robert_deas3

<p>@Richard re prices, I am seeing genuine Hasselblad split prism screens really scratched and looking as though they were dragged behind a truck at $30, brand new Chinese ones $20-$50, and the Acute-Matte screens for ten times as much.</p>

<p>Yes it will give you more magnification. The further you move the lens from the camera, the higher the effective magnification when the image is focussed.<br>

<br /> The practical considerations as you take this to an extreme are <br /> 1) the image gets darker and darker<br /> 2) the depth of field becomes extremely shallow<br /> 3) it becomes very difficult indeed to keep everything motionless enough: the slightest environmental vibration will blur the subject, camera shake becomes really hard to avoid.</p>

<p>I had great fun experimenting with macro - here's something else you could try instead of lots of extension tubes: reverse a wide-angle lens. I rigged up a home-made mounting for a beautiful old Minolta Rokkor 24mm lens (that it was designed for use on a 35mm camera doesn't matter when it's reversed) mounted backwards on a Mamiya 645 body and it gave very high magnification and outstanding image quality.</p>

<p>I'm not concerned about brightness, I just want a split-prism. I can easily imagine that they could be made cheaply, it's just ground glass, none of the technical sophistication of the Acute-Matte and other bright screens.<br>

I would buy a Haselblad original, I just can't find one at a sensible price in good condition.<br>

I am aware of the Kiev stuff and use a couple of their prisms, as one poster mentions these seem perfectly matched to Hasselblad bodies. I can only see one Kiev split focussing screen for sale at present and it is the screen itself alone, without the metal frame with its four little feet that hold the screen at the right position. I'm perfectly happy to trust Soviet engineering, just not so sure about Chinese!</p>

<p>Hi, I am finding my original cross-hair focussing screen hard to use in critical situations but I haven't been able to find a genuine Hasselblad split screen in good condition that I can afford, and so I'm considering the Chinese-made copies on eBay at around £20.<br /> Obviously it's critical for focussing that the screen is mounted at exactly the right distance from the mirror, so the thing needs to be accurately made, and naturally this is something I am concerned about<br /> There are a couple of previous threads in which people have bought one and promised to report back (in 2010) but never did. Has anyone genuine experience of using them who can vouch for their accuracy of construction? They all appear to be from the same source, the photographs from all the sellers show the same box when it is included.</p>

Having lost my original charger that came with my 5D Mk II, I need to replace it but the Canon ones seem absurdly expensive. Has

anyone had any experience, good or bad, with 3rd party replacements?

<p>Thanks, Tommy, that was indeed a great link - it told me more than words could. I have to have one!</p>

<p>No, I can't shift it, no matter what I do. I can't use any more force or something will break. It's not oxidised onto the lens, there's some free play (there always was). It feels as though there is some kind of lock, but there is no button to press to release it, as there is on the camera body when you want to release a Mamiya bayonet and take a lens off. There is a tiny hole in the side of the adaptor at one point with a small silver screw visible in it - I wonder if this would somehow help me to dismantle it.<br>

<br /> I'll take some pictures and post them, I guess, in the hope that someone recognises the make of adaptor and knows the trick....</p>

<p>Thanks Omega, yes I read that with interest. The great thing about the many user reviews posted on some of the other lenses here, though, is that they give a vivid impression of how the lenses are in real daily use: a range of different people's personal views really builds up a good picture of how something is to use.<br>

I'm thinking seriously about buying a 5D MkII, having only used MF and LF film up to now, and am trying to make up my mind about lenses. The wider end is particularly difficult. I have the impression that a lot of people really find this lens exceptional, so it is a pity it hasn't attracted the same level of discussion and review as, say the 17-40mm f/4L which has a lot of interesting commentary and example shots.</p>

<p>Practically every other lens has numerous detailed opinions posted about it, but there are 0 reviews for this, which I would have thought would be a very widely used lens. I wonder why this is.</p>

<p>Thanks everyone. So it sounds as if it is just a matter of force. It feels so rigid I was afraid there was some catch or lock that I didn't know how to disengage, but if I'm sure there isn't I can try using more strength, or a wrench as suggested.</p>

<p>I don't think 67 is really realistic on that budget - but are you really going to be doing work where you notice the difference from 645? If not I'd strongly recommend an old manual Mamiya 645. They are very underpriced for the quality, many of the lenses are excellent. Before I moved on to Hasselblad and a 54 field camera I travelled for years with two old M645 bodies that proved totally reliable under all conditions. Used prices are very reasonable indeed - even the huge 30mm fisheye lens is affordable!</p>

<p>I have been using an old Zeiss Jena Flektogon on my Mamiya 645, using an adaptor which I bought some years ago. I have a problem with it, however: I cannot separate it from the lens again! Is there some cunning trick to this?</p>