Rear format reducing converter

[bakubo]

I have this vague memory of someone selling something maybe a couple of years ago. Maybe it was something like a special tripod head for shooting panoramas or something like that. I think I read a post from the guy who was selling it (and who had designed it) that he had somehow made arrangements with someone in China to produce it. My recollection is that it was something that was sort of "advertised" on a forum someplace. My memory is so fuzzy about what it was and when that it may just be some sort of daydream I had once.

[Greg Beetham]

Also, without an exact schematic layout with specifications and measurements and maybe no existing unit to copy either, means you would be in R&D territory, ie. this is what we want to do, can you come up with something to accomplish this...? that my friends, could be fraught with peril.
And then there is unit cost, I don't know what the prototype would cost but the finished item would most likely have a cost based on how many you would be willing too order....
Greg

[bakubo]

Also, without an exact schematic layout with specifications and measurements and maybe no existing unit to copy either, means you would be in R&D territory, ie. this is what we want to do, can you come up with something to accomplish this...? that my friends, could be fraught with peril.
And then there is unit cost, I don't know what the prototype would cost but the finished item would most likely have a cost based on how many you would be willing too order....

Yes, you are right. That is why, I presume, no one on this forum is a successful entrepreneur and making big money. See all the problems and then give up.

[Greg Beetham]

Yeppity yep, and you know what else Henry, and I might even be willing to lay a couple of light ones on it, (not heavies), that for every successful entrepreneur there is probably half a dozen bankrupt ones.
Greg

[Javelin]

I've already done the design for an adaptor to fit the hotshoe on Sony for a guy who messaged me from DPR. he has a product that will mount on an articulating arm that attaches to hotshoes on any camera, should be out shortly actually and Sny was going to be a proble... it was a simple device but I sent him the solid model and drawings about a month ago for free. Since then he's not answered any of my mail (haha I dunno what hes thinking I didn't really want to be involved or make any demands) but I still get the updates he sends his "team" the last thing looked like the artwork for the packaging and brochures. I'm not sure how he was manufacturing but he spent big bucks on the tooling for the cabinet his product goes in and it wouldn't be cheap for the adaptor I made for him because I speced out a special kind of plastic so it could be very small.

This sort of thing happens every day. most times it's little devices like this or a certain peice of hardware or knob, clip or a hinge. The easiest thing is to send a sample of what you want after you've found a manufacturer But Greg is right. going there with only an idea and expecting them to be able to prototype it for you is going to get you into trouble and may never get you what you want. They rarely fully understand what it is they are making and sometimes they make a decision to save costs not realising how that can effect whatever it is. If your only making 100 pieces then it's not worth going there for it just get it made locally whatever it is.

[Javelin]

Ahh but the point to take home is that out of every 6 sucessfull entrepeneurs only one of them has never been bankrupt

Yeppity yep, and you know what else Henry, and I might even be willing to lay a couple of light ones on it, (not heavies), that for every successful entrepreneur there is probably half a dozen bankrupt ones.
Greg

[Greg Beetham]

Oo, I not sure I care for the sound of that one, an arm that attaches too the hotshoe is really looking for trouble, I'd much rather a stiff bracket coming from the tripod thread, then you can utilize the oc cable and oc shoe, then there is no danger of the camera shoe being broken by some unexpected event.
Greg

[Javelin]

well when they release the thing you'll see what it is. I didn't think it was a particularly good idea myself but it's only one mode of this units operation.

[bakubo]

Yeppity yep, and you know what else Henry, and I might even be willing to lay a couple of light ones on it, (not heavies), that for every successful entrepreneur there is probably half a dozen bankrupt ones.

Yes, that also is true. Again though, it is the reason apparently none of us are successful entrepreneurs. One aspect of being successful, not the only one, but an important one, is seeing the glass half full, not half empty and focusing on solutions, not problems. I have worked with successful entrepreneurs in the past and they definitely have a different mindset. I didn't mean to offend. I'm sorry.

Anyway, David is probably not even considering a product, I just threw the idea out to him in case he was wondering about it.

[David Kilpatrick]

I would not consider trying to prototype such a product, though I can see that with a spare 16mm lens and an Alpha extension tube plus suitable glassware it might be practical. I'd be quite happy to out the idea into the minds of Novoflex, or one of the many excellent Chinese adaptor makers, or Sony themselves. Otherwise I would never have mentioned it in public at all

By mentioning this concept on photoclubalpha's website, I remove for ever any possibiity of a restrictive patent being taken out by Sony or third parties on the principle, and indeed on some of the detail. It's impossible to patent something once it has been proposed or discussed (published) by anyone else. That throws the field open to all developers.

David

[bakubo]

I would not consider trying to prototype such a product, though I can see that with a spare 16mm lens and an Alpha extension tube plus suitable glassware it might be practical. I'd be quite happy to out the idea into the minds of Novoflex, or one of the many excellent Chinese adaptor makers, or Sony themselves. Otherwise I would never have mentioned it in public at all

That would be cool if someone does make it though!

