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  1. Replies
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    Re: Forum Growth.....or not?

    I think we should ban Donald Trump from this forum. Just because everyone else is doing it...
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    Re: getting glass CLEAN, how do you do it?

    Seems like a waste of a good India Pale Ale...
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    Re: Tintype fogging while drying

    I second this.
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    Re: getting glass CLEAN, how do you do it?

    I've found the main culprit in getting glass spotlessly clean isn't the cleaner used, it's the cleaning cloth.
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    Re: Secure selling?

    Paypal is the norm, but really, it's up to the buyer and seller to work it out however they are comfortable.
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    Re: Fast High Quality DIY GG

    Helpful hint: Use a second piece of glass to do the grinding, and you get two pieces of ground glass for the same time and effort.
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    Re: Which are the fancy lenses??

    Yes it is. You shoot some hokey bokey and you turn yourself around.

    That's what it's all about.
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    Re: f/5.6 or slower 300mm for 8x10?

    The B&J is a fairly heavy camera, at the far end of what most people would consider a "field camera". Trying to save weight on the lens is wandering into the area of diminishing returns, like...
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    Re: Which are the fancy lenses??

    For some of the more knowledgeable users, the shutter is as important as the lens...
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    Re: Fixing bellows corners

    That's the usual method for bellows with very worn corners. Pretty obvious advice, but:

    Stretch out the bellows as much as you dare before taping.

    Use a flexible fabric paint (available at...
  11. Re: What is this shutter on a Vesta Portrait lens?

    I'm always right, and I never lie! :rolleyes::rolleyes::rolleyes:
  12. Re: What is this shutter on a Vesta Portrait lens?

    Best to assemble the lens in its new shutter and determine the f/stops by measuring. The new Alphax may not close down at the same linear rate as the old shutter.
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    Re: Putting together lenses from scratch

    Primitive Photography: A Guide to Making Cameras, Lenses, and Calotypes, by Alan Greene, has a 58-page chapter that does a decent job with the basics.
  14. Re: Tilt an old lens a teeny bit off axis to improve image. Anyone ever heard of this

    Well, "Tessars types, Commercial Ektars, Dagors, some Artars" are all pretty flat field, so it's not field curvature. Maybe the camera was out-of-kilter, and needed a degree or two of front tilt to...
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    Re: What's your Go To LF body & lens?

    The more I eat and the older I get, the larger the format of my body seems to be.

    Not yet sure about the lens, though...
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    Re: Putting together lenses from scratch

    The first thing you need to do is build an optical bench to test the various configurations. Otherwise, you won't know whether what you're building works until after it's built. Just a few mounts...
  17. Re: Tilt an old lens a teeny bit off axis to improve image. Anyone ever heard of this

    Unless you're using Petzvals or meniscus lenses, I doubt it was field curvature. Regardless, front tilt won't remove field curvature. No movement will. Could be focus shift from stopping down, but...
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    Re: Social Media 101

    But think how much better large format photography looks on a cell phone!
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    Re: What focal length, taking aperture used?

    That was my next guess.
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    Re: What focal length, taking aperture used?

    Not much to go on...

    90mm, f/22?
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    Re: 4x5 Portrait lens & Chamonix F2

    A second for Hugo's suggestion of a Dagor; nice for portraits wide open and sharp with lots of movements closed down. And you can probably find a newer one in a decent shutter.

    If it weren't for...
  22. Re: Diffraction. When does it really matter with LF?

    That makes sense! Thanks!

    But is chromatic aberration a geometric effect? :confused:
  23. Re: Diffraction. When does it really matter with LF?

    That makes sense. But the diffraction limits calculators I've seen go by f/stops, not actual aperture size. And of course, f/stop dimensions change with focal length, as that's the "f" in "f/stop".
  24. Re: Diffraction. When does it really matter with LF?

    In our case, that would be an opening in the photon-wave-amplitude size, something well below f/64 for our lenses.

    One thing I don't understand about diffraction is why it is affected by focal...
  25. Re: Diffraction. When does it really matter with LF?

    Agreed, Drew, but which other aberrations are ever corrected to perfection, not just reduced or avoided?
  26. Re: Diffraction. When does it really matter with LF?

    Diffraction can be corrected by opening up the aperture. Just like you can correct spherical aberration or curved field by closing down the aperture.

    But one can also correct spherical aberration...
  27. Re: Diffraction. When does it really matter with LF?

    Why isn't diffraction considered an optical aberration? It's missing from the conventional list of aberrations.

    Late night pondering... :confused:
  28. Re: Diffraction. When does it really matter with LF?

    Jim's post reminds me of a little trick I learned from ancient markings on a couple of my old shutters: put little paint/pencil marks on the aperture scale at 1 inch and 1 centimeter. It makes the...
  29. Re: Diffraction. When does it really matter with LF?

    For large format, this is key. If you're contact printing, (no enlargement of the negative), forget diffraction. It will barely show up at f/256.



    Nitpicking, but isn't 1:1 and f/16 nominal...
  30. Re: Diy tripod, plans, advice and links to plans please

    At my age, I'm wondering whether a balsa wood tripod would work...
  31. Re: Diy tripod, plans, advice and links to plans please

    The Ries tripods are made from Hard Maple/Rock Maple/Sugar Maple (all the same), though the company has recently been offering other woods on "custom" tripods.
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    Re: Certificate Expired

    It was all a hoax! Fake certificates are the Reptilians' way of controlling our minds! Spots on your negatives are caused by having sex with demons in your dreams! Watch You-Tube for the real...
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    Re: Certificate Expired

    Yup, I got it too.
  34. Re: Bellows Extension Factor & Flash Photography

    Most strobes have variable output. You can also use films of different ISOs, if you aren't committed to one film in particular. ND filters on the lens, or over the strobes, (those on the strobes...
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    Re: Good light lens for 8x10

    Modern coated Dagors are always nice, reasonably light, and fairly bright.
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    Re: Meniscus lens iris "sweet spot"???

    If I was talking about coma, I would have said coma, as I did when talking about coma earlier. I didn't post a link.



    Yes, and you can also increase spherical aberration by altering the...
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    Re: Meniscus lens iris "sweet spot"???

    As you change the position of the stop, you change where rays coming from off the optical axis though the aperture strike the lens. In a lens with significant spherical aberration (like a meniscus),...
  38. Re: Do I need a contrast or ND Lens Filter for Verito 18 F4?

    I worked with one in a studio many times without. No problem, even wide open. If you're working outside in the daytime, yep, you'll need an ND filter or a shutter, (do a search for "Galli shutter",...
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    Re: Meniscus lens iris "sweet spot"???

    Just a note that aperture position is one of the "design freedoms". There's some choice involved because different positions are the "sweet spot" for minimizing different aberrations. The sweet...
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    Re: 20x24 lenses

    If you're doing still lifes, the Tessar may well cover at close distance.
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