Holga-rific tilt-shift mechanism

[fluffybunny]

Maybe this is a difference between EE and EF-S lenses. I have some “red dot” lenses but I’m going to be tied up for the next week or two so I may have trouble finding time to remeasure a different lens until then.

[Yoyo]

I believe that the only physical difference between the EF and EF-S is the color and shape of the mark and about 20 degrees.

The bayonet flanges themselves are identical as far as I know and can determine for myself. I’ve even heard that by using mirror lock-up, EF-S lenses can be used on APS-H and 35mm frame bodies.

[fluffybunny]

Got it. Still time challenged right now (no photos from me this week) so I will re examine my measuremnt method when I can.

[Yoyo]

I’m not sure if I mentioned it earlier, but I got the specs in my drawings from putting a Holga for DSLR (awesome cause it’s cheap and soft, nice for boudoir portraiture) on my scanner and then inserting the image into Visio, marking the center, drawing some radii to the points of interest, and then checking the resulting angles. Everything came out pretty close to 5 degree intervals, so I rounded them all off to the closest 5. I still haven’t taken a set of calipers to a Canon product yet, but I’ll get to it in a week when I’m back home. The Holga is nice since the bayonet flanges are the rearmost surface and it scans well, but I suspect that Holga’s tolerances are (necessarily) wider than Canon’s due to the low cost manufacturing methods they use.

[Yoyo]

http://shpws.me/dpN7
Here’s the current model uploaded to the 3d printing company site.

[fluffybunny]

Here’s the current model uploaded to the 3d printing company site.

Freakin awesome man! When do the go on sale? (Sorry I still have not been able to redo those angular measurements.)

[Yoyo]

Is there a draftsman in the house? Does anyone want to volunteer to proof the model first? It’s in Alibre which is free to try for a month (or as long as you keep adjusting your system date). And if you’re willing to be the first sucker, er, I mean, adopter, I could make it available for purchase when ever you like. Have you got a +10 diopter already?

[fluffybunny]

My old ones are 55mm but I would consider buying a cheap set to give it a go. What price will you be asking? I don’t have Alibre, I use A***cad mostly. If it will import I’ll look at it. What kind of proofing do you need?

[Yoyo]

You could get a step-down coupler from 58 to 55, or I could change the parameters to 55 for you.
As for price, I could have a 0% markup for Farktographers, it’d be the $94 list price.
Alibre is cheap and you get what you pay for. Unfortunately, I never learned Autocad, always some off-brand solid modelling package.

Proofing would just be looking over the individual bits to ensure that their design makes sense, and there’s not some obviously better design that I’ve got a blind spot for. As it is, each component is on the second white-page model, and they could probably stand to have a 3rd go round for half of them. There’s some inelegant kludges that I sort of slapped on at the end to make corrections. Also, I’m not entirely happy with the focus adjust threads, as Alibre doesn’t do helical sweep cuts very well, IMO. Anyway, I’ll be back on the road tomorrow until about Sunday.

[Yoyo]

Proofing the model should reveal things like I forgot to include like the recessed groove around the front end to make it easier to paint on a red stripe. 🙂 I get loopy when I’m low on sleep.

[hunches]

It’s in Alibre which is free to try for a month (or as long as you keep adjusting your system date).

This reminded me of a trick with ‘free for a month’ software that can be fooled by your system clock:

1. Set clock to the year 2200.
2. Install software.
3. Set clock back to current year.
4. Giggle at the ‘You have 32768 days left on your free 30 day trial’ messages.

We did this with zMUD back in the day 🙂

[fluffybunny]

Eh, I looked at my old macro filters and they are +1, +2 and +3 so I would be buying a cheap set. Count me in for buying one. I can proof if A***cad will read the format. Is there a file to download somewhere on that shapeways site?

[Yoyo]

Eh, I looked at my old macro filters and they are +1, +2 and +3 so I would be buying a cheap set. Count me in for buying one. I can proof if A***cad will read the format. Is there a file to download somewhere on that shapeways site?

You will definitely need more than +6 (less than 133mm focal length). The Adorama house label +10 is about $24, and you can get a name brand for around $40, but maybe the cheap one is better for the Holga-esque feel.

The data files have ad_prt and ad_asm extensions. I exported a stl for upload to Shapeways (dims are mm). I have no idea what formats you can read. I uploaded the relevant files to Skydrive http://sdrv.ms/No6KEx . Part export options for me include IGES, Solidworks part, and Parasolid part. If you can’t import one of those, then the name brand is slipping.

[fluffybunny]

I downloaded that set of files and will try to look at them this weekend. Pretty sure I can read IGES and Solidworks.

[Yoyo]

We got a bite on the Shapeways page. I’ve also made the model purchasable.

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