Focal length advice please

[Nick_3536]

Whats the widest lens you have now?

[Richard Wall]

My widest lens is a 90 and I have only rarely wanted something wider. I have done a lot of interiors with the 90, but outdoors the 90 starts to get a little short. When shooting landscapes I often find myself wanting something just a bit longer, around the 135-150 range.

r.

[timparkin]

I spent some time recently trying to come up with a definitive answer to this question (or at least try to get somewhere close).

The first thing was to make sure we really know the size of a large format and a 35mm photography. Well I thought this would be easy but there was a surprise in store. The 35mm size was not 35mm (but I think I knew this). The size was actually 36mm x 24m (35mm was the size of the width of the film strip).

You would expect large format film to be 4" x 5" but actually it's not this, it's 3.74"x4.72" (or 95mm x 120mm). This means the aspect ratio is actually 1:1.26 and you lose over 10% of the film area you thought you had :-(

So... the ratio between LF and 35mm can be calculated based on three things. The first is comparing by short dimension. This is the method I use as I used to crop my 35mm pictures to 4x5 and I now use a mask. This preserves the short dimension of the 35mm picture size and doing this gives a ratio of 3.96 to 1.

The second way to calculate the ratio is presuming that if you like the amount of landscape you can include with your 35mm camera, you should use the long dimension as as the ratio. i.e. if you decide you want to take a landscape orientation picture and you stand in front of Buachaille Etive Mor and want to get the whole mountain in, then you'll want to get the whole mountain in with 4x5 too.. So you'll need the longer side of the aspect ratio to convert properly. This gives a ratio of 3.33 to 1.

The ratio that most people use however is the diagonal. I haven't seen a single justification for this apart from "It uses bits of the short and bits of the long dimension". Anyway, this gives, 3.54 to 1, which is probably the ratio a lot of people recognise.

In summary: -

short dimension comparison gives ~ 4 : 1
long dimension comparison gives ~ 3.33 : 1
diagonal dimension comparison gives ~ 3.5 : 1

Whilst I was doing this I also used google docs spreadsheet program to calculate a few more things, like what lens distribution would you get it you use 40% spacing of focal length and worked from a 150mm lens? What ratios do Leica and Nikon recommend (based on a posting at LFP.info)? What happens if you use 40% difference in angles instead?

Visit this google spreadsheet to see my calculations.. If you want a copy of the spreadsheet just ask or I think you may be able to copy it from the google site.

I should say that the common consensus seems to be to choose your lenses so that the spacing is approximately 40% by focal length. If you want to carry less lenses, use 50%.

As an example from my spreadsheet. If we start with 150 and 210 as a couple of focal lengths that have a lot of common lenses in, we get the 40% ratio and the extrapolated focal lengths in this range would be 77, 107, 150, 210, 294, 412 or if we map to real lenses this would be 75, 110, 150, 210, 300, 400.

I chose to use slightly longer spacing at the top end and slightly shorter spacing at the bottom end. Thinking about this since, I think it might be more useful to have closer spacing at the top end. The reason is that most uses of longer lenses are to pick out details at a distance and it's harder to 'use your feet' when you are working in a 3D environment, for instance if you are on the side of a hill looking down a valley, moving 30% closer to the other side of the valley changes your viewpoint somewhat. My lenses are 80, 110, 150, 240, 360, 500 which give ratios of 40%, 40%, 60%, 50%, 40%. The gap between 150 and 240 is a bit long, I could do with a 190 or 200 to plug the gap but my pack is heavy enough as it is :-)

Joe Cornish uses (from the first light book) 58, 72, 90, 120, 150, 210, 300 (although I doubt he uses all of them at once!) which gives 25%, 25%, 33%, 25%, 40%, 43%. The steps are longer at the top end which is probably because these lengths are used a lot less frequently by Joe (although by his own admission he rarely takes out the 58).

Hope you don't mind me posting verbatim from my blog.. I've posted something else with some pictures to illustrate. The two postings are :

http://blog.timparkin.co.uk/2008/03/...ts-pt-iii.html
http://blog.timparkin.co.uk/2008/03/...continues.html

Tim

[Ron Marshall]

I compared 35mm to 4x5 using horizontal angle of view.

47mm same as 14mm on 35mm.

55 same as 16.5

58 same as 17

65 same as 19

75 same as 22

90 same as 27.5

Having different aspect ratios, 35mm and 4x5 shots with the same horizontal angle of view will look somewhat different, but it gives you some idea of what to expect.

[John Kasaian]

What Bruce Watson says

If you're just putting together your kit, try a more normal lens first if you can't borrow or use someone else's camera. Wide on a view camera is really really wide. Wide often means less movements, too. Unless you are seriously into architectural photography where 90mm are the bomb, wouldn't suggest anything wider than a 135 or 120mm for your first lens. If that starts feeling cramped after a year, you'll have a better idea of how wide you'll really want to go and spend accordingly.
My 2-cents anyway.

