72mm SA XL = 229mm
90mm f/5.6 SA = 235mm
... pretty close to the same coverage according to the manufacturer. Yes, these are different vintages/series but, IMHO, most folks are thinking of thinking of older series lenses. If we're discussing lenses of different FL's all with "enough" coverage then this post is valid.
As a previous poster stated, FL depends on positioning vs preferred amount, or the limiting of, distortion.
At one time the major pro photo schools would tell their students to buy a 4x5 along with
a 210 for portraits and 90 for architecture. This would cover most of the needs with a miniumum investment and give an image circle generous enough for movements. These were considered the "basics". Now it's a cell phone scavanged from the bottom of a Cracker Jacks box.
Price isn't the point, Leigh. It's about popularity of focal length for architectural photography. My argument is that until the 72 SA XL was on the scene the widest commonly available lenses that cover 4x5 with enough movement for architecture were 90mm. The 72 SA XL changed that. Price? If you're a professional you might pay for a good used one with one or two jobs. That would NOT be me, BTW.
The SA XL is a relatively new series of lenses, with much wider coverage than previous offerings from any maker.
This thread is talking about popularity. It takes time for any lens to build a reputation and a following.
Given the high price of the SA XL series, it's not likely to be warmly embraced by the majority of shooters.
They simply can't afford to try it, regardless of its performance.
If you believe you can, or you believe you can't... you're right.
A newer 90mm lens is a great workhorse for general architectural images (I have used a 90mm 6.8 Grandagon for a number of years) - with the abiltity for a lot of rise or fall for control of the perspective. Most architectural shots want to be a 2-point perspectives - that is to say the converging veritical lines are corrected to not converge by using the back of the camera parallel to the building facade. 90mm lenses also makes the building look bigger, and have more depth. 120mm and 135mm lenses are very useful as well especially on exterior whole building images. It does depend on what you are trying to show and intent of the image. Details are often shot with longer lenses - such as door handles and other smaller parts. For interior shots the 90mm lens is the starting point for me. I often use a 75mm Grandagon and have used a 58mm lens in the past for a really tight situation with a stairwell image. I have also had issues with where can I set a camera up and gain access to an image of a perticular building - some locations really suck - long lenses make a great difference. These images have been for commercial architectual images for my business as an architect.
I think anything wider than a 90mm on 4x5 falls into the category of, "The client wants the whole damn room in the picture and this is the only way to do it" versus taking a considered approach to describing the space by intelligently selecting what is significant via a longer lens.
It's like going to the Grand Canyon and popping on a super wide lens. Yeah you got it all in but you also emptied out most of the meaning.
I bet you rarely see many wider-than-90mm shots in the better portfolios.
And a $600-$800 90/4.5 Rodenstock Grandagon is an awesome lens with nice coverage but not as ridiculously clumsy as the Schneider XL lens.