First medium format purchase

[benwheeler]

After being seduced by full frame a few years ago (my beloved 5D), I'm now looking at trying my hand at medium format. This has mainly come about because I want high quality pics of some furniture I've built, and I only recently discovered the advantages that MF has in terms of lack of distortion compared with 35mm.

My current thinking (trying to get maximum bang for buck) is to acquire a Mamiya RB or RZ67 with a 50mm lens. I'd be happy to hear any thoughts about the camera choice, as well as anything related, ie is 120 film likely to be around for a while? Is there a reason there are hardly any recent posts on this forum about medium format?

[safegrass]

I think you're pretty safe with availability of 120 film, whilst Fuji seem to be culling their offerings, companies like Kodak and Ilford are going well (assuming you're happy with black and white).

I used to have an RZ67 and loved it. Only reason I sold it was because I do a lot of hiking/photography trips and that camera is HEAVY! I think the RB is heavier?

50mm on medium format is reasonably wide, 80mm is a useful lens to have as well ("normal" on MF).

Other thing to note on the RZ is that using a normal shutter release cable, max exposure is 30 seconds. If you shoot landscapes or dark scenes you'll easily be pushing that by the time you count reciprocity failure.

Good luck with your search!


Sent from my iPhone using Tapatalk

[enseth]

Hasselblad have just released a very nice 100 megapixel medium format camera. It'll only set you back $25k (US).

[swifty]

Can you elaborate what you mean by "MF has lack of distortion compared with 35mm''?
Do you mean that generally speaking, lens made for MF tend to have less distortion?

[Lance B]

After being seduced by full frame a few years ago (my beloved 5D), I'm now looking at trying my hand at medium format. This has mainly come about because I want high quality pics of some furniture I've built, and I only recently discovered the advantages that MF has in terms of lack of distortion compared with 35mm.

My current thinking (trying to get maximum bang for buck) is to acquire a Mamiya RB or RZ67 with a 50mm lens. I'd be happy to hear any thoughts about the camera choice, as well as anything related, ie is 120 film likely to be around for a while? Is there a reason there are hardly any recent posts on this forum about medium format?

Hmmm. I don't think that there is any less or more distortion with 35mm rather than MF, it depends on the lens and focal length.

I am also not so sure you will actually end up with better results than going to a high MP 35mm camera like the D810, Sony A7 RII, or Canon 5DS R or 5DS.

[benwheeler]

Thanks for the responses. I knew I hadn't been clear when taking about 'distortion' :-/

What I meant is that if, for example, I needed to photograph a large piece of furniture in a small room, on my DSLR it might require a 24mm lens, which would look quite distorted. On a 6x7 camera, the equivalent lens would be a 50mm to achieve the same field of view.

Also, whereas I do have $4-600 for a MF camera, I definitely don't have $3.5k for a 5DS..

[Dug]

The way I picture it is a 50mm on a 6x7 camera will not magically have the perspective characteristics of a 50mm on a DSLR at the same time as seeing the subject with a wider angle of view than a 50mm DSLR lens, if this is the way you are interpreting things.

It is the angle of view that will determine the distortion not the focal length.

Get a 24mm tilt shift lens for your 5D might be a better answer. But not a cheap one.

[fillum]

If I understand correctly Ben, your issue is with the perspective caused by shooting your subject from a close distance. If that's the case a change of format won't help here. Perspective is dependent on where you place the camera relative to your subject. So a different format or different lens shot from the same position will still show the same perspective. (Other things may change, field of view for example, but perspective will be the same).

Options:-
- put more distance between the camera and the subject
- alter the perspective in post production (might look ok, might not)
- I don't know enough about tilt-shift lenses to know if one would help in this scenario - hiring one might be an option



Cheers.

[ricktas]

As said, distortion is not just related to the lens, the sensor (film) size, distance to subject and angle taken from all contribute.