By mentioning this concept on photoclubalpha's website, I remove for ever any possibiity of a restrictive patent being taken out by Sony or third parties on the principle, and indeed on some of the detail. It's impossible to patent something once it has been proposed or discussed (published) by anyone else. That throws the field open to all developers.

Somewhere you had mentioned that some company (maybe it was Zess?) already makes these things so even if you hadn't mentioned it here you probably couldn't have patented it. Also, you don't necessarily need a patent to make a product. Of course, if it is successful others might decide to give you some competition. I wonder if this sort of thing is something that could be patented anyway (since it already exists)? Is there a patent for 1.4x and 2x tele-converters, for instance? Aren't they basically Barlow lenses? There seem to be lots of companies making tele-converters.

Sounds like a really good idea though!

[Greg Beetham]

Yes, that also is true. Again though, it is the reason apparently none of us are successful entrepreneurs. One aspect of being successful, not the only one, but an important one, is seeing the glass half full, not half empty and focusing on solutions, not problems. I have worked with successful entrepreneurs in the past and they definitely have a different mindset. I didn't mean to offend. I'm sorry.

Anyway, David is probably not even considering a product, I just threw the idea out to him in case he was wondering about it.

No offense taken Henry, what's the worst that could happen, I could loose a couple of light beers...ha ha, and yes I'm reasonably familiar with the entrepreneural mindset, sort of the 'can do' approach combined with the glass half full ideal, and that's quite ok by me if that's what floats their boat. My approach to anything is a little more methodical I guess, I don't care about what is likely to sell, or flim flam, I think a solution should be able to withstand any kind of query or question being thrown at it, if it can't, it's not worth very much in my book...in other words, perfect is only just good enough.
Greg

ps. David, there hasen't been an adapter produced that reduces focal length and reduces the format-image scale at the same time before? Seems odd that it hasn't previously been thought of, what with all those brilliant opticians that have designed all those wonderful optics in the past.

[David Kilpatrick]

David, there hasen't been an adapter produced that reduces focal length and reduces the format-image scale at the same time before? Seems odd that it hasn't previously been thought of, what with all those brilliant opticians that have designed all those wonderful optics in the past.

There have been many, but they fit in FRONT of the lens as afocal converters and do not reduce the image circle, only the scale. The 0.8X and 0.7X converters made by Olympus, Minolta etc for digital still cams, and the 0.5X models for video, are well enough known. I have a 0.5X Bower here and a really horrible bit of glass it is, as well as huge.

Rear converters have of course existed in the past, and the first example was the Victorian Rapid Rectilinear lens, a symmetrical design where you could use just the front group to get (say) a 300mm focal length, or add the rear group (identical) to get 150mm. You needed, of course, to rack the bellows in for 150mm and out for 300mm. The original Schneider Symmar, prior to the Symmar-S, is a convertible lens based on this but with better corrections. I worked with these for severalk years, they were no longer actually symmetrical and I think the conversion was between 165mm and 210mm for one lens I had.

When I was 14 I discovered that simple Cooke triplet lenses consist of a positive rear group, and a negative front group, with the iris between. My father gave me his Zeiss Kolibiri which had a telescopic chrome tube in place of bellows; it had an f/4.5 Novar lens. By removing the front glass (it unscrewed) and pushing the chrome tube to a mark I made (using a groundglass to establish infinity) the 50mm lens became around 35mm, though the edges were not sharp unless closed right down. I used this to get a crude wide-angle. This was the reverse of adding a rear converter, it was in effect removing a front converter which was part of the lens design.

Don't forget the Twin Tamron, and many dual focal length 35mm compacts. Some used two lenses, others used two rear groups (effectively, two different value 'converters') with a switch. Also, don't forget the entire era of leaf shutter SLRs. Many used a fixed rear group (the prime group, with a real-image forming dioptric power) behind the iris/shutter, and then a range of front assemblies. Retina Reflex, Contaflex, Petriflex, Topcon other than RE - etc.

The history of convertible lenses and converters goes back to the very start of photography. The Zeiss cine converters currently sold are extremely complex relay optics costing thousands, and that is not what I am proposing. The extreme thin mirrorless body with a wide lens throat on the NEX is a unique new combination of factors. It opens the way to countless possibilities.

It has just occurred to me that Pen F lenses will be usable. The Pen F system used a 29mm register. The new micro 4/3rds system system mount register is 20mm, which also should allow adaptors, but it has a very narrow throad. The NEX has a 46mm internal diameter, about 4mm less than the Alpha mount. Micro 4/3rds is only 38mm, which is smaller than Leica screw (deliberate mistake?).

In fact every lens ever made apart from a few very speclialised items, even C-mount, will be adaptable to NEX. C-mount only needs a half millimetre recess for its very small screw thread to focus on infinity.

David

[Greg Beetham]

Very interesting post David, thankyou, I had this hazy thought about 6X7 or 6X6 or even 645 MF lenses with their reasonably large registers being able to be rear adapted to 35mm format, probably wouldn't be a great success though with their electronic leaf shutters getting in the way, the Bronica and Mamiya ones at least, not sure about Fuji, Rolli or Hassy.
Greg