Pentax 67: 90mm f/2.8 or 105mm f/2.4?

[Simon DeSantis]

I'm looking ahead to compliment the two lenses I have for my 67 (55mm and 200mm both f/4) with something in the middle. Both the 90mm and 105mm lenses fall right between the two I have and they're both about as fast as you can get. The 105mm is rather cheaper on KEH for a late model (but the same price as an earlier model 90mm). I'm tempted by the 105mm simply because it's half a stop faster but I worry that it might be garbage wide open. However the 105mm is over 100g* heavier and has a minimum focus of 1m compared to the 90mm's 65cm. Any guidance or experience you share would be much appreciated! Thank you.

*though honestly 100g is very little compared to the rest of the camera.

[ErikKaffehr]

Hi,

I have the 90/2.8 and I would say it's more like OK than excellent. It's perfectly good for great images on film, but I see significant weakness in scanned film.

I have done a lot of testing using that lens, like this: http://echophoto.dnsalias.net/ekr/index.php/photoarticles/59-sony-alpha-900-vs-67-analogue-round-2?showall=1

The impression I have is that the 105/2.5 may be marginally better.

Best regards
Erik

[Codger]

I've used the 90 mm for about eight years and have been satisfied with it.  I used the 105 mm a weekend last fall and thought it was similarly sound.  I do landscape and everything is from a sturdy tripod, so I'm not so concerned whether it's f2.8 or f2.4 --  speed is secondary to image quality and field of view.  If I were choosing a lens to complement your kit, I personally would hunt down the 100 mm f4.  It's a fine piece of glass (one of the more recent designs from Pentax) and adds macro capability.  They're in short supply for a reason: they satisfy several needs for different kinds of image work.  Yes, the 100 isn't fast or light, and it will cost more to acquire, but you should at least research it and see if it would add versatility and serve you better than either of the two you mentioned. 

[Simon DeSantis]

Thanks for the suggestion. The 100mm macro is attractive but the price is an issue.
How fiddly is the accessory 1:1 lens to use in practice? I use my 67 almost exclusively outdoors.

[RawheaD]

105/2.4 is not good.


It is MAGICAL.

http://www.flickr.com/search/?q=105mm+pentax&w=88929764%40N00&s=int

[KevinA]

Erik your testing of DR comparing digital  with film is different from any tests or practical results I have found.
I scan with a Coolscan 8000 and make 48bit dng scans, I could easily expose for shadows with film and recover highlights, plus all the colours stayed fairly true with a bit of post.
Digital gives me very little room to exposure for shadow detail, I tested on a very flat day. If it had been a sunny day I don't think you have any choice but to let the shadows go. Any attempt to allow for shadows does not just blow the highlights it messes with colours tones etc not many stops above mid grey.
http://treewithoutabird.com/untitled-2.html

Cheers,

Kevin.

[Simon DeSantis]

Thank you! Your pictures are a good argument in favor of the 105/2.4!

[tsjanik]

Rawhead's photos are a convincing case for the 105, but the 90 is my choice.  It's small, light, close-focusing and has really nice rendering.  It is also quite sharp stopped down. 

Tom
645D,  90mm @f/2.8

[ErikKaffehr]

Hi,

I have made several tests, so I don't know which tests you refer to. Most of my testing was done with Vuescan on the Minolta Dimage Scan Multi Pro, but two test were scanned at a scanning service in Germany using a high end drum scanner at 6096 PPI.

In my experience, correctly exposed digital images have incredible amount of info in the shadows. It's more like the high end that may be problematic.

I mostly shot Velvia in my film days, and I have never really worked with negative film. The reason I tested with negative film was mostly to find out if that would be workable for me.

My tests were done with Ektar 100. One trouble I may have ran into could be that one of the channels my have exceeded the dynamic range of my scanner. It is specified at 4.8 but it's a gross overestimate for sure.

The digital camera I used is a Sony Alpha 900, always at 100 ISO and generally striving for ETTR. Processing is done in Lightroom, naturally from "raw".

Lets put it this way. I have done a lot of testing (around 10 rolls of 120 film just for testing), and I have done the findings I have. Very possible that a better scanner or scanning program may produce better images.

