View Camera Review Of Cooke Triple Convertible Lens

[mikewhi]

OK, status report time. I got a note from Clive today that my lens has shipped. I hope to have it this week. I asked for UPS 2-Day, so if he shipped it that way I'll it Wed or Thur! Copal #3 is standing by.....I'll post when it comes in.

A phot excursion sounds fine to me! I like that area, too, especially the drive west. If anyone knows good local spots, that would be good.


-Mike

 

[SchwinnParamount]

A phot excursion sounds fine to me! I like that area, too, especially the drive west. If anyone knows good local spots, that would be good.


-Mike

Mike, have you shot in the Port Townsend area? There are several late 19th century era shore battery installations plus the town itself is interesting.

 

[mikewhi]

I've been there a res times but I have never shot in the town itself. I was thinking more of areas 'nearby' like Hurricane Ridge or some waterfall areas if any.

-Mike

 

[JohnArs]

Hi

In my opinion a resolution and practical test would be much better, then only a practicall test because if a man or a woman falls in love with something then they get blind and that helps not for a real testing result!

 

[SchwinnParamount]

I've been there a res times but I have never shot in the town itself. I was thinking more of areas 'nearby' like Hurricane Ridge or some waterfall areas if any.

-Mike

Hurricane Ridge would be lovely! gotta make sure we go on a clear day though. I've ridden my bike up to the top from Sequim many times and sometimes it's been sunny in Sequim and foggyish (is that a word?) at the top. I guess checking the weather report that morning or calling the visitor center on the ridge that morning would be good idea

 

[mikewhi]

I got a call from UPS that my lens is in town! I got Serial No 29. If I get a spare $10k, I may bid on Serial No 1 when it comes up for auction<g>.I will go pick it up this evening.

I don't have a lens resolution chart. I did check them out once, but they are quite expensive. I got an e-mail from a member with a resolution chart that I could print out - but can an inkjet print out a res chart fine enough to test a lens?

Short of a chart, I can only do practical testing. Using front\rear, I get a focal length of 311 and rear alone I get 476mm (front alone gives 646mm!). I have modern lenses near these focal length that I can compare the Cooke to, if that would mean anything to anyone. The only vintage lenses I have are a 19" Red Dot Artar and a 240mm Zeiss Dagor (the rare one, which I believe is f9??). I also have the Wisner 5x7 convertible set, but I'd expect the Cooke to blow it away. I have many Schneider, Fuji and Nikkor-W lenses. I will defenitely compare the Cooke to the Nikkor-W 360, the sharpest and brightest lens I have now. I do have a 480mm Schneider Symmar-S, too. I also have a 305 G-Claron that I'll compare the the front\rear combination.

Any opinions about the validity of these comparisons? Is lens design such a huge factor that comparing a G-Claron to the Cooke at 311mm would be meaningless? Even so, I can at least comment on general image characteristics of each, I suppose.

If anyone has any specific questions that won't take a lab or professional lens tester to answer, let me know. You know, questions somewhere between 'is it pretty' to 'what is the refractive index of the langham glass elsements'.

-Mike

 

[Ian Grant]

Gordon Hutchins is a very knowledgeable long time LF practitioner and if I was going to take somebody's word, he would be one. OTOH, like you say, perhaps not to the tune of $2500 dollars.

This actually raises a very serious issue.

For once the UK / US price reflects the exchange rates, Normally we in the UK, and the rest of Europe's prices are similar, pay the same price in Sterling as the US do in Dollars. So a camera in the UK at £200 is on sale for $200 in the US, and this is typical of other products as well. This is despite the exchange rate being heavily in our favour.

Far East manufacturers sell volume at break even in the US, many say dump, and make their profits in the European and other markets.

Of course a UK company like Cooke who's lenses are very specialist and at the higher end of market prices in the UK, will be very expensive in the US while the $ is so weak.

 

[WarEaglemtn]

"I have modern lenses near these focal length that I can compare the Cooke to, if that would mean anything to anyone."

I think this would be a good way to go. If possible, photograph the same thing with both lenses & process the two sheets identically to see if anything shows on the negative as a visual difference in them as well as with the contact prints. Comparing to what you know is an excellent performer will give us some useful information.

