DIY Meniscus Test Pics

[SteveH]

All,
As some of you may recall, I've been messing around with making my 'own' lens. The original threads can be found here:

Lens - (there was a url link here which no longer exists)
Shutter - (there was a url link here which no longer exists)

So over the weekend, I took the temporarily assembled lens out for a test - to be sure it was what I wanted before I began cutting metal.
Here's the negs. Note however that when going ghetto, ghetto is all you can go.....My scanner doesn't play well with Linux, and I have yet to bother to purchase one that does (I had ordered a 4870...But after getting one that was DOA, I discovered that Epson isn't the best company in the customer service dept) . So....In a disgusting gesture, I have placed the negs on my light table, photographed them with my digicam (ca. 1999), and inverted them. Please don't judge such things as exposure and contrast, as its impossible to see. Also, be take notice of relative sharpness, not how sharp it looks on screen. One of these years I'll get a scanner and do it right.

f/3.8

f/5.6

f/11

f/22

In the other thread, I commented about how the distortion seems to be dependant upon bellow draw just as much as it does on the aperture. You can see what I mean by looking at the f/5.6 shot (closer than infinity), and then looking at the f/11 shot (infinity).

Thoughts ?

-Steve

 

[Ole]

The astigmatism is - amazing!

And yes, I would expect that to be dependent on both bellows draw and aperture.

I've just developed my first shots with a "periscope" lens - two simple meniscuses (meniscii??) with an aperture between. I was very suprised by the sharpness and evenness of a 200mm (appx) on 5x7" film. Nothing like the astigmatism you've got!

 

[SteveH]

Thanks Ole. Do you have any scans ?
Surprisingly, the lens is pretty sharp (believe it or not..). In the neg, the bark texture on the 'Y' shaped tree in the last shot is *slightly* visable. Even on the wide open shot, the leaves and texture on the bush are clearly visable

 

[Ole]

Thanks Ole. Do you have any scans ?

Ah... Ummm..... Well........

Not right now. The negative was just now dry enough to be put away. It's now late evening here, and in 12 hours (aaargh!) I'm due to check in to a plane hwich will take me a bit north, where I'll catch a helicopter for a ride out to an oil platform.

But in 14 days (a fortnight) I'll back home, and I'll definitely make some prints and scan them.

And I'll print the other 200 negatives I've been developing over the past week, too...

 

[Jerevan]

Cool, swirly stuff. Make a portrait and print it, borrow a flatbed scanner and show us the beautiflful swirliness! I like the f/3.8 and f/11 ones. Do you have flare issues (especially at f22) or is it just the unmentionable thing from 1999 that makes it seem so?

Thumbs up. Way to go!

 

[Terence]

Very nice. Did she drink that whole bottle of wine by herself? That might explain the haziness . . .

 

[SteveH]

HAHA. Actually that wasn't wine. I had made some spearmint tea and I didn't have a container large enough, so I used a beer growler. I do wish I had it full of beer, but it was still put to a good use I suppose.
I don't think I have flair issues....Its just the negative-computer issue that caused all kind of stuff to show. Mainly, its just uneven illumination from the light table.
Im not going to take any more photos with it until I have the lens barrel finished (as I took the lens down to the shop last night). Once that is complete, and I make up some real stops, we'll see what happens.

 

[SteveH]

Ah... Ummm..... Well........

Not right now. The negative was just now dry enough to be put away. It's now late evening here, and in 12 hours (aaargh!) I'm due to check in to a plane hwich will take me a bit north, where I'll catch a helicopter for a ride out to an oil platform.

But in 14 days (a fortnight) I'll back home, and I'll definitely make some prints and scan them.

And I'll print the other 200 negatives I've been developing over the past week, too...

I'll look forward to seeing them !

Have a safe trip.

 

[ineffablething]

Actually, I have a lens that produces a similar look. It's an unmarked lens with fstops from f5-f32. Though in practice the maximum fstop seems more like f3.5. It's not a meniscus lens, it's got multilple elements and an iris aperture. This is a shot on 8x10 polaroid,wide open.

I'll look forward to seeing them !

Have a safe trip.

 

[SteveH]

Very Cool ! Any idea what construction your lens is ?

 

[ineffablething]

No clue,actually. It's unmarked. I don't think I've ever had a lens with this combination of character "flaws."

 

[SteveH]

Do you have any photos of the lens ? If its a multi-element, most likely its a petzval - especially if its pretty large in diameter (which Im assuming it is judging by its speed).
Either way, it looks pretty neat !

 

[marko_trebusak]

Steve, I can only see photo at f11, others are marked "unavailable", but it sure is a neat set of distortions you got with your lens. This trend in LF community is very interesting indeed. Who needs "big four", if we can make our own lenses ?

Marko

 

[ineffablething]

YOu can see it up on ebay now, under my user name "ineffablething". I don't know if it's a petzval or what, but it does have that sort of petzval swirl, along with some crazy "whoosh". The front and the rear element are both about 2.5 inches across, the whole lens is only about 4 inches long.

William

Do you have any photos of the lens ? If its a multi-element, most likely its a petzval - especially if its pretty large in diameter (which Im assuming it is judging by its speed).
Either way, it looks pretty neat !

 

[SteveH]

Sorry.....Flickr is having a temper tantrum.

 

[smieglitz]

No clue,actually. It's unmarked. I don't think I've ever had a lens with this combination of character "flaws."

That's so very cool.

Joe