Re: Is it a linear progression between 90mm and 150mm?
An interesting discussion.
Does anyone want to step into the quick-sand of comparing the L?W ratios of various LF formats with the standard 35mm film format or the several digital sensor sizes?
I think there is relevance to the OP question where angle of view is considered.
Re: Is it a linear progression between 90mm and 150mm?
Quote:
Originally Posted by
Drew Bedo
An interesting discussion.
Does anyone want to step into the quick-sand of comparing the L?W ratios of various LF formats with the standard 35mm film format or the several digital sensor sizes?
I think there is relevance to the OP question where angle of view is considered.
Obviously, the different formats make comparison difficult. How do you compare 4x5 large format to 3:2 full-frame 35mm or 6x7 or 6x6 on 120 film? Here a chart that gives angles of view horizontally, vertically, and diagonally. So you can pick your "poison" when comparing. Personally, I like to compare the horizontal angle because that's how I "see". Also note in this chart, that there are two methods of reading the angles. They provide both.
https://www.pointsinfocus.com/tools/depth-of-field-and-equivalent-lens-calculator/#{%22c%22:[{%22f%22:19,%22av%22:%2216%22,%22fl%22:150,%22d%22:30480,%22cm%22:%220%22}],%22m%22:0}
Also, the angles provided don't match the lists provided in our forums. I suppose that list shows the angle the lens sees. But the part that is recorded in the back of the camera on the film is a smaller angle. Maybe one of our experts here can define the Angles of Coverage column on this chart. Also, what are the other columns for in particular the ones called rise falls, and tilts?
Here's the chart for 4x5. There are others there for the other LF sizes.
https://www.largeformatphotography.i...s/LF4x5in.html
Re: Is it a linear progression between 90mm and 150mm?
Quote:
Originally Posted by
Drew Bedo
An interesting discussion.
Does anyone want to step into the quick-sand of comparing the L?W ratios of various LF formats with the standard 35mm film format or the several digital sensor sizes?
I think there is relevance to the OP question where angle of view is considered.
I think this makes a difference when making focal length comparisons between different formats. But for me, it wouldn't make a difference when deciding on lens progressions.
Re: Is it a linear progression between 90mm and 150mm?
Making this a LOT more complex than it needs to be.
IMO, better to not try making focal length equivalent between various formats be it film or digital. Better to work with what focal lengths deliver the in image object size and ratios within the image than trying all sorts of contortions to figure out what might be similar or not similar between imager formats..
It is the imager format ration you're working with at the moment that is important, what might be is not.
Moving the camera and it's position often works wonders to deal with focal lengths -vs- image composition for the given image ratio being used.
Bernice
Re: Is it a linear progression between 90mm and 150mm?
120 or 125mm is a perfectly fine focal length, if it suits you, but really the only way to know is to try it. When I started up with LF, I got a Tachihara 4x5 and a Schneider 120/5.6 APO-Symmar. I've since replaced that lens with a Fujinon W single-coated 125/5.6, which has a much larger image circle than the Schneider, and I've not had any flare problems with it.
120/121/125 isn't that popular of a focal length. There are several f/8 lenses that have huge coverage (280mm and up), more than you'd need for 4x5, that are better suited for 5x7 or larger formats.
For 4x5, the most reasonable options are the Schneider 120/5.6 APO-Symmar (or, better yet, the APO-Symmar L with its larger image circle if you can find one at a good price), or one of the many Fuji 125/5.6 options.
Here's the list of all Fuji lenses, note that they made some 120/8 and 125/8 wide angle lenses, as well as what may be up to 6 versions of the 125/5.6, of which mine is from either the first or second version: http://www.subclub.org/fujinon/byfl.htm
A quick check of ebay shows that the Fuji single-coated ones are in the $110-150 range, the EBC ones are in the $200-300 range, and any Schneider seems to be over $300, so if you're set on that focal length, look for a good condition Fujinon lens.
You may end up preferring 135mm or not even wanting something between your 90 and 150.
Re: Is it a linear progression between 90mm and 150mm?
In real world usage, and in terms of commonly available lenses, a 120 to 125 focal length would be the most obvious halfway house between 90 and 150. I can't think of any 110 except the very expensive Super Symmar XL, which is so close to the 90 as to be redundant unless you specially need the wider image circle. And at 115, there's just a big Grandagon. Most 105's barely cover 4x5, if at all, and are awfully close to the 90 perspective anyway. The Fuji 125W is a wonderfully lightweight lens without the distortions of wide-angle designs, if you don't need a lot of extra movements.
Re: Is it a linear progression between 90mm and 150mm?
Quote:
Originally Posted by
neil poulsen
Well, I'm back, and I thought about it. :)
For me, the multiplicative approach (above) works best. Every time I've increased the focal length by 1/3rd, I've "shaved" off close to 12.5% on each side of what I see on the ground glass. As a progression, I think that it makes sense to add or subtract a constant percentage of what one sees on the ground glass, each time one steps up, or steps down the progression of lenses. This is what a multiplicative progression accomplishes.
In fact, I like staying between about 25% and 33% in my progressions. That makes for more lenses; but, this enables me to "fill" the negative with a composition, once I've established a camera position. Thereby, one retains the advantage of a large format negative.
I love this post. Thank you Neil.
Re: Is it a linear progression between 90mm and 150mm?
Quote:
Originally Posted by
Drew Wiley
In real world usage, and in terms of commonly available lenses, a 120 to 125 focal length would be the most obvious halfway house between 90 and 150. I can't think of any 110 except the very expensive Super Symmar XL, which is so close to the 90 as to be redundant unless you specially need the wider image circle. And at 115, there's just a big Grandagon. Most 105's barely cover 4x5, if at all, and are awfully close to the 90 perspective anyway. The Fuji 125W is a wonderfully lightweight lens without the distortions of wide-angle designs, if you don't need a lot of extra movements.
This is another great post. Puts it all together.
Thanks all for the explanation.
Re: Is it a linear progression between 90mm and 150mm?
I used to carry a lot of lenses for the 4x5 format until I realised a well made 4x5 negative is very generous in maintaining image quality when cropped. I can crop a 90mm view out of what my 75mm lens takes in, 150mm view from the 135mm lens, 300mm view from the 210mm lens. The key thing is to put the camera in the right place for the composition required and then have a lens that at least "gets it all in".
Re: Is it a linear progression between 90mm and 150mm?
If you take a picture with a 90mm lens and crop it to the view from a 115mm lens you will be using ±77% of your film surface. It's the same for a picture cropped from a 115mm lens to the view from a 150mm lens. That makes a good reason to have a 115mm in a set 90mm-115mm-150mm. It is not a linear progression but a second order.