Hasselblad HCD 28mm f/4

[rdeloe]

Does the Hasselblad HCD 28mm f/4 use a floating lens optical design? Alas, it's not apparent to me from the lens block diagram in Hasselblad's technical data sheet.

 

[FloatingLens]

I've got that lens in front of me here. Not conclusive, the rear lens element moves upon focussing.

 

[rdeloe]

I've got that lens in front of me here. Not conclusive, the rear lens element moves upon focussing.

Thanks for the quick response!

When you say the rear lens element moves upon focusing, are you doing that off camera? In other words, can you focus an H lens off camera, or is it entirely electronic and controlled from the body?*

* Questions asked in near-total ignorance of the H system! Thanks for your patience.

 

[FloatingLens]

No worries Yes, off camera. And yes, it's a classic AF lens with gears, so the lens doesn't need to be powered.

What can also be said is that the lens does not extend nor does the front rotate. It has a fixed length.

 

[rdeloe]

I would love to have a really good 28mm lens for my outfit, and this one is literally the "last man standing" in terms of what I could possibly use. If I knew it was unit focusing, those cells would be out of that housing and in a new mount in a flash.

Unfortunately, if it's a floating element design, it has to stay in its helical, and I doubt I'll be able to jury rig a mount with an aperture I can control. From what you're saying, and in light of its performance, I'm guessing it's a floating element design.

Oh well, so it goes. Thanks for helping out.

 

[TechTalk]

Rear focusing means that only the rear group of lens elements move during focusing. Sometimes this is abbreviated as RF.

A floating element or group of elements is in addition to and separate from the primary lens focusing elements and used to improve performance for close focusing distances. Nikon calls this "Close-Range Correction (CRC)".

https://imaging.nikon.com/lens/glossary.htm#rf

https://www.lensrentals.com/blog/things-you-should-know-about-your-lenses-but-may-not/2

According to their lens data sheets, the only current (H or X series) Hasselblad lenses which incorporate floating elements are the XCD 30 mm (Full focusing with floating mechanism) and XCD 120mm Macro (Internal focusing with floating mechanism). Hasselblad provides users very detailed information on their full line of lenses.

The Hasselblad HCD 28 mm data sheet describes it as rear focusing without mention of floating elements. As you know, it's a great performer.

https://cdn.hasselblad.com/x-h-system-lenses-v3.pdf

 

[rdeloe]

Rear focusing means that only the rear group of lens elements move during focusing. Sometimes this is abbreviated as RF.

A floating element or group of elements is in addition to and separate from the primary lens focusing elements and used to improve performance for close focusing distances. Nikon calls this "Close-Range Correction (CRC)".

https://imaging.nikon.com/lens/glossary.htm#rf

https://www.lensrentals.com/blog/things-you-should-know-about-your-lenses-but-may-not/2

According to their lens data sheets, the only current (H or X series) Hasselblad lenses which incorporate floating elements are the XCD 30 mm (Full focusing with floating mechanism) and XCD 120mm Macro (Internal focusing with floating mechanism). Hasselblad provides users very detailed information on their full line of lenses.

The Hasselblad HCD 28 mm data sheet describes it as rear focusing without mention of floating elements. As you know, it's a great performer.

https://cdn.hasselblad.com/x-h-system-lenses-v3.pdf

That's extremely helpful. Thanks you.

Unit focusing lenses are very easy to adapt for my setup because I prefer to focus by rail. Most of my lenses work that way. An RF lens would have to stay in its helical, which makes things more complicated. Definitely not impossible, but more complicated.

One of these days someone will put a dead HCD 28/4 up for sale that has good optics and I might just take a chance to see for myself if this could work.

 

[TechTalk]

I've been enjoying all of the information you've provided on optics. I'm glad that I could provide something useful to you in return.

I thought that unit focusing (Full focusing using Hasselblad nomenclature) was likely what you wanted. Patience is always a virtue when doing this kind of hunting. So, I wish you luck in your hunt!