Is there a reason there are hardly any recent posts on this forum about medium format?

yes! Cause of the 22,000 members of the site you would probably find less than 20 with a medium format camera. DSLR and mirrorless are the dominant cameras in the world today (not just on AP) and as such most discussions revolve around those. Bit like going on an Aussie car forum and asking about people who have driven a Bugaytti Veyron. You will likely find a few.. but not many.

However, there are a members here who have MF (me included) but we also have DSLR etc and you will find the MF camera is not used anywhere near as much as a DSLR, by most of us. Simply out of convenience. MF cameras can produce amazing quality prints. Can I ask if you have shot with film before? Cause it certainly changes the way you shoot. You cannot fire off 20 shots hoping to get a keeper. My best advice would be to go to a second hand camera dealer and grab an slr, put some film in and start practicing.

Good luck and if you do go the MF, you will enjoy the learning experience and the quality results that it can produce.

[benwheeler]

The Bugatti comment is gold! I take your point. I have shot a bit of film, and should probably do more so since I've got a Canon 35mm body sitting in the cupboard, ready to match my 5D lenses!

Regarding the issue of distortion, some of the remarks in this thread are in direct contradiction to the things I read on various sites that led me down this path in the first place.

Here's a good example from this webpage - http://reframe.gizmodo.com/why-medium-format-is-so-gorgeous-its-about-more-than-r-1601938278

"But print size aside, it's often easy to detect medium format images even when viewing on the web. It has a certain something, a signature look that is often recognizable but hard to articulate. It comes from the lack of perspective distortion. This makes photos look more natural, closer to what your eye sees in the real world.

Let's say you're shooting on a 6x7 medium format camera with a 50mm lens. If you compare your images to a 35mm camera, also with a 50mm lens, you will notice the difference in field of view. Your medium format pictures will actually see what a 24mm lens on a 35mm camera would see. Simply put: the larger the film format, the wider angle your lenses become compared to 35mm.

The key point as a result of that difference is that even though the field of view is wider, the geometry, or "look," of the 50mm focal length remains. You don't get the exaggerated perspective that wide angle lenses usually produce on 35mm cameras. In that regard, medium format mimics how your eyes actually see the world, at least more so than the smaller 35mm size. The effect is even more apparent with large format 4x5, 5x8, or 8x10 film. You can shoot an extremely wide scene but it will have the "real-world" look of a lens with a longer focal length. The subject remains flat and not 'stretched' out."


I'd certainly be interested to hear any disagreement with that point of view! It's unfortunate that the cost of hiring a MF setup is not too far removed from that of buying it, or I'd do that first..

[swifty]

I must admit I'm not entirely clear what the answer is.
For quite some time I had subscribed to what your referenced article states. However, in practical situations through personal experience with various sensor formats, it is the angle of view that changes perspective. I'm tempted to say irrespective of format but this is where the theory gets a little fuzzy.

Bear with me for a second.
Assuming a subject that is 1m from your camera and is 2m wide. You frame your image to just incorporate the entire subject.
So with various sensor/film formats, you'd need different focal length lenses to achieve the same framing. The smaller the sensor/film format, the wider the focal length.
But you achieve the same perspective even with different focal length lenses regardless of sensor/film format because the angle of view hasn't changed, or has it?
I can only assume the angle of view is a measurement taken from the edge of the scene to a point in the centre of the sensor/film in which case the angle of view stays the same regardless of sensor format. This is possibly a wrong assumption.
But in reality the scene is not captured this way. The edge of the scene will be captured at the edge of the sensor/film whilst the centre of the scene is captured at the centre of the sensor/film. So the angle of view as measured from the edge of the sensor/film to the edge of the scene does change as your sensor/film size increases.

I was always taught to extrapolate to a more extreme scenarios to help illustrate a point.
So lets assume we now compare the same example scene captured with a miniscule digital sensor, something you might find in a phone camera. Same camera and subject position but using different lens of different focal lengths to achieve the same framing to just incorporate the entire subject within the frame.
Compare that to a gigantic camera where the film size is 2m across. Ie. The film is the same size as our subject and the image will be captured at 1:1 on this theoretical giant camera. Its not hard to imagine on this giant camera the light rays are almost parallel at all parts of the scene resulting in theoretically zero perspective distortion.
And in the tiny camera scenario the light rays in the centre will vary greatly with the light rays at the edge.

