105/2.4 or 90/2.8 (late) for 6x7 landscape work?

desertscape · 11-12-2016, 04:05 PM

I had considered using the 120, as you have said, for landscapes. I use the 120mm setting on my zoom quite a bit, so it is a useful focal length. Never did buy a 120 though. From what I remember, Pentax left spherical aberration uncorrected to give it softness.

Paul MaudDib · 12-18-2016, 10:56 PM

I say go with the 105/2.4 just because it's a little faster, but it's really up to you. Your normal lens isn't usually the go-to for landscapes anyway, so I don't think it makes a huge difference either way.

Originally posted by CreationBear

Apologies to Colton for a semi-hijack of the thread, but I'm curious: where does the 100/4 macro fit in the mix? In my still-hypothetical three lens kit, the 77mm option seems to have a lot going for it, with the 55/4, the 100/4, and the 200/4. Do you think having a faster lens as a fall-back for lowlight focusing would outweigh the economy of shared filters/hoods/etc.?

I would say to prefer the 90/2.8 or 105/2.4 just because they are optimized for near-infinity work. The 135mm Macro has some issues with near-infinity work, and the 100mm macro probably isn't its best near infinity either.

If you want to share filters, buy filters for your largest lens and step-up adapter rings for each smaller filter size. I use 77mm as standard, but this does mean that I can't use my filters on my 75mm f/4.5.

tuco · 01-05-2017, 12:01 PM - **1 Like**

I have both the 105mm and 90mm and will use either one. The 90mm gets a little more near/far in focus for a given aperture of course.

Some 90mm examples I've posted before. Both focused using the DOF scale on the lens.

CreationBear · 01-05-2017, 05:28 PM

Originally posted by tuco

Both focused using the DOF scale on the lens

Nice shots, Tuco--you must have really been cranked down on the last one.

Again, apologies to the OP, but I'm curious about your technique getting hyperfocal distances assuming you don't carry a chart (or smartphone app, I suppose). For the first, I'd be tempted to "measure" the distance to the foreground rock and double it for the hyperfocal distance, but perhaps you feel the need for a more precise approach with a 6x7?

Silent Street · 01-05-2017, 07:07 PM

Originally posted by CreationBear

Again, apologies to the OP, but I'm curious about your technique getting hyperfocal distances assuming you don't carry a chart (or smartphone app, I suppose). For the first, I'd be tempted to "measure" the distance to the foreground rock and double it for the hyperfocal distance, but perhaps you feel the need for a more precise approach with a 6x7?

The scales on each lens are there for a good purpose — for the determination of hyperfocal at any given aperture between minimum and maximum. There is no need for apps, gizmos, charts and PhDs to apply HF effectively. Remember that wider f/lengths e.g. 45mm, have inherently greater depth of field and setting HF is very easy. As the f/length increases, familiarisation of that lens's HF characteristics becomes important. Of course, you can always stop down to f22, but that isn't the best thing to do in the landscape context.

CreationBear · 01-06-2017, 06:19 AM

Originally posted by Silent Street

There is no need for apps, gizmos, charts and PhDs

Ha, as I'm still using an early 'aughts flip-phone, that's good to know.

At any rate, I've read that the scales on some of these lenses are a bit optimistic in terms of DOF, but nothing a little Kentucky windage won't fix.

tuco · 01-06-2017, 06:50 AM

Originally posted by CreationBear

Nice shots, Tuco--you must have really been cranked down on the last one.

Thanks. Yes, it was stopped down to f19. The DOF scale on lenses varies on how accurate it is for hyperfocal. But after a little trial and error you can get by just fine.

Swift1 · 01-11-2017, 11:10 PM - **1 Like**

Originally posted by tuco

I have both the 105mm and 90mm and will use either one. The 90mm gets a little more near/far in focus for a given aperture of course.

Some 90mm examples I've posted before. Both focused using the DOF scale on the lens.

I ended up just bringing both on my trip. Even though they are close in focal length, they're both different and it's nice to have both.

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11-12-2016, 04:05 PM	#31
desertscape Pentaxian Join Date: Feb 2009 Location: Arizona Posts: 1,272	I had considered using the 120, as you have said, for landscapes. I use the 120mm setting on my zoom quite a bit, so it is a useful focal length. Never did buy a 120 though. From what I remember, Pentax left spherical aberration uncorrected to give it softness.

