X36mm area, exposure would not change compared to having no mask even though the film area is much smaller. With the same ISO film, the medium format exposure time at for example, f/4.5, would be identical to a 24X36 (35mm) camera with its lens at 4.5. The same number of photons hit a given area at a given f/stop, regardless of format or focal length.