View Full Version : Cooke triple convertible vs. other lenses

18-Nov-2006, 09:49
I have recently ordered a Fujinon 600 to complete my range of 8x10 lenses but, after reading accidentaly an article by Gordon Hutchinngs about the Cooke Triple Convertible, I was considering the possibility of selling the Fujinon 450 and the Schneider G-Claron 305 I own and buy the Cooke Triple Convertible.

The Cooke will cover roughly the three focal lenghts (305 - 450 - 600 mm) with the combination of the two cells (311 - 476 - 646 mm), plus it will have the advantage of using a single shutter (over three of them) and therefore allowing a much better consistancy in terms of shutters times.

In terms of optical results, handing in the field and overall money value, can this be considered a good move ?

Herb Cunningham
18-Nov-2006, 10:18
I use mine unless I need a shorter lens than 300.

It is very good optically -Gordon Hutchins was very positive about it at a seminar this year.

They are expensive, but kinda like a piano, you only need one.

Eric Leppanen
18-Nov-2006, 11:28
I owned a Cooke XVa for about six months, which I ultimately sold because I don't hike much with 8x10, and tend to prefer conventional lenses for use near the car. Here is a summary of my experience:

- While the Cooke does not save much weight versus, say, a Fuji C 300/450/600mm lens set, it saves quite a bit of bulk and takes significantly less space in the backpack.
- Superb lens coating and few internal elements make for superb flare resistance, the best I've ever seen in these focal lengths. Flare artifacts are a subdued green, rather than a bright red as with many lenses.
- Superb contrast.
- The lens reportedly has excellent bokeh. I am not much of a bokeh person so I couldn't comment on this one way or the other.
- I did not notice any focus shift with any of the focal lengths.
- While the 311mm focal length does not have a particularly large rated image circle, its much larger circle of illumination loses sharpness gradually and has a nice, ethereal look to it (I once exceeded the rated image circle by using a lot of front tilt, and the clouds at the top of the image had a soft, creamy quality which was actually quite appealing).

- Single cell configurations (476 and 646mm focal lengths) require far more bellows extension than conventional lenses. Not only does this require a larger and heavier camera (you'll need 900mm+ of extension if you want to focus the 646mm focal length fairly closely), it makes the camera more vulnerable to wind and vibration in the field. You'll also find yourself using mostly rear movements with the 646mm since the front standard is hard to reach while looking through the ground glass. This is the lens' biggest drawback IMHO. As a practical matter, I generally got slightly sharper pictures in the field with conventional lenses than the Cooke single cells (even when using a long lens support arm to stabilize the front standard).
- For relatively close-up subjects (say roughly 5m distant or closer), I got sharper results with a plasmat than the 476mm Cooke when evaluating chromes with a 10x loupe. Cooke says the 476mm focal length is optimized for a 7m subject distance. My 600mm APO Tele Xenar also outperformed the Cooke 646mm close-up, which surprised me since the Tele Xenar is optimized for distant objects. Comparing the Cooke to the Fuji C 450 and 600 close-up, I would say the Fuji 450C is slightly sharper, and the 600C roughly equivalent. However, if you don't make big enlargements then none of these sharpness differences will likely matter.

In summary (from the perspective of an outdoor photographer, I don't do indoor studio work), I would say the Cooke is best-in-class as a compact field optic for photographers hiking with their 8x10 field kit, and where the 646mm focal length is used for distant subjects only (keeps extension and stability requirements down). The 311mm focal length matched my much larger 300mm APO Sironar S in any test situation I created aside from rated coverage (and had better flare characteristics). The single-cell 476mm and 646mm focal lengths incur a few design trade-offs, which is not at all unreasonable considering the compactness of the design. If you do decide to purchase the Cooke, I strongly suggest getting at least one of the SK Grimes supplemental lens caps designed specifically for the XVa, which will protect the unused lens element when shooting with a single cell.

C. D. Keth
18-Nov-2006, 11:48
In terms of optical results, handing in the field and overall money value, can this be considered a good move ?

Sounds like a darn good idea to me. Don't forget that a convertible is also lighter and more compact than 3 different lenses, too. Two fewer shutters and boards will make a significant difference in weight and packing volume.

I like the look of the cooke convertibles very much and if you do, too, it would be a great idea IMO.

18-Nov-2006, 13:59
Thanks a lot to all of you.

Ciao from Italy

Gary Smith
18-Nov-2006, 17:18

My experience with the lens is very limited, just got it about a week ago. But I will share my initial impressions.

Wide open its sharper than anything else I have used on 8x10. At 311mm, I compared it to both a Fujinon 300C and a Fujinon 300CMW. Wide open the Cooke is the winner. And at least on the ground glass holds the lead or is every bit equal for me until about f/45. From then the 300CMW is sharper, but since I rarely go below f/45 its not much of an issue.

At 476mm, I compared the Cooke to a Nikon 450mm F/9 M. The Nikon is a very very sharp lens. The Cooke seems to be about the same again until f/45 the diffracation probably kicks in the Nikon is sharper using a loupe. Since I am doing contact printing I doubt the difference will even be noticable.

At 600mm, I compared the Cooke to a friends 600mm Fujinon C. The big disadvantage of the Cooke at this focal length is the bellows needed. Instead of 600mm extenstion with the Fujinon, the Cooke takes a little over 700mm. THe image quality was a draw to me, futher testing might reveal a difference but it was very close.

I have only shot a few sheet of film with the lens so far, and so far I am very very pleased. The lens image quality on paper is every bit as good as the Fujis and Nikon the lens replaced. The Cooke seems to have slighly more presence (very subjective I know), and alot less flare.

I will need to use the lens more before I make a final determination, but it seems like a heck of a winner to me.

Hope it helps.


Bruce Schultz
19-Nov-2006, 07:42
If you want to sell the 450 fuji, let me know please.