 

[jd callow]

I don't have a lens resolution chart. I did check them out once, but they are quite expensive. I got an e-mail from a member with a resolution chart that I could print out - but can an inkjet print out a res chart fine enough to test a lens?
-Mike

Use dollar bills or even a combination of news papers (photo images are @ 85 lpi) and magazines (133-150 lpi). they won't give you measurements you can compare to a chart but it will give you a good idea.

 

[Oren Grad]

Any opinions about the validity of these comparisons? Is lens design such a huge factor that comparing a G-Claron to the Cooke at 311mm would be meaningless? Even so, I can at least comment on general image characteristics of each, I suppose.

Mike -

I'd be very interested in a comparison between the Cooke at 311 and the 305 G-Claron, since I'm quite familiar with the "look" of the G-Claron family. I'm especially curious about how out-of-focus backgrounds look when rendered by the Cooke. I'm most interested in its behavior with subjects at midrange that fall gradually out of focus (for example, a picture taken at a middling aperture from inside a stand of trees), somewhat less in what happens with a close subject with background at infinity.

Congratulations on your new toy, and have fun!

 

[Oren Grad]

Mike -

I see on reading your message again that you have Fuji and Nikkor-W glass on hand as well. Any comparisons of image character with those, if the focal lengths aren't wildly different, would be of interest as well.

 

[Tom Stanworth]

Yeah come one you hoity toity 'too posh to post' owners of the fabulous new Cooke convertible! You have had them for ages now and are clearly denying us the comparison test to tease us. I think you should be thown off APUG and confined to your yachts

I dont especially care about resolution tests. The same subject would be fine at the same approx focal length at working apertures. It would give a good idea of apparent resolution and contrast. A wood from a moderate distance would provide lots of sharp twigs and leaves to show up differences if there are any.

I note there was mention of the look of the G clarons, how would you describe this? I have recently acquired the 150 (on the way) 210, 240 and 305 tho have not had a chance to shoot them at all let along extensively to look for a family trait. (I've only done some early test negs with my 300 geronar and wolly 159 12.5)

Tks,

Tom

 

[WarEaglemtn]

How long have they been out now? Long enough for someone who bought one to actually have used it in the field? If so, why no posting as to results?

 

[mikewhi]

OK, I just got back from UPS with the package with the lens in it. I really want to open it, but I really have to go to the bathroom, too. Which one should I do first? If you're reading this, I'm sure you understand that it isn't an easy choice.

You can start turning green with envy. I'm turning green for another reason.

Back to you soon.

Anyone want to see thumbnails of the lens? Clive Russ has nice pic's of it on his site.

-Mike

 

[Mongo]

I really want to open it, but I really have to go to the bathroom, too. Which one should I do first?

Apparently "Post a note on APUG" won out!

 

[HenceForthWith]

How long have they been out now? Long enough for someone who bought one to actually have used it in the field? If so, why no posting as to results?

Feel free to purchase one and post the results.

 

[mikewhi]

Apparently "Post a note on APUG" won out!

Yes, there are some things even I can't resist.....

Initial impressions:

1) I bought the one without the shutter as I have some Copal #3's at home.

2) There are tools required for installation. You have to remove some stuff from the shutter that needs really tiny screwdrivers to install the f-stop scale plate\ring and then re-assemble the shutter.

3) Unfortunately, I can't just screw the front and rear elements on and go shoot. Not wanting to screw this up, I'm taking my time. They even give some grease in a syringe with instructions on greasing stuff up and spraying something with WD-40.

4) The coating is quite nice as reputed. When held at an angle, it shows the familiar magenta and green reflections of the coating materials. The glass is excellent. Just looking thru it you see no glass at all. When I look at some printed material on white paper thru the lens and then without the lens, there is barely any loss of light - the printing looks almost identical both ways.
This is also true of my Nikkor-W's, though. I don't visually see a lot of difference in the brilliance of the images thru the lenses.

5) The lack of mfgr. supplied internal lens caps seems odd for such a high-end item. I will buy the ones from S.K. Grimes - they are certainly going to be needed in the field. I don't consider them optional items at all. Fumbling around on some rocks on a windy day and oops, there goes $1200. I would even like to have had a mfgr. supplied box like my Wisner 5x7 Plasmat set has. Nice felt-lined compartments to keep everything safe. I guess lens wraps will have to do until I can find something better. Do any current owners carry the lens in anything that works well in the field??

6) The supplied lens caps are nice - solid metal with the Cooke brand name on the outside. No cheesy plastic here. They provide a liner on the inside of the cap that gives a good snug fit. These won't be falling off in the field.