[Hany Aziz]

I'm gradually purchasing my large format gear but I'm not sure which wide lens to get. I'm interested in landscapes so was thinking of either a 47mm or 58mm. Am I right in thinking the 47mm is about equal to 17mm on 35mm and the 58mm equal to 20mm 0n 35mm?
If so, would the 47mm start to give some sort of mild fisheye effect?

I would start with a 135 mm lens for landscapes. Add a 210 mm lens as your second lens. Then maybe add a 90 mm later. I do own a 75 mm lens but very rarely use it (too wide). The 58 mm and 47 mm lenses sound ridiculously wide to me. If you insist on a wide lens then you could start with a 90 mm, but I would not start any wider.

Sincerely,

Hany.

[audioexcels]

The practice of thinking in terms of 35mm equivalents is not always a useful way to consider LF lenses, especially when thinking wide. Most folk just 'see different' when shooting LF. Also, how often do you really use a lens wider than 24-28mm in 35. If like most people it is very seldom then you will likely use a 47 or 58 even less in 4x5. My 58 A XL is absolutely my least used lens. I use a 75 with reasonable frequency and suggest you try that before thinking wider. Ken is also right that many never want shorter than 90mm.

I find the 75 is an excellent length, but the 65 or a tad wider adds that extra bit that the 75 doesn't do, though the 75 is a nice focal length. I think it has a lot to do with where exactly one is going to be shooting, the context, etc. My vote would be the 72XL. Great compromise and loads of IC to work with. At the same time, for starters, the Nikkor 90/8 would be a light and excellent choice to get an idea. Guy from the Schneider site (engineer?) prefers the 72XL as his primary wide and it is understandable why...close to 75mm, not quite that extension of the 65mm, but still 3mm's less is quite a lot, though the IC is what is truly beneficial, even on 5X7/4X10 sheet of film...

[audioexcels]

I would start with a 135 mm lens for landscapes. Add a 210 mm lens as your second lens. Then maybe add a 90 mm later. I do own a 75 mm lens but very rarely use it (too wide). The 58 mm and 47 mm lenses sound ridiculously wide to me. If you insist on a wide lens then you could start with a 90 mm, but I would not start any wider.

Sincerely,

Hany.

I think it really depends. Try using a 135mm on the Pacific coastline and get in the very difficult proportions with the rocks/cliffs/ocean/etc. A 47-55mm lens would be my only guess at what could manage to get the scene in "if" you can somehow pull off movements with lenses that don't have any...

For people that live out in flat states or landscape that doesn't involve the West Coast ocean (aka N. Cali-on up), then 135mm makes plenty of sense. Then again, what about waterfalls and getting an entire scene in instead of just the waterfall. There's no way one can get tight corridors in countries around the world such as Italy without a very wide lens.

Again, it depends on the context one is going to shoot and where the person will primarily use their lenses.

I'd rent the wider focal lengths and just get an idea out in the field what they look like...can even do it in a home...

[tgtaylor]

For a one lens kit, I'd consider the Rodenstock 150mm apo-sironaS. It's a little pricy as far as the normal lens goes, but its sharp as a tack and has a 75 degree angle of view which gives you about the same perspective as a 35mm lens on a 35mm camera. If you find that you need to go wider, then you will probably find that a 90mm will be sufficient for most, if not all, of your wide-angle requirements.

I own the 150mm mentioned above as well as a 90mm and 75mm (both f4.5 Rodenstocks) and find that VERY few landscapes require wider than 90mm. That said, your visualization or 'seeing' could demand lenses wider that 90mm and a 75mm takes up very little pack room and weighs way less than the 90mm. Otherwise lenses wider than 90mm just end up sitting unused in your pack.

With architecture, especially indoors, its a different story: Get a 75mm and (since I don't own one) possibly a 65mm Nikkor.

Thomas

[Ole Tjugen]

Much of the time, when I use a 90mm lens on 4x5" I wish I had brought the 5x7" camera instead. So I've bought a 65mm and a 47mm.

But my local landscapes tend to be "tight", and it's very often impossible to take a step back. Even if I can take a step back, it still doesn't help when the mountain I'm right up against is 1600m high and I'm at sea level, or near that.

I have been out shooting with only one lens a couple of times, and have found that for me the best "single lens kit" is a 120mm f:6.8 Angulon! Slightly wide, with lots of coverage for 4x5" so I can use shift and rise all I want, yet small and light enough not to add to the weight of the pack. If I could bring a heavier lens, I'd much rather have several small lenses...