RB67 - Soft Focus Choices?

seall · Dec 11, 2018

Regarding the RB67 soft focus lens,

Can someone please enlighten me to any advantages there may be in using an Imagon adapted to the Mamiya RB67 system over the 150SF?

The Imagon's that I have come across on the auction site have what appeared to be a reasonably engineered adapter that fits between the RB67 and the Imagon itself.

Is the Imagon is the better choice between the two?

Also, Is it possible to use some of the same Imagon parts on 6x7 and 4x5?

Thanks in advance!

WilmarcoImaging · Dec 11, 2018

The Imagon in RB67 mount appears to be a 200m focal length, giving a flatter rendering than the 150. It is an aesthetic decision whether this is a good thing or not.

Alan Gales · Dec 12, 2018

There was a discussion about Rodenstock Imagons and Fuji SF lenses on the Large Format Photography Forum. I assumed they were the same since they both used "strainers". Someone said that in actuality they are a little different and give a little different look. Knowing this information, I would assume that the Imagon and the Mamiya 150 SF would also give at least a slightly different look. Plus, I would agree with the above post that longer lenses flatten a subject more too.

What you really need to do is try both lenses and see which you prefer.

As per Rodenstock, the 200mm Imagon is for formats up to 6x9. You will need the 250mm to have a large enough image circle for 4x5. Scroll down the link below to the Imagon pink chart.

http://www.prograf.ru/rodenstock/largeformat_en.html

Marco Gilardetti · Dec 14, 2018

Alan Gales said:
Someone said that in actuality they are a little different and give a little different look

I would rather say that they are completely different, the Imagon being a simple cemented doublet with all glass behind the shutter (it has no front lens), while Mamiya's SF is a triplet-derived lens with undercorrected spherical aberration.

Seall, I don't know if you have understood that in order to use the Imagon by means of the Zork Tubus on the RB67 you also need a shutter, as the Imagon comes without any shutter, so you have to "borrow one" from a Mamiya 180mm lens by unscrewing the front barrel.

Ian C · Dec 14, 2018

The 150/4 Mamiya SF owner’s manual:

http://www.reznitsky.info/Mamiya/Doc/RB67_150mm_Soft_Focus.pdf

Alan Gales · Dec 14, 2018

Marco Gilardetti said:
I would rather say that they are completely different, the Imagon being a simple cemented doublet with all glass behind the shutter (it has no front lens), while Mamiya's SF is a triplet-derived lens with undercorrected spherical aberration.

Seall, I don't know if you have understood that in order to use the Imagon by means of the Zork Tubus on the RB67 you also need a shutter, as the Imagon comes without any shutter, so you have to "borrow one" from a Mamiya 180mm lens by unscrewing the front barrel.

Marco, the quote you used from me was actually between the Rodenstock and Fuji lenses for 4x5. They are more alike than the Rodenstock and Mamiya lenses. I did say that I assume that the Rodenstock and Mamiya should at least give a slightly different look. How much different, I don't know. I've never tested them or remember seeing comparison photos.

You do bring up a very good point. The construction of the Imagon and the Mamiya SF lenses is quite different. They are similar in that they both use strainers. The Imagon in front of the lens and the Mamiya internally. This is a different design from the Wollensak Verito, Kodak Portrait, Cooke and other SF lenses.

seall · Dec 14, 2018

Marco Gilardetti said:
I would rather say that they are completely different, the Imagon being a simple cemented doublet with all glass behind the shutter (it has no front lens), while Mamiya's SF is a triplet-derived lens with undercorrected spherical aberration.

Seall, I don't know if you have understood that in order to use the Imagon by means of the Zork Tubus on the RB67 you also need a shutter, as the Imagon comes without any shutter, so you have to "borrow one" from a Mamiya 180mm lens by unscrewing the front barrel.

I have a 180mm C and understand what you are talking about as I have split the complete system before in order to clean it. It's an easy procedure.

Thanks for the answers and the link, all very interesting.

Think I shall have to spend some time reading and studying examples from the different systems and focal lengths before I look for either a MF or LF type.

Alan Gales · Dec 15, 2018

seall said:
I have a 180mm C and understand what you are talking about as I have split the complete system before in order to clean it. It's an easy procedure.

Thanks for the answers and the link, all very interesting.

Think I shall have to spend some time reading and studying examples from the different systems and focal lengths before I look for either a MF or LF type.

I used to own a regular (not SF) 180mm lens for my RZ67. I never needed to take it apart though. The SF Mamiya 180 and 150 lenses are designed to quickly and easily twist apart so you can put the desired strainer disc in. I have seen images on the web taken with these lenses and they can be really nice in the hands of someone experienced with them. I've read that with SF lenses you do need to focus on the tip of the nose to get the eyes in focus and that there is a little bit of a learning curve to get good with them. Of course practice helps with any lens.

Russ Young · Dec 15, 2018

I have the Mamiya 150SF-C, the Mamiya 180VSF, and an Imagon 200. They are nothing alike except for the pain-in-the-ass strainers. Whichever you get, be certain you have the entire set of strainers. The Imagon is considerably softer and has more flare than the Mamiyas. The Mamiyas are much "firmer", even w/o any strainer inserted and wide open. They have superb color rendition and maybe the best contrast of any soft focus lens I have used in any format. The 150mm is my favorite for landscapes and mroe distant subjects but seems too short in the studio especially for a head & shoulders shot. In situations where the subject is relatively close and the background distant, the bokeh of the 150 is "nervous" whereas the 180 is much smoother.
Russ

bushpig · Dec 22, 2018

seall said:
Regarding the RB67 soft focus lens

Are you the one who outbid me one the Imagon that just sold there? Or the one who snatched the 150mm SF 10 minutes after I submitted my offer?

In my mind it's the same person, watching my internet activities and snatching all the gear I want.

Alan Gales · Dec 24, 2018

bushpig said:
Are you the one who outbid me one the Imagon that just sold there? Or the one who snatched the 150mm SF 10 minutes after I submitted my offer?

In my mind it's the same person, watching my internet activities and snatching all the gear I want.

Hey, I know that guy! He's done the same to me over and over again!

RB67 - Soft Focus Choices?

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