7) The phsysical dimensions of the lens are not imposing at all. It is pretty lightweight. The diameter of the glass surface on the front element is about 1 7/8th inches. As compared to over 3 inches for my Nikkor-W 360. It is quite light, too. This lens, in combination with my Dagor\Carl Zeiss Jena f:9 240mm will give me 4 focal lengths for 8x10 in a small package. 2 lenses, 1 lensboard, one shutter and 4 focal lengths of 240mm, 311mm, 476mm and 646mm. My Dagor is in barrell and screws directly into the front of the shutter - some vignetting but not too much. It will be easy to pack this setup around in my f64 backpack. I'll even be able to leave one or both side pouches behind and and still have room for lunch.

8) Just looking at the lens, I am certain that with both elements in place it will hold it's own against anything I have. I have been told by Clive Russ that the 'bokeh' is different (and in his opinion more pleasing) than the razor-sharp approach of the Nikkor-W lenses. I don't know if this is an attempt to 'romantacize' some image degradation, but I really doubit it after seeing the lens. I will be very interested in the performance of the individual elements - I have been told that they are quite good on their own. We shall see.

9) Got the scale out.... rear element weighs 226 grams with the lens cap on.
Front element weighs 343.5 grams. Lensboard and shutter, priceless. I mean, they weigh 567 grams. So, 2 lenses, 1 board, 1 suttter in total is 1167.5 grams or a little over 2.5lbs. Not bad.

10) With both elements at 311mm this is a f6.8 lens. Nice. We'll see how it shoots wide-open. Rear element alone at 476mm, speed is f\11. Front element alone at 646mm it is f\16.

My overall impressions are that it is a beauitful and very well made lens. I'm glad they sell it without shutter and they send you everything you need to install the shutter yourself. The instructions are pretty clear, in spite of being written in British. Nice exploded diagrams that make it look like there are a zillion parts when there are bsically 3 or 4 to deal with. It is packaged EXTREMELY well. Lots of solid foam and double-boxed. Very nice.

I am no lens expert, these are just my impressions. I will do some testing and comparisions with modern and classic lenses and post my impressions and scans (for whatever that will be worth). I guess I can e-mail higher res scans to those interested. But I have only a basic scanner, nothing fancy. I'll put negatives on a lightbox and look at them thru a 10x loupe, too for those branches against the sky stuff.

If you have any special requests for testing, let me know and I'll try to accomodate them if I can. I plan on shooting Plus-X developed in Rodinal. Let me know if you have better ideas. I have FP4, EFKE 100, EFKE 25, J&C Classic, Pro, etc. I don't have a lot of developers and I don't plan on mixing any up so forget me wasting perfectly good Starbucks coffee to make a developer. I will shoot 4x5 and enlarge them as much as I can. I don't see a lot of value in 8x10 contact prints to comapre lenses - I mean, is there any chance this lens would not make great 8x10 contacts in any configuration?

Take care.

-Mike

-Mike

 

[WarEaglemtn]

"Feel free to purchase one and post the results"

HenceForthWith... you are a Ass.

 

[mikewhi]

OK, I got the lens assembled. I printed out a lens resolution chart to examine. It's night and I can't take the camera out, but I atleast wanted to try something and this is better than nothing. I printed out this chart:

http://www.graphics.cornell.edu/~we.../res-chart.html

I can honestly say I am amazed with the lens. I examined the chart in all 3 focal lengths and I could see lines resolved down to the smallest size in the bands marked '10'. Even in single cell configurations. And this was wide open! The images were bright, clear, contrasty, amazingly sharp. So far the only other lens I put on is a Schneider Symmar-s 480mm - a huge lens with an enormous front element. The Cooke was easily as good as this lens, again even in single cell configurations.

This work is preliminary. I just put the chart up on the wall, lit it well and studied the projected image with a 10x loupe. I didn't take precise care to ge sure the projected image of the chart was exactly the same with each lens - I'll do that next. I just wanted initial impressions to see if there were any glaring differences.

I will be more precise with my testing next and I'll compare to a wider variety of lenses including Nikkow-W, Fuji, G-Claron, and an Red Dot Artar and a Zeiss Dagor 240mm f\9.

If I had any doubts amoubt recommending this lens, they are beginning to fade. More tests and actual photographs will tell the story for me.

