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Did I do a dumb thing? Novoflex Pigriff B
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PostPosted: Thu Sep 05, 2019 8:39 am    Post subject: Did I do a dumb thing? Novoflex Pigriff B Reply with quote

A Novoflex Pigriff with 600mm lens came my way. It is is fairly good condition but the lens is fungus damaged and an expert assessed the lens as etched.

It works, after a fashion, with my Pentax K-5 but I would like it to be as good as I can make it.

So far I have fitted Pentax K mount to the rear of the bellows and adjusted focus travel to give infinity (or near infinity) with the full trigger travel and bellows fully in.

https://www.pacificrimcamera.com/rl/00314/00314.pdf



....picture from net but almost what I have.


Now the question is will a 'telescope objective' give usable results in this rig? Specifically https://www.aliexpress.com/item/32820485581.html the dumb part is that I have already ordered it!!!

John


PostPosted: Thu Sep 05, 2019 10:15 am    Post subject: Reply with quote

It wouldn't work with a telescope tube except for very short focusing distances, but just the objective on it's own could be made to work.

You may need an additional tube of the right sort of diameter, so the element can be mounted it's focal length from the sensor.

It seems quite an expensive way to play with an inferior lens to me. I'd go for a close up supplementary/'filter' in preference or a similar achromatic objective from somewhere like Astroboot or surplus shed...

You may find this https://www.flickr.com/groups/homemadelens/discuss/72157622612617105/ useful a tutorial for making your own lenses, combining multiple elements...

If I ever get round to trying something similar I'll probably use a standard helicoid for focusing too as I have several of these already & they are much easier to source than that nice squeeze focus rig.
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PostPosted: Thu Sep 05, 2019 1:35 pm    Post subject: Reply with quote

That will be fun to try (I assume you got the 600mm focal length). The novoflexes are not telephotos so the length of the barrel for focus etc will be correct and there is no issue matching another optical group. However, looking at mine, the diameter of the original element is ~ 74mm so it's not a straight swap, you have some diy'ing/fitting to do.

One more thought: I vaguely remember coming across some info about individuals getting good optics for diy telescopes etc from US army surplus... could be worth browsing around, asking on some forums.


Last edited by marcusBMG on Thu Sep 05, 2019 2:43 pm; edited 1 time in total


PostPosted: Thu Sep 05, 2019 1:46 pm    Post subject: Reply with quote

I used to have the 600mm some 25 years ago. I sold it quite soon, because it was too heavy, and because the landscape images were low in contrast (too much haze in the air, not a mistake of the lens). In addition, there were the obvious problems with low speed (f8.0), field curvature and blurred images (no stabilizer). These days, using high ISO, in-body stabilization and post-processing, the Novoflex lenses are much more useable.

Now back to your question: I don't think that the bellows in its fully retracted position, is a source of concern. As far as I remember, it is quite well built. You always can take ten test images of the same subject and check whether the image quality is changing ...


PostPosted: Thu Sep 05, 2019 6:41 pm    Post subject: Reply with quote

Thanks for the comments and advice.

Yes it is quite heavy and I am working on a bi-pod support which I hope will make it easier to handle. There are a number of old long lenses in my stash and I must say the neither gravity nor atmosphere are our friends when trying for those long shots.

I will not destroy the existing cell so I will be making a slightly larger cell to accommodate the size lens that is winging its way from Cathay. This might leave me with issues with infinity focus unless I shorten the tube, easy to do, or make a new tube which would also be easy enough. If I were to mount the camera directly to the slide grip unit that would shorten the light path so that would be another option.


Also thanks for the link to the DIY lens info which I will study when I get home later in the day.


John


PostPosted: Fri Sep 06, 2019 12:52 am    Post subject: Reply with quote

I assume most of the important connection points on the Novoflex are threaded, I don't see any reason you couldn't make those optics work for you, mounting the optics and getting the registration & spacing right will be the most challenging bits.

I don't know how easy it would be to swap the optics, that would depend on dimensions and formula.


PostPosted: Fri Sep 06, 2019 3:03 am    Post subject: Reply with quote

Hi LightShow, the optics are not at all complicated as the Novoflex is basically a telescope with an objective lens and no other. Yes, the various connections are mostly screwed with the only complication being the diameter of the tubes do no match any I can easily buy here.

John