[melander]

I thought that we could have a thread about lenses that we cant fit on the K-1 due to the overhang.

Myself I had to modify my Helios 40-2 85/1.5 due to a very large backplate.
Had the mecanic at work to do some quick and dirty fix for this in the workshop.

Seeing a lens spinning in the lathe was a new experience, having a surgery glove on from the front of the lens to protect it from metall dust.

Attached Images

 

[Edgar_in_Indy]

You mean that Helios isn't doing the repair for free?? Wow, their customer service has really gone down hill!

And this, after Soviet spies risked it all to obtain the only known copy of the super-top-secret specifications of the K-mount!

[melander]

I tried to send it to them

Helios
Moskov
Russia

Didnt work

[D1N0]

In Soviet Russia we adapt camera to lens! Send K-1.

---------- Post added 22-06-16 at 15:45 ----------

Has anyone tried a Helios 44m yet (not 44-2) It also has a wider than average back.

[goatsNdonkey]

I don't have a Helios...yet...but I think the OP's question is important to anyone who's greatest (if not only) motivation for Pentax love is backward compatibility with older lenses of many makes if they share mounts that Pentax has designed/used. Are there others besides the Helios 44-2?

[pathdoc]

Perhaps you should consider modifying the thread title (if possible) to "Other than Sigma".

[Topsy]

Has anyone tried a Helios 44m yet (not 44-2) It also has a wider than average back.

If it's the same as the 44k-4 it should easily fit!


I'm sure the Jupiter 6 won't fit (afaik it also won't fit the k50).
Would look interesting though


What I'm personally more worried about is the rear element on lenses hitting the larger mirror. The MIR-1 appear to clear it at 1mm max.
I guess the Berolina Westromat for instance would hit it easily.

[D1N0]

Pentax isn't Canon. The floating mirror mechanism will prevent most trouble:

[funktionsfrei]

Whatever that floating mirror thingy is for, it is not primarily responsible for the mirror not hitting the rear lens element.

SLRs from the film era such as the ME Super or P30 had no floating mirror thingmabob, but are mechanically compatible to everything you can mount on an APS-C DLSR utilizing the K bayonet.

So it is quite obvious that it's possible to build a full-frame SLR without it's mirror hitting the lens, and without a floating mirror gimmick.

[D1N0]

Whatever that floating mirror thingy is for, it is not primarily responsible for the mirror not hitting the rear lens element.

SLRs from the film era such as the ME Super or P30 had no floating mirror thingmabob, but are mechanically compatible to everything you can mount on an APS-C DLSR utilizing the K bayonet.

So it is quite obvious that it's possible to build a full-frame SLR without it's mirror hitting the lens, and without a floating mirror gimmick.

ricoh:
In order to accommodate the 35mm full-frame image sensor and cover the light flux of the large viewfinder with a nearly 100-percent field of view, it was necessary to increase the size of the main mirror and mirror box. To minimize the size of the mirror box, PENTAX has developed a new mechanism that retracts the main mirror as it swings upwards.

[funktionsfrei]

Yeah. That's what Ricoh says. But what made Pentax wrong when they were designing FF SLRs with large viewfinders and without floating mirrors? These cameras were FF cameras, so they had appropriately sized mirrors and mirror boxes.

Of cource the mirrors size had to be increased - when compared to the mirror used in an APS-C SLR. But in comparison to a FF SLR? Huh?

Is it all "smoke and mirrors"? Marketing BS bingo?

[D1N0]

The mirror box in slr was deeper because they didn't have a big eletronics board sensor shake mechanism to reckon with, so the mirror never left the box in the front.

[Na Horuk]

Ah, great thread! Pentax needs to keep this in mind for future models and allow a little more space.

Has anyone tried the Samyang 24mm Tilt Shift lens? It had problems on K-30.

So it is quite obvious that it's possible to build a full-frame SLR without it's mirror hitting the lens, and without a floating mirror gimmick.

Yeah, I don't understand this. So many SLRs had big viewfinders, big mirrors, and K-mount (or even the smaller diameter m37, m42) without a problem. And some lenses back in the day used to recede further into the body than modern ones. Even fast lenses or WA or telephoto lenses had no problem. Today, people blame the K-mount for having too narrow diameter for fast lenses, too short register for big viewfinder, too long register for compact designs, just everything. It used to work well, why would it not work now? Why is not now too big and too small at the same time? Figure its mostly just negative hype

[funktionsfrei]

The mirror box in slr was deeper because they didn't have a big eletronics board sensor shake mechanism to reckon with

So, you think the distance between the focal plane (that is, the sensor's or film's surface) and the actual shutter metal blades has been increased on DSLRs to acommodate the SR mechanism? That would be an explanation; the shutter's nearer to the rear end of the lens, thus reducing the depth of the room available for the mirror.

Has anyone tried the Samyang 24mm Tilt Shift lens? It had problems on K-30.

What kind of problems?

[Na Horuk]

What kind of problems?

If I remember right, it could not be shifted as it would hit the protrusion beneath the flash. The K-50 did not have this problem. You could still use it on K-30, but not at all settings/directions. There were threads about this back when the K-30 was still new