Problem focussing Samyang 85mm F1.4

Wasp · 07-28-2021, 10:33 AM

I have two of these lenses (in different mounts, my GAS is pretty bad). My own experience with wearing glasses and manually focusing it on a DSLR can be summed up in two words : forget it.

Live view with magnification works best.

wadge22 · 07-28-2021, 11:32 AM

Oh no! Don't give up, or forget it entirely. Just because it's hard, doesn't mean you shouldn't keep working at it. It's not impossible. It's a skill you can work at.

Like bowling a strike, or sinking a few free throws in a row, or hitting a target with a (choose your favorite projectile launcher here, I pick suction-cup-bow-and-arrow), or tight parallel parking, or dividing a lump of dough into five equal-weight pieces. Or a thousand other cool human tricks.

It seems almost impossible to control everything involved at first. There will have to be a little 'luck' or 'magic' involved with some of the early successes. But as you keep at it, and keep evaluating your hits AND your misses, your brain and your muscle memory will start to become a little more magical. You will get a little more lucky, a little more often. By the time you're halfway decent, you will realize that the luck and the magic are really 'skill,' after all.
And you'll still need lots more practice

Also, you will probably never get even close to %100 hit rate. That's OK.

---------------

If your DOF is so thin you can't focus well, you can stop down. Voila... built in training wheels.
Pretend it's an 85 f2.8 for a while, until you're good at focusing that. Then start going to f2.0, another level of difficulty.

Finally, I would read up on catch in focus and focus confirmation, two of the options Pentax built into your camera to help with exactly this problem. I don't rely on either of those tools myself when shooting manual focus. Some people do.
Your lens, your camera, your eyes, your touch, your shot selection, YMMV.

**othar** · 07-28-2021, 12:12 PM - **1 Like**

Originally posted by wadge22

If your DOF is so thin you can't focus well, you can stop down. Voila... built in training wheels.

Love it

**Sakura** · 07-28-2021, 01:09 PM

Originally posted by jatrax

Calibrating the lens using the AF fine tuning only calibrates the AF acknowledgement of an in focus situation. When manually focusing with the viewfinder the diopter is what needs to be adjusted.

Calibrating the Diopter of Your Camera | B&H Explora (bhphotovideo.com)?

Wear Glasses? How to Easily Calibrate Your Camera's Diopter (industrydev.com)

Lot off not needed trouble.
It is much much more easy. Just look at the information projected in the viewfinder. If you see that sharp, you're diopter is perfectly calibrated for you're eyes.

---------- Post added 07-28-2021 at 10:14 PM ----------

Originally posted by Wasp

I have two of these lenses (in different mounts, my GAS is pretty bad). My own experience with wearing glasses and manually focusing it on a DSLR can be summed up in two words : forget it.

Live view with magnification works best.

I had the same experience, UNTIL i bought the K1-II. With that viewfinder i was finally able to manual focus again (couldn't do it anymore since the MX)

At my former K7 i even added an extra -2 diopter to compensate for not wearing my glasses when trying to manual focus. But i still couldn't.

wadge22 · 07-28-2021, 01:32 PM

Originally posted by Sakura

Lot off not needed trouble.It is much much more easy. Just look at the information projected in the viewfinder. If you see that sharp, you're diopter is perfectly calibrated for you're eyes.

That's my understanding too. Just adjust the diopter till the black lines are focused for you, whether wearing your glasses or not (I wear specs but not a strong rx). Right?

**Lowell Goudge** · 07-28-2021, 03:12 PM

Not sure anyone has mentioned this yet, but the viewfinder of a DSLR cannot resolve differences in focus for lenses faster than about F4-5.6 because that is what the kit lens is. As a result, unless you go for a split image finder, or calibrate the focus indicator to show focus when in focus, you will always have issues. I have the Sam yang 85/1.4 also and use it with a diagonal split image finder bought about 10 years ago.

To calibrate for manual lenses, you need to use the option for AF adjustment that adjusts all, since MF lenses don’t have a means to communicate what they are to the camera

However once calibrated, you still need to make sure you have adjusted the viewfinder diopter for your eyesight

peggers · 07-28-2021, 04:47 PM

Thank you all for your excellent and well considered suggestions. I will make a note of each and gradually work my way through them. In the meantime I have found 2 things do work reasonably well. Firstly, forgetting about F1.4 and thinking of the lens as an F2.8 lens. At this point focus is much more reliable and photos are much sharper. Bokeh is also quite good too. The other thing that helps is having the focus beep turned on. Annoying? Yes, most definitely.

wadge22 · 07-28-2021, 07:00 PM - **1 Like**

Oh yes, I know I've replied plenty to this thread already, but one more thing I haven't seen anyone mention here:

Eyepiece O-ME53

It slips right on to your camera, and makes everything in the viewfinder a little clearer and larger. It's just the right magnification that you can still (just barely) see all the info at the bottom of the viewfinder. Mine rarely leaves my K1.
I got it for under US$50 brand new. If that's not a ton of money to you, I definitely recommend picking one up. It won't solve your problem entirely, but will help a little and I see no downside other than spending a bit more money.

**UncleVanya** · 07-28-2021, 08:52 PM

Originally posted by Lowell Goudge

To calibrate for manual lenses, you need to use the option for AF adjustment that adjusts all, since MF lenses don’t have a means to communicate what they are to the camera.