So what's my conclusion, I'm tempted to say format does make a difference but you'd be hard pressed to see a difference unless the difference in formats are very large. Will there be a difference between FF and APS-C, probably hardly noticeable.
How about FF and 8X10 large format - then absolutely. Between FF and 645, probably not much but likely when you go to 6X7.
You'd probably notice much bigger differences in DOF and less in terms of perspective changes.

Anyways, that's just me applying some layman geometry to try and get my head around the conundrum. Feel free to poke holes in my theory.

In the mean time, try the Brenizer technique if you don't mind stitching in post processing. Its akin to using a much larger sensor and will be ideal on a stationary object but live subjects are also very doable as the man himself demonstrates.

[jjphoto]

...Regarding the issue of distortion, some of the remarks in this thread are in direct contradiction to the things I read on various sites that led me down this path in the first place.

Here's a good example from this webpage - http://reframe.gizmodo.com/why-medium-format-is-so-gorgeous-its-about-more-than-r-1601938278

"But print size aside, it's often easy to detect medium format images even when viewing on the web. It has a certain something, a signature look that is often recognizable but hard to articulate. It comes from the lack of perspective distortion. This makes photos look more natural, closer to what your eye sees in the real world.

Let's say you're shooting on a 6x7 medium format camera with a 50mm lens. If you compare your images to a 35mm camera, also with a 50mm lens, you will notice the difference in field of view. Your medium format pictures will actually see what a 24mm lens on a 35mm camera would see. Simply put: the larger the film format, the wider angle your lenses become compared to 35mm.

The key point as a result of that difference is that even though the field of view is wider, the geometry, or "look," of the 50mm focal length remains. You don't get the exaggerated perspective that wide angle lenses usually produce on 35mm cameras. In that regard, medium format mimics how your eyes actually see the world, at least more so than the smaller 35mm size. The effect is even more apparent with large format 4x5, 5x8, or 8x10 film. You can shoot an extremely wide scene but it will have the "real-world" look of a lens with a longer focal length. The subject remains flat and not 'stretched' out."


I'd certainly be interested to hear any disagreement with that point of view! It's unfortunate that the cost of hiring a MF setup is not too far removed from that of buying it, or I'd do that first..

Seriously, the article you linked to is just an opinion and there is nothing in the article to even support the arguments made in it. I disagree with pretty much all of it, see below. I've used an RZ with a 50mm lens for about 20 years and still have the gear, I just see no point in using it any more, except for B+W prints.

From the article you linked to;

"It's well known that medium format offers an increase in resolution and print size,"

Only over smaller film formats. Modern digital cameras easily out resolve most medium format films and lenses (depending largely on the film stock that is still available today). I found my 16Mpx Canon DSLR produced equivalent resolution images in magazine publications as did 6x7 Mamiya RZ images shot on Velvia (which were drum scanned professionally by the printers). B+W chemical prints from the RZ are stunning because of the amazing tonal gradation, which seems hard to get with digital, but aside from that I see no advantage with medium format. Large format is another matter.

"It has a certain something, a signature look that is often recognizable but hard to articulate."

It certainly does have a certain ‘I-don’t-know-what’ about it but probably not the way you think it has. Many films have a 'look' that may be considered attractive or special. On the other hand when digital has a 'look' it's often because the colours are wrong or undesirable. Scanning film is a black art and you have no way of knowing how much of what you see on the internet is due to the film itself, the choices made during the scanning process, or anything in between. I don’t think you can generalise and say all medium forma has a recognisable ‘look’, unless you are referring to the dust on the film or the aspect ratio of the film. I can crop my digital files to 6x6 if I want, I just don't want to.

“It comes from the lack of perspective distortion. This makes photos look more natural, closer to what your eye sees in the real world. “ and "You don't get the exaggerated perspective that wide angle lenses usually produce on 35mm cameras."