I have been shooting MF and Velvia for around 10 years, before migrating to digital, and I have been scanning film for something like 15 years using differeent kinds of CCD scanners, so I'm not without experience.

Best regards
Erik 

Erik your testing of DR comparing digital  with film is different from any tests or practical results I have found.
I scan with a Coolscan 8000 and make 48bit dng scans, I could easily expose for shadows with film and recover highlights, plus all the colours stayed fairly true with a bit of post.
Digital gives me very little room to exposure for shadow detail, I tested on a very flat day. If it had been a sunny day I don't think you have any choice but to let the shadows go. Any attempt to allow for shadows does not just blow the highlights it messes with colours tones etc not many stops above mid grey.
http://treewithoutabird.com/untitled-2.html

Cheers,

Kevin.

[KevinA]

Hi,

I have made several tests, so I don't know which tests you refer to. Most of my testing was done with Vuescan on the Minolta Dimage Scan Multi Pro, but two test were scanned at a scanning service in Germany using a high end drum scanner at 6096 PPI.

In my experience, correctly exposed digital images have incredible amount of info in the shadows. It's more like the high end that may be problematic.

I mostly shot Velvia in my film days, and I have never really worked with negative film. The reason I tested with negative film was mostly to find out if that would be workable for me.

My tests were done with Ektar 100. One trouble I may have ran into could be that one of the channels my have exceeded the dynamic range of my scanner. It is specified at 4.8 but it's a gross overestimate for sure.

The digital camera I used is a Sony Alpha 900, always at 100 ISO and generally striving for ETTR. Processing is done in Lightroom, naturally from "raw".

Lets put it this way. I have done a lot of testing (around 10 rolls of 120 film just for testing), and I have done the findings I have. Very possible that a better scanner or scanning program may produce better images.

I have been shooting MF and Velvia for around 10 years, before migrating to digital, and I have been scanning film for something like 15 years using differeent kinds of CCD scanners, so I'm not without experience.

Best regards
Erik 

I was not trying to undermine you or your opinion. Shooting Velvia would make it a close call.
What I find with colour neg is you can expose well into the shadows and retain highlight detail. Digital has to be exposed for the highlights. I find digging into digital shadows not very rewarding.
I don't find colour neg has a lot of shadow detail either if you expose for mid grey. What it does have though is the ability to expose for shadows and retain incredible highlight detail. I scan at 48bit dng on a Coolscan, the DR is jaw droppingly good.

Regards,

Kevin.

[rgs]

I have a 55 and a 105. The majority of the 6x7 images on my website (http://www.myrsphoto.com/Galleries/album/index.html) were shot with the 105. It's a good lens and slightly long for the format which I like. I have also shot many weddings with the 67 and the 105 without changing lenses. The only problem is the very loud shutter of the 67!

I'm planning on selling the 67 for either a used 50D or 7D but it won't be easy to part with. It's been a trusted friend for many years.

[rgs]

What I find with colour neg is you can expose well into the shadows and retain highlight detail. Digital has to be exposed for the highlights. I find digging into digital shadows not very rewarding.
I don't find colour neg has a lot of shadow detail either if you expose for mid grey. What it does have though is the ability to expose for shadows and retain incredible highlight detail. I scan at 48bit dng on a Coolscan, the DR is jaw droppingly good.

I always used Velvia for chrome and Fujicolor NPS or NHS for color neg. Very few yellow boxes. My negs were bulletproof for may years and printed beautifully just as you say until the digital printers showed up and couldn't handle the density. I kept getting nasty notes from my labs. I miss film's gentle shouldering out instead of going over the digital cliff!

[Simon DeSantis]

I have a friend I sometimes tease for favoring very narrow DoF in his photos. I was showing off to him the narrow DoF effect I could get at f/5.6 and f/4 with my 67 system and I showed him the flickr photos you linked as an example of what an even faster lens can achieve.

Now the man who shoots 100-200 frames on a 5DmkII in machine gun mode while I take 10-20 frames on the same outing says he wants to go medium format!

[Codger]

It's a good thing when a light bulb goes on.  More power to him, and to you.  Have you acquired your lens yet?

[Simon DeSantis]

I have not acquired either lens yet. Unfortunately car repairs are taking budget priority for the foreseeable future...