Wide angle and K3 with M42 mout

Raz Birger · June 29, 2009

Hello guys,

I have a Krasnogorsk-3 with M42 mount and I want to get a wider angle of view.

Would it be wise to buy a wide angle attachment like this one?

http://www.cavision.com/optics/industrial/LWA07X77.htm

I think these attachments were made for lenses that have a wider angle than what you get with Krasnogorsk's Meteor at 17mm and it may not be effective to use.

Peleng 8mm would be more expensive and I am not looking for the distortions of a fisheye lens (I know it's less visible on 16mm film, but I watched some footage and it is still visible enough).

Is there any other solution or should I go for the attachment?

Best Regards,

Raz Birger.

Olex Kalynychenko · June 30, 2009

Hello guys,
I have a Krasnogorsk-3 with M42 mount and I want to get a wider angle of view.

Would it be wise to buy a wide angle attachment like this one?

http://www.cavision.com/optics/industrial/LWA07X77.htm

I think these attachments were made for lenses that have a wider angle than what you get with Krasnogorsk's Meteor at 17mm and it may not be effective to use.

Peleng 8mm would be more expensive and I am not looking for the distortions of a fisheye lens (I know it's less visible on 16mm film, but I watched some footage and it is still visible enough).

Is there any other solution or should I go for the attachment?

Best Regards,

Raz Birger.

I think, to use of 0.7x adapter possible with Meteor-5 17-69 mm zoom lens.

Meteor-5 have M77 screw mount from front side and 0.7x adapter can be fit.

Any case, you can test.

Maximum wide angle of view must be like 0.7x 17 mm = 12 mm.

K-3 with bayonet mount can be use with upgraded 16OPF-12 zoom lens 10-100 mm.

10-100 mm zoom lens can have 0.75 x front wide angle attachmnet and work very fine with K-3 + 10-100 + 0.75 x.

Raz Birger · June 30, 2009

I think, to use of 0.7x adapter possible with Meteor-5 17-69 mm zoom lens.
Meteor-5 have M77 screw mount from front side and 0.7x adapter can be fit.

Any case, you can test.

Maximum wide angle of view must be like 0.7x 17 mm = 12 mm.

K-3 with bayonet mount can be use with upgraded 16OPF-12 zoom lens 10-100 mm.

10-100 mm zoom lens can have 0.75 x front wide angle attachmnet and work very fine with K-3 + 10-100 + 0.75 x.

Thank you for your answer Olex.

I can't test the adapter, I have to order it, it's not in stock wherever I look. There are only attachments for tinier screws like 72mm 58mm 37mm.... Larger than these should be ordered.

If I had a bayonet K3 it would have solved the problem, but I have already got one with M42 mount.

Are you sure about your calculation? I have always thought the ratio (0.7x) is of the angle of view and not of the focal length. So the calculation should be like this:

Angle of view formula: 2*tan-¹(0.5*L/F)

(L - length of the film, in 16mm it is about 10mm. F - focal length, 17mm Meteor's widest)

2*tan-¹(0.5*10/17) ≈ 32.8°

Then 32.8/0.7 gives us 46.8°. Using the formula the focal length of this angle is 11.55mm. OK it's not so far from 12mm like you said :lol: .

Anyways, I am also wondering how such an attachment will effect focusing? (I am talking about staying on the widest angle without zooming).