Not true, actually it's rubbish. Perspective and Distortion are two different things. Perspective has nothing to do with the lens, it's focal length or optical design. Perspective is determined entirely by the location of the lens, or to be exact, the front Principal point or Entrance pupil (I believe they are the same but am happy to be corrected, I just can't be bothered referring to my text books about it) of the lens. If you want to learn about perspective then I suggest you read Rudolf Kingslake, ‘Lenses in Photography’ where perspective is discussed in detail.

By the way, Distortion is caused by the optical design of the lens (aperture placement plays a big part), Perspective by the location of the lens.

“The key point as a result of that difference is that even though the field of view is wider, the geometry, or "look," of the 50mm focal length remains. You don't get the exaggerated perspective that wide angle lenses usually produce on 35mm cameras.”

I don’t see any argument in the linked article to support the view that perspective would be different. Saying it doesn’t make it so.

Taking the example of a 50mm lens on an RZ, this lens is a retrofocus wide angle lens which is a type of lens used when the rear element of the lens has to be a large distance from the film plane so that it can clear the mirror in the body. The 50mm RZ lens has a field of view equivalent to a 24mm lens in the 35mm film format which is also a retrofocus lens because it also needs to clear the mirror in a 35mm reflex body. If you shoot the same subject from the same location with these two lenses on their respective formats you will get the same perspective and almost certainly the same or similar distortion, notwithstanding differences in optical designs from one lens to another (even a Canon and Nikon 24mm lens will potentially have slightly different distortion to each other).

Using a larger format does change the depth of field in an image, because longer lenses are required for an equivalent field of view to a smaller format, and this plays a part in the look of large format images but more so than medium format.

If I were you I would try to borrow the gear and try it for your purposes because I think you would be disappointed to find it does not do what you think it will.

[swifty]

Hi Jon, I may be completely wrong with my assumptions in my post above.
Do you know how the angle of view is measured and can you shed light (pardon the pun) on my above theoretical model comparing a tiny sensor/film and a giant one?

I think it would be useful to identify we're not talking about things like barrel/pincushion/moustache type distortions which are related to lens design.
For lack of a better term, it's 'perspective distortion' that's the subject of contention here. The type you see between a wide angle vs telephoto lens. If there's a better term for it, please let us know.

- - - Updated - - -

Could the angle of view be measured from the lens nodal point in which case it is irrespective of sensor/film size?

[Lance B]

The Bugatti comment is gold! I take your point. I have shot a bit of film, and should probably do more so since I've got a Canon 35mm body sitting in the cupboard, ready to match my 5D lenses!

Regarding the issue of distortion, some of the remarks in this thread are in direct contradiction to the things I read on various sites that led me down this path in the first place.

Here's a good example from this webpage - http://reframe.gizmodo.com/why-medium-format-is-so-gorgeous-its-about-more-than-r-1601938278

"But print size aside, it's often easy to detect medium format images even when viewing on the web. It has a certain something, a signature look that is often recognizable but hard to articulate. It comes from the lack of perspective distortion. This makes photos look more natural, closer to what your eye sees in the real world.

Let's say you're shooting on a 6x7 medium format camera with a 50mm lens. If you compare your images to a 35mm camera, also with a 50mm lens, you will notice the difference in field of view. Your medium format pictures will actually see what a 24mm lens on a 35mm camera would see. Simply put: the larger the film format, the wider angle your lenses become compared to 35mm.

The key point as a result of that difference is that even though the field of view is wider, the geometry, or "look," of the 50mm focal length remains. You don't get the exaggerated perspective that wide angle lenses usually produce on 35mm cameras. In that regard, medium format mimics how your eyes actually see the world, at least more so than the smaller 35mm size. The effect is even more apparent with large format 4x5, 5x8, or 8x10 film. You can shoot an extremely wide scene but it will have the "real-world" look of a lens with a longer focal length. The subject remains flat and not 'stretched' out."



