Which 90mm lens has the shortest rear element?

[Mick Fagan]

Mine covers 4x5 with a small amount of shift spare.

With the rear lens cap off it sticks out about 5mm with the lens cap on about 7mm.

I don't think you will get much a smaller rear intrusion than that.

Mick.

[jnanian]

a 3 1/2" wollensak exwa f12 has a large circle
when stopped down it will cover a 5x7 sheet
and it is tiny, like an angulon.
a 90mm raptar (OPTAR) as well
( and i think one is for sale in the classyfieds ) ...
i had both lenses and used them often.
lots of coverage / image circle ...

[kirkfry]

A 90mm/6.8 Angulon will cover 5X7 stopped down. See http://www.bruraholo.no/Cameras/Angulon/index.html
Mine which is a late model ~1960 is very sharp. The back element is flat with the shutter. K

[2F/2F]

Perhaps it would help if you told us what you are doing that is moving your plane of focus so far behind the ground glass, and that also requires 5x7 coverage. No one will shoot you for mentioning your plan, even if it involves digital. We just don't want to hear a bunch of effing questions and answers about the digital part of it.

The 90mm Wolly in the classifieds is spoken for by me. I did not plan on it providing any movements even on 4x5, and am surprised to hear that it will cover 5x7 stopped down. Everything I have found about it mentions how soft it is and how it allows almost no movement. I am hoping that John's description is closer to the truth!

[Icescapes]

Thanks guys.

As to the digital application 2f/2f, I've modified a mount with an EOS bayonet in the center that I attach to the rear standard. This allows me to do up to 9 rows of 9 shots through rise and fall and shifting. I later stitch together in PS3.

The problem that this setup has (other than not having grain) is that the Canon camera's sensor is recessed about 35mm or so into its body. Once you add another 10mm to clear the hand grip and some wasted space between that and the filmback mount surface, you've used up the focal length of a wide-angle lens for 4x5 coverage by positioning the film plane all those millimeters behind the rear standard.

The mods that will help this are 1) sand about 2mm off the hand grip, 2) reduce the bayonet extension tube by about 7mm, and 3) use a thinner piece of aluminum by about 1mm for the filmback mount.

These mods will allow me to barely focus a 75mm lens at infinity (currently can only focus at about 1 foot with it), but will allow me to focus a 90mm at infinity and have room for shift/fall/rise movements on the rear standard (provided that the rear element isn't long as mentioned through this thread).

Pete.

[2F/2F]

Thanks guys.

As to the digital application 2f/2f, I've modified a mount with an EOS bayonet in the center that I attach to the rear standard. This allows me to do up to 9 rows of 9 shots through rise and fall and shifting. I later stitch together in PS3.

The problem that this setup has (other than not having grain) is that the Canon camera's sensor is recessed about 35mm or so into its body. Once you add another 10mm to clear the hand grip and some wasted space between that and the filmback mount surface, you've used up the focal length of a wide-angle lens for 4x5 coverage by positioning the film plane all those millimeters behind the rear standard.

The mods that will help this are 1) sand about 2mm off the hand grip, 2) reduce the bayonet extension tube by about 7mm, and 3) use a thinner piece of aluminum by about 1mm for the filmback mount.

These mods will allow me to barely focus a 75mm lens at infinity (currently can only focus at about 1 foot with it), but will allow me to focus a 90mm at infinity and have room for shift/fall/rise movements on the rear standard (provided that the rear element isn't long as mentioned through this thread).

Pete.

Hi, Pete.

That is exactly what I assumed you were doing.

If everything is aligned perfectly, you can get one heck of a file with this method. Drawback, of course, is still life work only, and the aforementioned hassle of making sure everything is perfectly square before shifting.

How far can you shift the camera before the image is clipped by the shadow of the lens mount?

My next question would be: Why do you want such a wide angle of view? Do you need it for still life work?

Sounds like a custom camera is the key here. You need something that completely eliminates the rear carrier frame. Not hard to rig, actually. You just need to engineer a way to squarely mount the SLR to the rear standard (modified L bracket), and a way to seal the bellows to the EOS lens mount (AKA lots of gaffer tape).

[Ole]

A 90mm/6.8 Angulon will cover 5X7 stopped down. See http://www.bruraholo.no/Cameras/Angulon/index.html
Mine which is a late model ~1960 is very sharp. The back element is flat with the shutter. K

... depending on the age of the lens and your definition of "coverage". As my little test shows, later ones are sharper within the intended coverage but fall off more rapidly outside that radius. Older ones have a more gradual loss of definition beginning earlier, which leads to the curious result that the corners on 5x7" are actually sharper than with a newer lens - which however gives sharper corners on 4x5".

[Icescapes]

Hi, Pete.

That is exactly what I assumed you were doing.

If everything is aligned perfectly, you can get one heck of a file with this method. Drawback, of course, is still life work only, and the aforementioned hassle of making sure everything is perfectly square before shifting.

How far can you shift the camera before the image is clipped by the shadow of the lens mount?

My next question would be: Why do you want such a wide angle of view? Do you need it for still life work?

Sounds like a custom camera is the key here. You need something that completely eliminates the rear carrier frame. Not hard to rig, actually. You just need to engineer a way to squarely mount the SLR to the rear standard (modified L bracket), and a way to seal the bellows to the EOS lens mount (AKA lots of gaffer tape).

I actually did a custom fit to a Horseman LE, and it worked great...down to 120mm. I still use the groundglass for composition, then i put in the modified plate to hook up the EOS, so I still want the carrier (I've seen the SLR L-bracket mount before, and though a good solution that I've contemplated, I don't want to have to dismount the carrier, and mount the L-bracket everytime after composing). This time around, though, I'm confident that I can reduce enough wasted space between the mount and the standard to get to 90mm with comfortable movements. A little bit of work myself, and a little bit of machine shop work will get me there.

As for why I want to work with wide-angle glass like 90mm, I like the field of view it gives for landscapes.

Haven't had any shadow clipping caused by the lens mount, I can go to the edge of the image circle of both my 120mmm and 150mm Fujinons comfortably. What shows up on 4x5 groundglass is pretty close to the resulting stitched image.

[David A. Goldfarb]

I wouldn't use a 90mm/6.8 Angulon for a format larger than 4x5", unless you want the soft edges as an effect. It illuminates a large circle, but definition drops off rather drastically.

[Ole]

I agree David, but the degree of "drops off rather drastically" depends on the age of the lens. A pre-WWII one can be stretched to cover quite a lot, although you have to sacrifice overall sharpness by shooting at f:45!