[Adam]

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I've recently added an aperture blade count filter to our lens search system:
Pentax Lens Search | PentaxForums.com

For this to work as expected, we need to complete missing aperture blade info for the following lenses. If you own any of them, please check how many aperture blades the diaphragm has, and post in this thread. Thanks in advance!


K-mount

SMC Pentax-M 35mm F1.4 (I know this was only a prototype, but I'd rather not guess in case someone has more info on it)

645 mount

smc Pentax-A* 645 300mm F4 ED[IF]

M37

Takumar 50mm F3.5
Takumar 100mm F3.5
Tele-photo Takumar 500mm F5

M42

Fish-Eye-Takumar 17mm F11
Super-Takumar 20mm F4.5
Takumar 35mm F4
Auto-Takumar 55mm F1.9
Takumar 83mm F1.9
Quartz-Takumar 85mm F3.5
Ultra-Achromatic-Takumar 85mm F4.5
Takumar 100mm F2
Takumar 100mm F3.5
Takumar 105mm F2.8 (model 2)
Super-Multi-Coated Takumar 120mm F2.8
Tele-Takumar 400mm F5.6
Takumar 500mm F4.5
Takumar 500mm F5 (early)
Takumar 500mm F5 (late)
Super-Multi-Coated Takumar 1000mm F8
Takumar 1000mm F8
Tele-Takumar 1000mm F8

6x7

Takumar 6x7 800mm F4
Super-Multi-Coated Takumar 6x7 800mm F4
SMC Pentax-6x7 800mm F4
SMC Pentax-6x7 800mm F6.7 ED[IF]
SMC Pentax-M* 67 800mm F6.7 ED[IF]

Adam
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[G and T]

I can help with a few of these,
Auto-Takumar 105mm f2.8 has 8 aperture blades,
Super Takumar 300mm f4 has 6 blades
smc Pentax-A 645 55mm f2.8 has 8 blades
smc Pentax-A 645 75mm f2.8 has 8 blades
smc Pentax-A 645 150mm f3.5 has 8 blades
smc Pentax-A 645 200mm f4 has 8 blades

Glenn

[alvane]

SMC Pentax 67 90-180mm F5.6: 9 blades
SMC Pentax Zoom 67 90 180mm F 5 6 Lens for Pentax 67 67II 1736 | eBay

smc Pentax-A 645 45-85mm F4.5: 8 blades
EXC SMC Pentax A 645 Zoom 45 85mm F4 5 Medium Format w Cap from Japan 525 | eBay

[monochrome]

I can do Super Tak 35/2 - but I'll have to figure out which version I have

[GUB]

Super-Multi-Coated tak 28mm 3.5 and Super tak 28mm 3.5 (49mm filter) both have 5 blades.

---------- Post added 04-27-16 at 11:41 PM ----------

I have a super tak 55 f2 as per the left hand image (which I take as late) and it has 6 blades

---------- Post added 04-27-16 at 11:49 PM ----------

Super tak 135 f3.5 model 1 -- 6 blades

[lytrytyr]

For this to work as expected, we need to complete missing aperture blade info for the following lenses.

Q
03 Fish-eye 3.2mm F5.6
04 Toy Lens Wide 6.3mm F7.1
07 Mount Shield Lens 11.5mm F9
05 Toy Lens Telephoto 18mm F8

Don't these all have a fixed circular aperture?
So either one "blade" or infinity (number of tangents),
depending on how you count!

[marcusBMG]

SMC takumar 55mm f2 (late model with rubber focus) 6 blades
auto takumar 35mm f3.5 (1st gen) 5 blades

[Aggie89]

Takumar 55 2.2 has 10 blades. Just rebuilt the iris on mine a couple days ago which gave me plenty of opportunity to count the blades...over and over.

M37 Takumar 83 F1.9 has 20 blades

M37 Tele-photo Takumar 135mm F3.5 has 16 blades

[jatrax]

Super-Multi-Coated Takumar 20mm F4.5

S-M-C Takumar 20mm f/4.5 has 5 blades

[Odinz]

Super-Takumar 28mm F3.5 (model 2) - 5 Blades
Super-Takumar 150mm F4 (early) - 6 Blades
Tele-Takumar 300mm F6.3 - 12 Blades

SMC Pentax-6x7 120mm F3.5 SOFT - 8 Blades

[Adam]

I can do Super Tak 35/2 - but I'll have to figure out which version I have

The one we're missing has a 67mm filter thread.

[Adam]

M37 Takumar 83 F1.9 has 20 blades

I wonder if this design was carried over to the M42 variant!

[Adam]

Thanks @Odinz @jatrax @Aggie89 @marcusBMG @lytrytyr @GUB @alvane @monochrome and @G and T;

I've added the info contributed so far to the database, so all tables should now reflect your data.

If you'd also like to contribute a photo of your lens, please visit this thread for more info:
https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/319706-help...ns-photos.html

[Fcsnt54]

Might be an odd question but how do you check how many blades does a lens have? particularly the 645 ls lenses




---------- Post added 04-27-16 at 07:51 PM ----------

Nevermind just found out. 645 ls 135mm is 5 blades and 645 ls 75mm is 5 blades as well

[Adam]

Might be an odd question but how do you check how many blades does a lens have? particularly the 645 ls lenses

For anyone else stopping by this thread, select the smallest aperture on the aperture ring, then dismount the lens, and finally use your finger to pull down on the aperture lever on the back of the lens. Vary the pressure on the lever until the aperture is big enough to be easily seen.

Another way is to take a long exposure (say 10 seconds) at a stopped-down aperture setting, then look through the front of the lens.

Nevermind just found out. 645 ls 135mm is 5 blades and 645 ls 75mm is 5 blades as well

Thanks! An interesting observation is that all LS lenses seem to only have 5 blades.