Sorry, this last paragraph is just not so.

As for "It has a certain something, a signature look that is often recognizable but hard to articulate", all that means is that it may look different, but not necessarily better or more accurate. My 35mm Kodachrome 64 colour slide film certainly has a "look" to it as well, but I will take my D810 images over it any day for realism and "correctness" of reproduction, plus it has waaay more resolution. As Swifty states, the bigger difference with MF is the DOF difference, MF has a much shallower DOF for the same aperture than a FF DSLR and a FF DLSR has a shallower DOF for the same aperture as an APS C DSLR. This DOF difference will also give it a different look.

As for focal length and ange of view, this is directly proportional to the size of the sensor but you must compare apples to apples, ie the same angle of view on MF to that of a DSLR. Focal length is just that and a 50mm lens is a 50mm lens whatever format you use it on. The idea that a 50mm lens (not sure of the angle of view on a 6x7 MF camera) has less distorion than a 24mm lens on a FF DSLR is just not so if we are actually comparing same angles of view. In other words, if the angles of view are the same there will be little to no difference in distortion with either format - depending on the lens designer differences of course. It is the same thing as comparing an APS C 16mm lens to a FF DSLR 24mm lens, both will have similar distortion (within lens designer parameters) as their respective angles of view are basically the same.

jjphoto also has made some excellent points which correspond with my thoughts as well.

[Dug]

It seems to be a commonly held belief when I search for information about it, and tends to come from people extolling the virtues of medium format.
I cannot find a technical explanation given to support it though.

This is my way of looking at it:
Distance to subject determines perspective (and angle of film plane but lets ignore that bit in this comparison).

It requires different focal lengths to have the same angle of view between different formats.

The same angle of view will require the same distance to subject to get the same framing in any format.

Which loops back to same distance to subject = same perspective.

[benwheeler]

Thanks so much for your detailed responses. I'm surprised that the website I linked to, as well as several others, seem to have very incorrect information that's gone apparently unchallenged. Perhaps it's because the subject is quite esoteric and only becoming more so.

One reason why the explanation on that site rang true to me is that I regularly see enormous prints of fashion photography in a retail area where I work, which I'd assumed must have been shot with medium or large format. They have a very expansive feel about them, as if you're in the photo. I'd attributed this difference of 'feel' to the difference in format, which it sounds is incorrect.

I've finally found a source of inexpensive RZ67 rentals (removed, please read the site rules, in particular rules 3-7) so may still try that out to satisfy my curiosity. That aside, it sounds like I just need to manufacture ways to get further from the subject! I'm also interested in this Breziner technique, although I'm unsure if it will be appropriate for my application.

Thanks again.

[Lance B]

I think that where all this gets muddled up is that MF has the potential to have leading image quality but doesn't because less research and development goes into those sensors and camera, simply because there is little demand for them when compared to FF and APS C sensored cameras. The other issue with such large sensors is the yield rate that sensor manufacturers get from such large sensors is very, very low when compared to smaller sensor sizes. Even FF DSLR sensor yield rates are quite low compared to APS C sensor yield rates and hence why the large pricing disparity between even FF cameras compared to APS C cameras. So, it's not that MF shouldn't have better overall IQ, just that economies of scale dictates that sensor development is not as advanced, not to mention the cameras that they go into are also less advanced as well due to lower economies of scale.

[ricktas]

One reason why the explanation on that site rang true to me is that I regularly see enormous prints of fashion photography in a retail area where I work, which I'd assumed must have been shot with medium or large format. They have a very expansive feel about them, as if you're in the photo. I'd attributed this difference of 'feel' to the difference in format, which it sounds is incorrect.

Most likely taken with a Digital Back MF, or a DSLR. You can have a digital back MF for about $10K. remember that these fashion photographers at the high end, are paid very well and have teams of people work with them to create the final image you see. Often having digital art background (ie not photographed) etc. I doubt any high end fashion photographer uses film these days. A lot of what you see in those enormous prints has been edited to the point that if you saw the original RAW file you would not think they were the same photo.

