Normal 8x10 lens.

[soupdragon]

Hi guys.

What is considered to be the normal focal length for a 8x10 camera?
AKA 50mm on 35mm film = ???mm on 8x10.
I only have one lens that covers 8x10 format which is a 240mm Schneider APO.
This seems quite wide in use and today was giving me focus/distortion problems.

 

[Terry Jones]

I can't comment on the difficulties you are having with the Schneider but 300mm seems to be the "normal" size for 8x10.

 

[soupdragon]

I'm currently looking at a Nikon W 360 6.5 which seems commensurate with the format.

 

[Terry Jones]

From what I gather, anything from 260-400mm should be acceptable.

 

[jhotopf]

I was looking at a 360mm lens for 8x10 LF. That's the lens used by Richard Avedon for a lot of his work on this format.

 

[Dave_P]

Ignoring the issue that 50mm on 35mm film actually being a bit too long for normal...... then about 300mm is normal for 10x8" - same as 150mm on 5x4". If you find 50mm bang on for your use then you could try for a 360mm, although conversely 180mm is oddly unpopular on 5x4" (probably cos of the Copal 1 sized shutter).

 

[thronobulax]

Hi guys.

What is considered to be the normal focal length for an 8x10 camera?
AKA 50mm on 35mm film = ???mm on 8x10.
I only have one lens that covers 8x10 format which is a 240mm Schneider APO.
This seems quite wide in use and today was giving me focus/distortion problems.

A common first order approximation for normal is the diagonal of the film format. That diagonal distance also describes the minimum image circle size that will cover the format.

That makes it about 325mm for a 10x8 format camera.

However, there is nothing magical about this rule-of-thumb. Depending on how you shoot, and what, lenses far shorter- and longer can be profitably used. For example, tabletop work often uses a longer lens, and landscapes shorter lenses.

Using a 240mm lens should be no problem IF it has a large enough image circle to cover 10x8 with room for some movements. The 240mm f/5.6 APO-Symmar has an image circle of 352mm which is just a tiny bit over the aforementioned 325 mm diagonal. i.e. That lens should cover with limited movements. Note that just because a lens has an image circle that can cover, it may not be sharp and evenly illuminated edge to edge. That's why we prefer lenses with image circles comfortably larger than the diagonal distance of the film.

 

[Nas]

I find 360mm is a nice focal length on 10x8 but it's a heavy lens and the front filter thread is massive, making the use of filters rather expensive.

 

[MartyNL]

8x10" to 35mm equivalent
240mm is equivalent to 35mm
300mm is equivalent to 44mm
360mm is equivalent to 53mm
450mm is equivalent to 66mm

 

[MartyNL]

I don't know what your Nikon 360mm f6.5 is going to set you back...
https://wycameras.com/products/8x10-nikon-360mm-f-6-5-nikkor-w-copal-3-exc

But if you're in the market for a 360mm for 8x10" there's one at Ffordes.
https://www.ffordes.com/p/SH-28-075420/large-format/360mm-f68-symmar-s

The thing is, this is EXACTLY how I got mine. Meaning, the photo and the description didn't match!
I sent an email pointing out the discrepancy in the listing and asking for clarification. The rest they say, is history...

 

[MartyNL]

This is the discrepancy...
The image shows a Schneider symmar-s 360mm f6.8 in a black copal shutter.
While the text talks about a "Sinar 360mm F6.8 Symmar S. Fitted onto Sinar lens panel, without shutter unit, covers 10x8 format"

Giving the impression that the lens has no shutter and is on a Sinar DB lens board to work with a Sinar behind the lens shutter.

I'm not trying to feed your GAS honestly!

 

[thronobulax]

This is the discrepancy...
The image shows a Schneider symmar-s 360mm f6.8 in a black copal shutter.
While the text talks about a "Sinar 360mm F6.8 Symmar S. Fitted onto Sinar lens panel, without shutter unit, covers 10x8 format"

Giving the impression that the lens has no shutter and is on a Sinar DB lens board to work with a Sinar behind the lens shutter.

I'm not trying to feed your GAS honestly!

<Sings in a Beatles way> Cause I', the GASman, Yeah, I'm the GASman...

 

[David M]

The conventional “standard” focal lengths are 50mm for 35mm; 80mm for square format 120 film; 150mm for 5x4 film and 300mm for 10x8 film. These are by no means exact equivalents. They are convenient roundings. ln any case, different format shapes make a difference to how the image is perceived.
There seem to be people who claim that only a focal length that matches the film diagonal can be considered the “true” focal length for that format, giving an exact match to the natural field of view of the human eye, but I can’t see why that should be so. All our eyes differ, as do our heights. There is no debate that I’m aware of, over the true height for a tripod to duplicate natural human vision in the same way.
This idea of the supposedly natural view is only true when viewing a print under specific conditions anyway.

There are two kinds of circle for lenses. Firstly, there’s the circle of illumination - the whole patch of light cast by the lens.
Then there’s the image circle, which defines the area inside which the manufacturer decides that the image is of sufficiently high quality. Very often for LF, this is decided rather cautiously and may be exceeded by the photographer. How much significant detail is there in the top corners of a clear blue sky anyway?

