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  1. #41

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    Ok, this next image may not seem much but its quite important to me, here is an in camera cyanotype negative using the speed graphic and the 7 dioptre filter lens, its quite dark out now, long exposure (something like 20 minutes) and the cyanotype was created a while back so not that fresh.

    It might not seem much but this is a test shot against that test window again, its not very clear due to the paper and lack of UV at this time, but you can kinda of make out the window edges and the apartments across the way (the brickwork is a different colour:



    Here is what it would look like when looking through the ground glass (image flipped correct way up)


  2. #42

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    Quote Originally Posted by VPooler View Post
    Or, forget the springs and add solenoids and electronic control :P That's what I am going to do.
    Yeah, I could perhaps look at doing something like that with a simple solinoid, the issue I have is that I will have some fairly large lenses to cover lol

  3. #43

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    Same here. I am going to start studying electrical engineering and I also have a course of mechanics included so maybe I can torture some science people into helping me lol

  4. #44

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    Quote Originally Posted by VPooler View Post
    Same here. I am going to start studying electrical engineering and I also have a course of mechanics included so maybe I can torture some science people into helping me lol
    I am thinking perhaps something like a pivoted flap with an actuator at one end, then you could change the distance from the pivot to give a faster shutter, the close the actuator is connected the faster it would be and you would only need to have 1 speed on the actuator.

  5. #45
    Steve Smith's Avatar
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    I think the best design of shutter for DIY construction is the type found in Kodak box cameras.

    Easy to repair and would scale up quite easily.


    Steve.
    "People who say things won't work are a dime a dozen. People who figure out how to make things work are worth a fortune" - Dave Rat.

  6. #46

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    Quote Originally Posted by Steve Smith View Post
    I think the best design of shutter for DIY construction is the type found in Kodak box cameras.

    Easy to repair and would scale up quite easily.


    Steve.
    I have a Kodak Six-20 and took the front off, just need to work out what does what lol it would be set to 'T' for this shot rather than 'I', I just need to figure out what is happening when the shutter fires as there are different springs and plates moving lol.




  7. #47

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    Interesting idea that raises questions.

    Why are there no short fast meniscus lenses with high coverage on the market? Where are the users? If these lenses are so wonderful, why do we use other types?

    OP, I take it you're trying to make unique images that won't be enlarged. Is this correct?

    In a way, it brings to mind the craze for the great new Lomo Petzval. That craze raises the question of why, if the Petzval type is so wonderful, it pretty well disappeared from the market long ago. Low coverage Petzval types are still around and can be very good, but ... For example, Itek made an 8 element 13 inch/3.5 "field flattened Petzval" for USAF that resolved 200 lp/mm 6 degrees off axis wide open, i.e., didn't quite cover 6x7.

  8. #48

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    Quote Originally Posted by Dan Fromm View Post
    Interesting idea that raises questions.

    Why are there no short fast meniscus lenses with high coverage on the market? Where are the users? If these lenses are so wonderful, why do we use other types?

    OP, I take it you're trying to make unique images that won't be enlarged. Is this correct?

    In a way, it brings to mind the craze for the great new Lomo Petzval. That craze raises the question of why, if the Petzval type is so wonderful, it pretty well disappeared from the market long ago. Low coverage Petzval types are still around and can be very good, but ... For example, Itek made an 8 element 13 inch/3.5 "field flattened Petzval" for USAF that resolved 200 lp/mm 6 degrees off axis wide open, i.e., didn't quite cover 6x7.
    I am indeed trying out making my own lens that makes unique images that won't be enlarged - although I am able to scan them in and make larger digital negatives. I feel that today's lenses kinda of lack something that the original lens designs had, sure older lens designs aren't as sharp and didn't have loads of corrective lenses but they were simple. I am looking to build a lens (and shutter) in keeping with the camera I am designing, I am not interested in tack sharp images but am more interested in making an image and being able to say that I made it. Sure I could just bolt on one of my lenses (or indeed my 1913 Zeiss London Tessar) but I didn't build it, this is more of a learning experiance as well for me and hopefully is for others.

    I saw that Lomo Petzval lens and personally don't like the whole 'Lomoisation' of some of the historic processes and lens designs to get 'the look' - I guess its better than instagram where they try and make images look like images that I could reproduce with any of my older cameras lol.

    I also wanted to show that you can get into LF cheaply and have some fun with it, I think the cost so far for my LF camera is at around £15, I do already have a speed graphic so could use it to test out different lenses before trying them on my DIY camera. I have very basic tools and little to no experiance in building cameras which I guess is why I am coming up with random questions and ideas as its all new to me in respects to building certain components.

    I should be able to produce a wide fast lens, faster than other lenses commercial available due to the fact that the image won't be perfect and it will have all sorts of imperfections in it, which is fine as I am still producing an image - its why I am going with big optics as a stopped down larger lens should perform better than a wide open smaller lens in terms or diamter of lens exposed to light.

    Its just a bit of fun, just want to see what I can do with some off the shelf items and a few basic tools

  9. #49

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    sure older lens designs aren't as sharp and didn't have loads of corrective lenses but they were simple
    I don't agree. Ancient lenses were quite sharp and Petzval types were quite fast for their focal lengths, even by today's standards. Modern lenses have greater coverage, that's all. Ole Tjugen, who'd posted here a lot, used to argue that a decent Petzval or Aplanat used correctly produced sharper images than a decent modern anastigmat.

    That old lenses aren't sharp is a canard based on lens abuse, i.e., using the lenses on formats larger than they were made to cover. Used as intended ancient Petzvals don't give the highly desirable nauseating swirlies.

    Menisci such as you're working with have tiny coverage, i.e., circles of good definition, even at small apertures. If that's what you want, though, they may well be what you need.

    I do suggest, though, that you calculate a little more and think more about your photographic ends. I have the impression that you're fascinated by selective focus, i.e., very narrow depth of field. Fine, wonderful. I suspect that y'r 1913 Zeiss London Tessar (a relative rarity, by the way) will give you the selective focus you want if shot wide open.

    As my wife often tells me, what you're doing is harmless and keeps you out of worse trouble. I haven't lost sight of the fun factor or the joy of working things out for oneself so I'm not trying to talk you out of doing what you enjoy. Quite the contrary. By all means continue and have a good time.

    Good luck, have fun, keep on reporting y'r progress,

    Dan

  10. #50

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    Thanks Dan, I know that the centre of the lens performs the best in terms of image quality and doing some of the basic tests of stopping the lens down helped a lot, I just need to make sure that the image circle is large enough for the 5x4 negative. I will be going with a lens with selective focus for portraits with a longer focal distance and also a wider landscape lens which won't be as large, I would then move onto a slightly slower lens using slightly more expensive optics to build something like a double Gauss lens.

    I am aware that my 1913 Zeiss London lens is fairly rare due to it being the last year of production in the UK before production was moved to Germany owing to WWI, I find it an interesting lens as it has f23 as an f stop rather than f22 being the more modern standardised number. I will also look at shooting that lens as well, its a 15cm lens so would be a good 'normal' focal distance.

    I am very interested to find out what sort of image the portrait lens will make due to the large elements I am using - a key thing to note on this project is that I am doing things as cheap as possible although I will also look at building a smaller camera which would allow for different optics.

    A single achromatic doublet lens would probably cost as much as a complete lens and barrel for my first lens lol I would in time be building more advanced lenses with some different corrective elements in them, its just a bit of fun to be able to re-purpose things to make something else.

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