[arthurking83]

I agree with the naysayers in the thread.

I personally wouldn't waste time and effort with the solution you intend too.

And as for the 'Breziner technique' .. I really don't understand why people use this term.
It's simply and more popularly known as stitching! :confused013

That's the beauty of digital over film .. take multiple thousand images and stitch them all together .. make a gigapano if you dare too!

But that's you best bet I reckon. That is, use a good quality longish focal length macro lens and a panorama/stitch workflow.
It'll be quicker overall and cheaper and the possibilities are more infinite compared to a MF workflow.

Many high quality 90-105mm macro lenses can be had for little expense. Stitching is easy as nowadays with just about all image editing apps having this ability.

Even renting a MF camera just for the sake of achieving a '50mm lens look' seems to be an effort not worth chasing.

The only caveat here is that if you are looking for a challenge, in the sense that an enthusiast would.
If this is the ultimate goal, then I fully understand the reasoning.
But if the ultimate goal is to achieve product shots(of your own making), then using what you have and if needed acquiring a good macro lens and stitching would be the better option.

[ameerat42]

Ben. The following excerpt from that link seems to be the point that "swung" you...

"The key point as a result of that difference is that even though the field of view is wider, the geometry, or "look," of the 50mm focal length remains. You don't get the exaggerated perspective that wide angle lenses usually produce on 35mm cameras. In that regard, medium format mimics how your eyes actually see the world, at least more so than the smaller 35mm size. The effect is even more apparent with large format 4x5, 5x8, or 8x10 film. You can shoot an extremely wide scene but it will have the "real-world" look of a lens with a longer focal length. The subject remains flat and not 'stretched' out."

Well, the interpretation is simple as to "WHY?"
For the SAME FOV using a wide-angle lens on a 35mm camera, the MF (and LF) cameras SHIFT you further away from your subject.
That is: the subject distance is larger, and hence, no distortion (yes, correct term) from differential magnification (q.v.) and other
proclivities pertaining to the smaller format.

So the Q is: have you got room to increase the subject distance?

I see you're new here, so welcome too.

[Dug]

Getting back to your task of photographing furniture with a pleasing perspective.
I take it that in your example comparative focal lengths you use 24mm on a DSLR (FF), so I'm figuring you want to photograph the furniture in a domestic setting that is a bit of a tight space.

If you can get access to someones larger living space that you could get further back with a longer DSLR lens it might be your solution right there.
For that extra quality you want, renting a Canon 5DS @ 50 megapixel for the session is going to have that covered over your 5D @ 12.8 megapixels.

6x7cm film is all very well but you need to scan the result these days to use the image in printed and digital media for wide distribution if these pictures are for promotional purposes.
I'd go with an image straight from camera over a scan any day.

A lot of assumptions here. :)

If you have your heart set on doing med format film then just go for it. The equipment has never been cheaper.
Can't say the same for film and from film printing costs though.

My 6x4.5 film camera sits on the shelf for that reason and I was always disappointed with not having the same control over colour print out come as I now have with digital.

[mongo]

Mongo is not going to get into this argument other than to say:-

- Mongo has used a MF for many years and still owns one
- Mongo agrees with those who have said to you that MF will not make a difference for the reasons you are looking to use it for (and many good reasons have been given to you as to why MF will not necessarily solve your perceived problem)

Good luck with your final decision

[Dug]

I should point out first Ben that as is often the case on photographic forums, posts can turn into a nerd fest and it is not our intention to tell 15 different ways that we are not in agreement with anything you have said or quoted.
It is all in good fun and in the spirit of learning new things and delving into unfamiliar territory.

So anyway I found this field dimension and angle of view calculator thingy.

Into the values I have put the sensor size for a 6x7 camera and for 35mm
I have used 50mm focal length for the 6x7 and 24mm for the 35mm
2m to subject has been used for both calculations assuming you where after a relatively tight framing of a single seat couch chair as an example.