-Mike

 

[Mongo]

I printed out this chart:

http://www.graphics.cornell.edu/~we.../res-chart.html
-Mike

The link in Mike's message is broken. The full address is:
www.graphics.cornell.edu/~westin/misc/res-chart.html

(You'll need to install the Adobe SVG view to see it. You can get that at www.adobe.com/svg/viewer/install/main.html)

The address of a PDF version of this file is:
www.graphics.cornell.edu/~westin/misc/ISO_12233-reschart.pdf

 

[mikewhi]

Thanks, Mongo, although I was able to get there with the link I posted....don't know why.

I printed it off on a standard HP inkjet printer. If everyone looks at, we can establish a common reference point to discuss the lenses. I can refer to specific sections of the chart and we'll all know what we're talking about.

I have a bunch of Type 52 4x5 Polaroid film coming in next week. Do you think pictures of the chars on this fill would be useful? It would save a lto of time in developing and printing from Plus-X negatives.

Take care.

-Mike

 

[Mongo]

Mike-

Thank YOU for posting the link. Although it didn't work for me (and I don't know why that would be), I'm glad to finally have access to a resolution chart that I can print. I'll be preparing a chart this week for some testing that I have to do with a bunch of lenses I own...this is a project I've wanted to do for a while but I didn't know where I could get the chart.

My primary interest is to test a hypothesis that I've had for a while. I think (although I have no proof of this) that every lens I own will have similar resolution at the real-world apertures I use. (I own everthing from modern multi-coated wonder-lenses back to old, uncoated glass...I think the differences are in flare resistance and image circle, not resolving power.) Specifically, I rarely shoot at anything larger than f/32. F/22 on very rare occasion. I intend to print out the target and shoot every lens I own at both f/22 and f/32 to see if there is any difference in their resolving power. My own observation of the negatives that I've printed over the years leads me to believe that the diffraction of the lens is the limiting factor, not the glass itself. I'll finally be able to prove to myself scientifically if I'm right or wrong.

Again, thank you for providing the link to the test chart. I'll be interested to see the results that you get. Perhaps somewhere in here is a chance for a bunch of APUG'ers to set up a standardized test to compare lens resolution...

Be well.
Dave

 

[mikewhi]

I finally got some time to post a few comparison photographs in my personal gallery.
I shot some dried sunflower close-ups with the XVa and also a Schneider G-Claron 305mm. This particular picture from the XVa was taken with both elements in place, a focal length of 311mm. Both were shot at f\64 for 4 sec using Polaroid Type 52 4x5 film at ASA 400.

You can view the images and make what you will of them. For my eye, the XVa has more accutance and resolution. I examined each image on the ground glass with a 10x Peak magnifier wide open. The Cooke image was superior in my opinion. It certainly seemed sharper and more contrasty. The detail in the bright leaves of the sunflower were more apparent with the Cooke.

One thing that I did notice with the Cooke was that when I focused wide-open and slowly stopped down, the image became noticeable less sharp before f32. I could re-focus and improve the image slightly at that point. This will bear further investigation and experimentation. I have heard of a focus shift with convertible lenses, but I don't know if this occurs with both elements or only in single element configuraiton. I only worked with the 311mm configuration tonight. I didn't have enough bellows draw to shoot with the 476mm or 646mm close-up.

Personally, I am very pleased with the Cooke's performance tonight. I think it took some excellent close-up images. I can't help that we're limited in the size of the image we can upload. If someone wants me to e-mail them a higher-res scan, let me know. If there aren't too many requests, I'll sent the Cooke images along.

mikewhi@comcast.net

-Mike Whiting

 

[David A. Goldfarb]

Thanks for posting your results. I think it's going to be hard to tell much about the resolution of the lens using Polaroid or f:64, and a lens is going to perform differently at a magnification of 1:1 than it will for landscapes, but it does look like the Cooke has better contrast (presuming the light didn't change between the two exposures) than the G-Claron.

Usually the focus shift problem with convertible lenses occurs with the single cells because it's not ideal to have the stop in front of the lens (though it's usually better in front than in back). If you're seeing focus shift with both cells in place, I'm wondering if they've found a way to split the difference (perhaps by making both cells slight telephotos), allowing some focus shift with both cells in place in order to reduce focus shift with the single cells.

 

[WarEaglemtn]

It has been awhile. Any new results on the comparison testing? I hope the silence across all the LF discussion boards on the lens aren't a bad omen.