Maxwell focussing screens

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rhodej00
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Maxwell focussing screens

Post by rhodej00 » Thu Jan 01, 2015 1:16 pm Etc/GMT-1+01:00

I would appreciate any comments on changing the Ebony screen for one of those available from Maxwell.
I use lenses from 72mm to 360mm focal lengths.
Are they worth the expense in terms of ease of focussing especially with wide angle optics?
John H Rhodes
http://www.johnhrhodes.co.uk
Scottish Photographers

George Hart
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Re: Maxwell focussing screens

Post by George Hart » Thu Jan 01, 2015 3:43 pm Etc/GMT-1+01:00

John, this is not an easy one because only you can make the decision after experiencing the difference, and without ordering one it's difficult to judge from another's experience. I have used the native Ebony screen with and without the Ebony fresnel, and also Beattie and Maxwell screens, though not all on the same camera. I would say that for similar equivalent "focal length" fresnels, ease of focusing is not much different between the different screens. If you go for a fresnel optimized for shorter lenses then focusing is less easy with longer lenses. So on my 5x4 I use the Ebony screen with their fresnel and it's excellent for 75 and even 55 mm lenses, but focusing the 240 in low-contrast conditions can be challenging.

For me the biggest advantage of fresnels is in optimizing the image quality rather than ease of focusing, and the 2 areas in which it can do this are field uniformity and overall brightness/contrast. In respect of the former, if you ask Bill for a non-wide angle fresnel then it should work well with the 72–360 spread, though you may have to move your head around a bit when using the 72 lens. If you ask for a wide-angle fresnel then you will be able to see the whole image with your head in 1 place with the 72 lens, but you may have to move your head around with the 360. As for brightness, the Maxwell screens are in my experience brighter than both the Beattie and the Ebony (even with their fresnel). But a couple of these have been too bright for my liking. I ditched the Maxwell in my Rollei TLR in favour of a Beattie because the light-dark contrast distribution made composition on this basis less good; everything was bright, nothing dark! I did the same more recently on my SW23, where the Maxwell screen was also too bright.

I have a Maxwell screen in my 5x7 Ebony and it is excellent, working for all focal lengths between 90 and 450 mm. I should think that the standard Maxwell for 5x4 (I take it that's what you are using?) will also work fine. Doubtless you will have the usual long chat with Bill who will give you his clear recommendation, but only you can say how it looks once it's installed.

Sorry to be long and a bit evasive, but I don't think this issue is straightforward, and it's certainly not cheap!

George

dave_whatever
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Re: Maxwell focussing screens

Post by dave_whatever » Thu Jan 01, 2015 8:29 pm Etc/GMT-1+01:00

I've also used the Ebony screen (which is a combined screen and fresnel), with and without the additional WA fresnel, and the Maxwell screen (can't remember the nomenclature but its the standard one). The Maxwell is brighter than the Ebony screen on its own, but the Ebony is still pretty good. They are probably equal in terms of suitability for a general range of focal lengths - moderate wide to moderate long. Personally I don't think the Maxwell is really better enough to be worth the cash, unless you're rolling in it. Expensive items like this tend to be self-fulfilling in terms of user feedback, as not many folk will spend top whack and then admit if its less than amazing. Hence you'll see a lot of user hyperbole about the Maxwell online, but very little honest feedback. I was lucky that I found one second hand, but still in retrospect it feels like an indulgence I could probably do without.

Now, for wide lenses this is where it gets interesting. The Ebony standard screen plus the WA fresnel is way brighter than the Maxwell into the corners of the screen for lenses wider than 90mm. Comparing them with my 65mm was like night and day. However once you get up to around 150mm the ebony combo becomes hard to use, with a distinct hotspot with longer lenses which gets worse with any rise or fall used. So the Ebony combo is great on wide angle cameras like the SW45 or RSW45, or on other cameras if you only want to shoot wides. Some folk talk about the Maxwell being magically amazing with all lenses from 47-500mm, but its just not the case.

For longer lenses I doubt there's much to pick between the stock Ebony screen and the Maxwell, though I never tested them and I no longer have the Ebony to compare with. Even a modern plain screen without fresnel seems fine for long lenses, so if you're mainly a long lens users, 210mm and up, I certainly wouldn't bother with a Maxwell.

One solution that some people go for is the Ebony screen + WA fresnel on one frame, then order a spare focussing frame to hold a spare screen for long lenses, and swap between them as required. The problem with this, apart from storing the spare screen in the field without breaking it, is mainly the exorbitant cost of a spare screen frame, about £500+ vat last time I looked - this makes a Maxwell as a compromise for all focal lengths seem a bargain. But then consider a spare focus frame for a Chamonix costs about $50

Now if you really want to be blinded when using wides then stick a WA ebony fresnel over the Maxwell screen - jesus christ, get your sunglasses out.

rhodej00
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Re: Maxwell focussing screens

Post by rhodej00 » Fri Jan 02, 2015 3:33 pm Etc/GMT-1+01:00

George I cannot locate the PM I sent you but have removed my Ebony screen and can tell you it consists of 2 items. A plain rear glass plus a front (lenside) glass with centre focus spot, grid lines and the asymmetric axes lines. So does an Ebony fresnel lens come as a separate item and would it replace the rear plain glass? This may be a better solution for me than an expensive Maxwell. John
John H Rhodes
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George Hart
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Re: Maxwell focussing screens

Post by George Hart » Fri Jan 02, 2015 5:16 pm Etc/GMT-1+01:00

John, the Ebony WA fresnel is indeed a third component which sits between the 2 that you have. However, it would not be any good for your longer lenses. I have it on my 45S (which I now use exclusively for MF) and my 240 mm lens is sometimes hard to focus with it, so anything longer would be worse.

The Maxwell screen replaces the gg component that you already have; you will still need the plain glass sheet behind. Maxwell does his screens with or without grid lines but I don't know whether he can do the asymmetric axis lines, so this could be a problem if you find them useful.

George

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