What I intemperate from the results is that though the figures differ in the results window for horizontal, vertical and diagonal values, the 6x7 for example has slightly smaller values in the horizontal and slightly bigger in the vertical and the diagonals average out closely.
This is because the 6x7cm has a different aspect ratio to the film frame than 35mm, 6x7 has a closer to square ration and 35mm is more panoramic by comparison.

On average you would stand at the same distance from the subject with with each of the example camera lens combos and get the same result.
What would give credence to what you read about medium format is that medium format cameras tend to have more head room in the shape of the frame compared to 35mm and therefore with the right shaped subject you could move a bit further back without chopping the top off anything.
This would change the perspective a bit, more so the closer you needed to be.

35mm calculation

http://i695.photobucket.com/albums/vv312/Dug05/resized%20for%20APF/35mm_zpscqpxpdkd.jpg (http://s695.photobucket.com/user/Dug05/media/resized%20for%20APF/35mm_zpscqpxpdkd.jpg.html)

6x7cm calculation

http://i695.photobucket.com/albums/vv312/Dug05/resized%20for%20APF/medium_zpsvsny0zku.jpg (http://s695.photobucket.com/user/Dug05/media/resized%20for%20APF/medium_zpsvsny0zku.jpg.html)

[jjphoto]

...Could the angle of view be measured from the lens nodal point in which case it is irrespective of sensor/film size?

It's my understanding that this is the case, however there are two nodal points in every lens (because the lens has two sides and effectively can be used in either direction although obviously with a different result).



...
I think it would be useful to identify we're not talking about things like barrel/pincushion/moustache type distortions which are related to lens design.
For lack of a better term, it's 'perspective distortion' that's the subject of contention here. The type you see between a wide angle vs telephoto lens. If there's a better term for it, please let us know...


Re perspective distortion. Whether or not there is 'distortion' in the final image depends on the size of the print and viewing distance relative to the perspective in the original image. The reason images shot with wide angle lenses appear distorted is often because the distance from which we view the resulting image is at odds with the perspective in the image itself. If you view the image from closer than the normal viewing distance, or the finished image is much larger (having the same affect as viewing it from closer), you will see that the perspective looks natural or realistic and the 'distortion' has disappeared. So I don't think the 'distortion' happens when the image is taken rather when it is viewed at the wrong print size/viewing distance. Try it. It's explained much better by Rudolf Kingslake (Director of Optical Design at Eastman Kodak) in 'Lenses in Photography' (1951) where the entire first chapter is called and is about Perspective. It's a superb book and worth reading if you're into that kind of thing (optics, lenses etc) although there are lot's of good books on the subject.

[benwheeler]

Once again, I really appreciate all the time taken here to thoroughly explain different aspects of this issue. I'm a nerd deep (ok not too deep) down, so more than happy for a nerd fest. To respond to a few points and questions:

- Most pieces I've made are stand-alone or otherwise mobile, but the one that got me thinking about alternative photographic solutions is a 3.6x2.6m bookcase that takes up a whole wall of a small-ish room. So there's no moving the camera further back - I'll either have to be satisfied with a pretty wide angle shot, or experiment with stitching.

- Why would one need a macro lens for stitching, as suggested in a previous post?


And as a bit of a tangent.. Has anyone come across the Wanderlust Travelwide, a Kickstarter 4x5 camera? Looks interesting. Anyway, I'm still interested in having a crack at either MF or LF at some point, but my immediate need for it seems to have died away thanks to some forceful wisdom :D

[arthurking83]

It should be noted that at a deep down nerd level, the premise that a longer focal length lens will have less distortion than a wider focal length lens will.
There are different types of distortion to comment upon here too.
The main distortion effect we all see in wide angles is geometric distortion, usually seen as barrel, but then as you zoom in with a wide zoom lens it then turns into pincushion type.