12-18-2016, 10:56 PM	#32
Paul MaudDib Senior Member Join Date: Jul 2009 Location: Michigan Posts: 294	I say go with the 105/2.4 just because it's a little faster, but it's really up to you. Your normal lens isn't usually the go-to for landscapes anyway, so I don't think it makes a huge difference either way. Originally posted by CreationBear Apologies to Colton for a semi-hijack of the thread, but I'm curious: where does the 100/4 macro fit in the mix? In my still-hypothetical three lens kit, the 77mm option seems to have a lot going for it, with the 55/4, the 100/4, and the 200/4. Do you think having a faster lens as a fall-back for lowlight focusing would outweigh the economy of shared filters/hoods/etc.? I would say to prefer the 90/2.8 or 105/2.4 just because they are optimized for near-infinity work. The 135mm Macro has some issues with near-infinity work, and the 100mm macro probably isn't its best near infinity either. If you want to share filters, buy filters for your largest lens and step-up adapter rings for each smaller filter size. I use 77mm as standard, but this does mean that I can't use my filters on my 75mm f/4.5.

01-05-2017, 12:01 PM - 1 Like	#33
tuco Pentaxian Join Date: Jul 2009 Location: Pugetopolis Posts: 11,026	I have both the 105mm and 90mm and will use either one. The 90mm gets a little more near/far in focus for a given aperture of course. Some 90mm examples I've posted before. Both focused using the DOF scale on the lens.

01-05-2017, 05:28 PM	#34
CreationBear Veteran Member Join Date: Aug 2013 Posts: 2,415	Originally posted by tuco Both focused using the DOF scale on the lens Nice shots, Tuco--you must have really been cranked down on the last one. Again, apologies to the OP, but I'm curious about your technique getting hyperfocal distances assuming you don't carry a chart (or smartphone app, I suppose). For the first, I'd be tempted to "measure" the distance to the foreground rock and double it for the hyperfocal distance, but perhaps you feel the need for a more precise approach with a 6x7?

01-05-2017, 07:07 PM	#35
Silent Street Veteran Member Join Date: Nov 2011 Location: Castlemaine, Victoria, AUS Photos: Albums Posts: 1,151	Originally posted by CreationBear Again, apologies to the OP, but I'm curious about your technique getting hyperfocal distances assuming you don't carry a chart (or smartphone app, I suppose). For the first, I'd be tempted to "measure" the distance to the foreground rock and double it for the hyperfocal distance, but perhaps you feel the need for a more precise approach with a 6x7? The scales on each lens are there for a good purpose — for the determination of hyperfocal at any given aperture between minimum and maximum. There is no need for apps, gizmos, charts and PhDs to apply HF effectively. Remember that wider f/lengths e.g. 45mm, have inherently greater depth of field and setting HF is very easy. As the f/length increases, familiarisation of that lens's HF characteristics becomes important. Of course, you can always stop down to f22, but that isn't the best thing to do in the landscape context.

01-06-2017, 06:19 AM	#36
CreationBear Veteran Member Join Date: Aug 2013 Posts: 2,415	Originally posted by Silent Street There is no need for apps, gizmos, charts and PhDs Ha, as I'm still using an early 'aughts flip-phone, that's good to know. At any rate, I've read that the scales on some of these lenses are a bit optimistic in terms of DOF, but nothing a little Kentucky windage won't fix.

01-06-2017, 06:50 AM	#37
tuco Pentaxian Join Date: Jul 2009 Location: Pugetopolis Posts: 11,026	Originally posted by CreationBear Nice shots, Tuco--you must have really been cranked down on the last one. Thanks. Yes, it was stopped down to f19. The DOF scale on lenses varies on how accurate it is for hyperfocal. But after a little trial and error you can get by just fine.

01-11-2017, 11:10 PM - 1 Like	#38
Swift1 Veteran Member Join Date: Sep 2009 Location: Oregon Photos: Gallery \| Albums Posts: 5,079 Original Poster	Originally posted by tuco I have both the 105mm and 90mm and will use either one. The 90mm gets a little more near/far in focus for a given aperture of course. Some 90mm examples I've posted before. Both focused using the DOF scale on the lens. I ended up just bringing both on my trip. Even though they are close in focal length, they're both different and it's nice to have both.