 

[soupdragon]

Thanks guys.
It seems as if it's a contentious issue for some (none here obviously).
From what I can gather, anything between 300 and 400 mm is a roughly standard length.

 

[David M]

I found that it’s best (and cheapest) to start with whatever you’ve got and just take note of how often you find yourself wishing you could get a bit more in or a bit less in. That should be a good guide to your next lens and and perhaps the one after that. Although it’s tempting to translate from your former, smaller camera usage, the larger camera and its modus operandi will almost certainly modify your opinion.

 

[thronobulax]

Thanks guys.
It seems as if it's a contentious issue for some (none here obviously).
From what I can gather, anything between 300 and 400 mm is a roughly standard length.

I'm not sure exactly how "normal" lens length came to be thing. Maybe it's related to the fact that the format's diagonal is the minimum diameter circle of coverage that will cover the negative, I don't know.

But that normal length isn't otherwise special. I find a 35mm lens much closer to how I see things when using 35mm film. On 5x4, I find myself reaching for a 210mm lens most of the time.

All that is to say you should find a focal length that best matches your visualization for a given format. I wouldn't worry about finding the "right" focal length or trying to match to analogous 35mm lenses.

 

[soupdragon]

I'm not sure exactly how "normal" lens length came to be thing. Maybe it's related to the fact that the format's diagonal is the minimum diameter circle of coverage that will cover the negative, I don't know.

But that normal length isn't otherwise special. I find a 35mm lens much closer to how I see things when using 35mm film. On 5x4, I find myself reaching for a 210mm lens most of the time.

All that is to say you should find a focal length that best matches your visualization for a given format. I wouldn't worry about finding the "right" focal length or trying to match to analogous 35mm lenses.

By all accounts it came about from the angle of view the human eye.
My guess is 46 degrees.

 

[thronobulax]

By all accounts it came about from the angle of view the human eye.
My guess is 46 degrees.

I've heard this before, but it's kind of a folk myth. In reality, the human horizontal angle of view is far, far larger than, say, a 50mm Summicron whose horizontal angle of view is about 40 degrees.

A 35mm Summicron has a horizontal angle of view of 63 degrees, which is much closer, but still not as wide as the human eye.

How about a 21mm Elmarit-M. It has a very nice 81 degree horizontal angle of view and still doesn't match the human eye.

As the article cited below points out, you'd have to get down to about a 10mm lens on a 35mm format camera to match the human field of vision.

This is why I never much took the "this is the normal lens" stuff very seriously. I chose (and choose) my lenses according to what- and how I shoot. In truth, the nominally "normal" ones in each format get the least use. In 35mm, for all systems, I use 35mm and 21mm more than anything else. In 6x6. I reach for the 60mm Distagon on my Hasselblad first. On 5x4 it's kind of a tossup across a variety of choices: 127mm Ektar, 207mm Ektar, 150mm APO Symmar, 210mm Caltar-II, and 8 1/2" Commercial Ektar, depending on which camera I am using and what the scene is.

Having said all this, there ARE differences in focal lengths unrelated to angle of view. All things being equal, longer lenses have less Depth Of Field being chief among them.

Citation: https://pixelcraft.photo.blog/2019/08/16/is-the-eye-equivalent-to-a-50mm-lens/

 

[soupdragon]

I've heard this before, but it's kind of a folk myth. In reality, the human horizontal angle of view is far, far larger than, say, a 50mm Summicron whose horizontal angle of view is about 40 degrees.

A 35mm Summicron has a horizontal angle of view of 63 degrees, which is much closer, but still not as wide as the human eye.

How about a 21mm Elmarit-M. It has a very nice 81 degree horizontal angle of view and still doesn't match the human eyes.

As the article cited below points out, you'd have to get down to about a 10mm lens on a 35mm format camera to match the human field of vision.

This is why I never much took the "this is the normal lens" stuff very seriously. I chose (and choose) my lenses according to what- and how I shoot. In truth, the nominally "normal" ones in each format get the least use. In 35mm, for all systems, I use 35mm and 21mm more than anything else. In 6x6. I reach for the 60mm Distagon on my Hasselblad first. On 5x4 it's kind of a tossup across a variety of choices: 127mm Ektar, 207mm Ektar, 150mm APO Symmar, 210mm Caltar-II, and 8 1/2" Commercial Ektar, depending on which camera I am using and what the scene is.

Having said all this, there ARE differences in focal lengths unrelated to angle of view. All things being equal, longer lenses have less Depth Of Field being chief among them.

Citation: https://pixelcraft.photo.blog/2019/08/16/is-the-eye-equivalent-to-a-50mm-lens/

Cool.
What seems to be overlooked is that the human eye scans horizontally faster than vertically.
This gives the illusion of sight having a wider angle of view.

That could be total nonsense of course.

 

[finishthat]

There is a phone app called Viewfinder which allows you to set the film size - including 10x8 and the lens mm to give you a preview of what you will get includes a light meter as well - it takes a bit of fiddling to add your lenses and film/sensor sizes . It’s a bit tedious looking at it indoors but if you set it up and pick an outdoor subject it will give a useful indication of what you actually get without having to guess and let you target your lens GAS with less remorse ;-)