Perspective distortion comes in various types as well, you can get the typically seen tilted perspective distortion or vertigo look known as convergence and divergence, where parallel lines converge/diverge depending on the amount of tilt in the camera lens setup. This is easy to correct for with careful setup and can also be digitally corrected for too.
But there's also compression/extension .. and this is where the focal length of the lens plays the largest role in lens distortion .. and can't be accounted for or corrected for in any way.
Compression/extension is a property of the lens's focal length, and hence magnification.

For all distortions other than compression/extension distortion, they can be minimised or eliminated with good practise, and or a solid workflow.
The only distortion that is solely dependent on lens focal length(and therefore format size for the same FOV and framing) is compression/extension.
But at the focal lengths the OP is commenting on, the hassle(of using MF) isn't worth any real benefit.
That is, the perspective distortion with respect to compression effects of a 50mm lens compared to a 35mm lens is minimal at best .. and almost certain to be unnoticeable to just about any and every one.(hence the comment above re the hassle of using MF instead of the 135format that you already have)

YES! there is a distortion difference in a nerdy technical sense, but no you won't really see it.
The compression effect is really only noticeable between focal lengths of great difference(ie. 20mm vs 85-100mm or whatever).

I once did the test(coz I'm also a deep down nerd at heart), where I shot a stitch panorama series of images at about 10-15mm on a UWA lens(about 20 or so images in total .. eg. 4 across and 4 down) and then shot a 200mm-ish reference image to compare.
Image was ugly as it didn't encompass any thought for composition, other than to frame an infinity focal point between two leaning trees at the edge of the frame.
The focal point was infinity and I stood right up in line with the two edge trees and shot (basically) a 180° pano all round with the UWA, and then stood back about 20m or so and the same shot with the telezoom lens(roughly speaking at about 200mm .. maybe 150mm, can't remember exactly).
The difference in actual rendering was stark!
The tele image had the so called background much closer relative to the two trees in the foreground(compression). But the background looked like the main subject in that image.
By comparison(when the images were scaled to the same output size), the pano shot with the UWA lens you could barely make out any detail in the background if you wanted to see the trees(extension), but could 'zoom in' to the same detail level in the background if viewed at 100% pixel zoom level.

Where compression/extension is usually taken into consideration is in portraiture where a longer focal length is usually recommended as a complimentary rendering of the subject.
Nothing to stop you from shooting a portrait at 35mm but the facial distortion will be noticeable if you 'look closely' .. where the nose may appear to be bigger than reality.
Same framing with a 135mm or longer focal length and by comparison the nose will look normal. All this is simply due to compression distortion(which also takes into consideration of extension distortion that an wide angle lens will create). Hence why a portrait lens is usually something like 85mm on a 135 format .. and why larger formats mediums are generally used for portraiture .. longer lens for a FOV.



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- Why would one need a macro lens for stitching, as suggested in a previous post?

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Macro lenses usually produce more clinically accurate images, with fewer aberrations(distortion/CA/field flatness/etc).
No real need for it, and you could easily achieve the same effect with any regular lens of the same focal length .. but a macro lens of repute will give you just a very slight edge in the total rendered image's quality. Flatter field and less geometric distortion from the macro lens should allow you more leeway if you do go down the stitching path.

Here's a wiki type link to a visual representation of perspective distortion
(https://en.wikipedia.org/wiki/Perspective_distortion_%28photography%29)
scroll down to the images of the water bottles.
Note how as focal lengths become closer in ratio terms, the effect of compression/extension is less obvious and problematic.

[Dug]

And as a bit of a tangent.. Has anyone come across the Wanderlust Travelwide, a Kickstarter 4x5 camera? Looks interesting. Anyway, I'm still interested in having a crack at either MF or LF at some point, but my immediate need for it seems to have died away thanks to some forceful wisdom :D

I have seen the Wanderlust Travelwide promotions before.
For me if I was to go to all the effort of loading sheet film for a large format camera I would want to have all the movements of a bellows camera.
The Wanderlust Travelwide is a sort of large format Box Brownie with a nice lens.
The image quality would have all the advantages of the format size, but miss out on what sets the large format experience apart from fixed focal plane cameras.