Which 45mm for 645?

LightMeter · 10-20-2011, 06:51 AM

I want to get a wide angle lens and debating between the Pentax 45 2.8 SMC A or the Mir-26b 45 3.5. The Mir is less expensive, but cost will be about the same considering I need to buy a Pentacon 6-645 adapter(about 50-60usd on ebay). From research I've done, the Mir is flare prone and has some barrel distortion. How's the Pentax with flare and distortion? The Pentax definitely has an advantage on filter size-67mm versus 82. The Pentax is about 2/3 stop faster on max aperture, but it's not an issue. The Mir has a huge advantage to me because I can use it with my Pentacon 6-Nikon tilt adapter. And I'd consider the Mir more of a collectible. What's your opinion?

**blackcloudbrew** · 10-20-2011, 07:29 AM

I can't speak to flare resistance on the 645 A 45 but it doesn't have a lot of distortion. Here is a link to my flickr site with some images shot with my 45 mm lens. Note that some of them may not be from the 45 as my record keeping isn't always spot on (I could have used the 55mm) but most of them are from the 45.

Flickr: blackcloudbrew's stuff tagged with 64545

By my estimation the 645 A 45mm is equivalent to about a 28mm on a 35mm camera. So it should not be so wide that you get a lot of distortion.

stevebrot · 10-20-2011, 01:28 PM

Here is a link to two of mine taken with the FA 45/2.8:

Flickr: fotostevia's stuff tagged with pentaxfa4528

My experience is that the lens is sharp, has low distortion, and great build. I would expect similar from the A version.

LightMeter · 10-21-2011, 10:02 AM

Nice images! I'm sure the Pentax 45 is a fine lens. I'm still undecided, but there's no hurry.

LightMeter · 10-27-2011, 07:55 PM

I decided on a Mir 26B. Bought it from someone on the MF lens forums. Looking forward to shooting with it, but will probably take at least 2 weeks from Italy. But I won't be able to use it on the 645 until i find a Pentacon 6-645 adapter and it gets here. Hope it's all here by Thanksgiving weekend for my trip.

wkkato · 10-28-2011, 12:56 PM

I have both the Harblei (same glass inside as the Mir I think) as well as the Pentax 45mm. I haven't compared them side by side but the 45mm from Pentax isn't the sharpest Pentax lens although entirely usable. It probably my most used focal length.

My Hartblei has to be stopped down to f11 or f16 for best sharpness.

Warren

10-20-2011, 06:51 AM	#1
LightMeter Senior Member Join Date: Sep 2011 Location: Houston, Republic of Texas Posts: 158	Which 45mm for 645? I want to get a wide angle lens and debating between the Pentax 45 2.8 SMC A or the Mir-26b 45 3.5. The Mir is less expensive, but cost will be about the same considering I need to buy a Pentacon 6-645 adapter(about 50-60usd on ebay). From research I've done, the Mir is flare prone and has some barrel distortion. How's the Pentax with flare and distortion? The Pentax definitely has an advantage on filter size-67mm versus 82. The Pentax is about 2/3 stop faster on max aperture, but it's not an issue. The Mir has a huge advantage to me because I can use it with my Pentacon 6-Nikon tilt adapter. And I'd consider the Mir more of a collectible. What's your opinion?

10-20-2011, 07:29 AM	#2
blackcloudbrew Loyal Site Supporter Join Date: Mar 2009 Location: Cotati, California USA Photos: Gallery \| Albums Posts: 4,460	I can't speak to flare resistance on the 645 A 45 but it doesn't have a lot of distortion. Here is a link to my flickr site with some images shot with my 45 mm lens. Note that some of them may not be from the 45 as my record keeping isn't always spot on (I could have used the 55mm) but most of them are from the 45. Flickr: blackcloudbrew's stuff tagged with 64545 By my estimation the 645 A 45mm is equivalent to about a 28mm on a 35mm camera. So it should not be so wide that you get a lot of distortion. Last edited by blackcloudbrew; 10-20-2011 at 08:08 AM.

10-28-2011, 12:56 PM	#6
wkkato Forum Member Join Date: Sep 2009 Location: Irvine Posts: 53	Which 45mm I have both the Harblei (same glass inside as the Mir I think) as well as the Pentax 45mm. I haven't compared them side by side but the 45mm from Pentax isn't the sharpest Pentax lens although entirely usable. It probably my most used focal length. My Hartblei has to be stopped down to f11 or f16 for best sharpness. Warren

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10-20-2011, 01:28 PM	#3
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Here is a link to two of mine taken with the FA 45/2.8: Flickr: fotostevia's stuff tagged with pentaxfa4528 My experience is that the lens is sharp, has low distortion, and great build. I would expect similar from the A version.

10-21-2011, 10:02 AM	#4
LightMeter Senior Member Join Date: Sep 2011 Location: Houston, Republic of Texas Posts: 158 Original Poster	Nice images! I'm sure the Pentax 45 is a fine lens. I'm still undecided, but there's no hurry.

10-27-2011, 07:55 PM	#5
LightMeter Senior Member Join Date: Sep 2011 Location: Houston, Republic of Texas Posts: 158 Original Poster	I decided on a Mir 26B. Bought it from someone on the MF lens forums. Looking forward to shooting with it, but will probably take at least 2 weeks from Italy. But I won't be able to use it on the 645 until i find a Pentacon 6-645 adapter and it gets here. Hope it's all here by Thanksgiving weekend for my trip.

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