My impression is that some manual focus lenses do talk to the camera. Maybe Irix?

peggers · 07-28-2021, 09:20 PM

Originally posted by Lowell Goudge

Not sure anyone has mentioned this yet, but the viewfinder of a DSLR cannot resolve differences in focus for lenses faster than about F4-5.6 because that is what the kit lens is. As a result, unless you go for a split image finder, or calibrate the focus indicator to show focus when in focus, you will always have issues. I have the Sam yang 85/1.4 also and use it with a diagonal split image finder bought about 10 years ago.

To calibrate for manual lenses, you need to use the option for AF adjustment that adjusts all, since MF lenses don’t have a means to communicate what they are to the camera

However once calibrated, you still need to make sure you have adjusted the viewfinder diopter for your eyesight

So the follow on question to that is, where do I get a split image finder for my K1? I do recall that for my old ME Super the split image focussing was always deadly accurate

wadge22 · 07-28-2021, 09:42 PM

Here are two relevant threads:

Commercially available option

DIY option using available Canon screen

I have used both, and had generally good experiences with both. I can elaborate if you'd like, but I'm feeling a bit like I've been long winded in this thread, so I'll only chime in any further upon request.

**UncleVanya** · 07-29-2021, 06:54 AM

Originally posted by peggers

So the follow on question to that is, where do I get a split image finder for my K1? I do recall that for my old ME Super the split image focussing was always deadly accurate

Just be aware that:
1)calibrating the screen (via shims) may be needed.
2) metering may be impacted - particularly spot metering.

**davidreilly3207** · 07-29-2021, 05:07 PM

Originally posted by othar

My eyesight is slightly varying so I have to check my diopter adjustment at the beginning of every photo session, when I plan to use manual focus lenses (focus with LV -> switch to OVF and turn diopter adjustment till the same area is in focus). After that I get more accurate focus (for wide apertures) than with the focus confirmation point in the OVF, because the focus confirmation of my K-3 is only accurate for f2.8 lenses (or slower), I don't know for what apertures the PDAF of the K-1 will be accurate though.

You should not adjust diopter using the subject of photo. Adjust the diopter so that the written info, shutter speed, stop, etc., displayed is in focus.

**othar** · 07-30-2021, 12:12 AM

Originally posted by davidreilly3207

You should not adjust diopter using the subject of photo. Adjust the diopter so that the written info, shutter speed, stop, etc., displayed is in focus.

Why not, I get accurate focus afterwards?

Ishpuini · 07-30-2021, 12:32 AM

IMHO, the only reliable way is LiveView indeed. Even with the much improved OVF in the K-3III I'm having trouble focusing some of my manual lenses, esp wide open. For most I more or less know the stopped down aperture where increased depth-of-field starts to cover for the missed focus sufficiently. Of course that means the ability to focus manually thourgh the OVF is related to the focal length. The Samyang 16/2 will be OK wide open, the Samyang 24/1.4 needs to be stopped down to at least f/2.8, on the Pentax K50/1.2 it's f/4, etc... For a 85mm lens, I imagine even f/8 might be hard pressed. I know I always use LiveView on my Samyang 135/2.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Pentax DFA* 85mm F1.4 versus Zeiss Otus 85mm F1.4 shootout	beholder3	Pentax SLR Lens Discussion	4	07-23-2020 10:37 AM
Sigma 85mm f1.4 or FA 77mm f1.8 or just wait for DFA 85mm f1.4	cataseven	Pentax SLR Lens Discussion	22	04-25-2017 06:05 PM
For Sale - Sold: Samyang - Rokinon 85mm f1.4 and Pentax-m 50mm f1.4	cali92rs	Sold Items	6	01-31-2014 12:10 PM
How can I check if my Tamron 17-50 is front-focussing/back-focussing and needs repair	photoleet	Pentax SLR Lens Discussion	6	03-31-2013 03:58 PM
For Sale - Sold: a Bevy of 85mm lenses: pentax-m 85mm f2k and Rokinon 85mm f1.4	gscara	Sold Items	3	06-07-2011 07:56 PM

07-28-2021, 10:33 AM	#16
Wasp Pentaxian Join Date: Mar 2017 Location: Pretoria Photos: Gallery Posts: 4,661	I have two of these lenses (in different mounts, my GAS is pretty bad). My own experience with wearing glasses and manually focusing it on a DSLR can be summed up in two words : forget it. Live view with magnification works best.

07-28-2021, 11:32 AM	#17
wadge22 Veteran Member Join Date: Jun 2021 Location: NE Ohio Photos: Albums Posts: 897	Oh no! Don't give up, or forget it entirely. Just because it's hard, doesn't mean you shouldn't keep working at it. It's not impossible. It's a skill you can work at. Like bowling a strike, or sinking a few free throws in a row, or hitting a target with a (choose your favorite projectile launcher here, I pick suction-cup-bow-and-arrow), or tight parallel parking, or dividing a lump of dough into five equal-weight pieces. Or a thousand other cool human tricks. It seems almost impossible to control everything involved at first. There will have to be a little 'luck' or 'magic' involved with some of the early successes. But as you keep at it, and keep evaluating your hits AND your misses, your brain and your muscle memory will start to become a little more magical. You will get a little more lucky, a little more often. By the time you're halfway decent, you will realize that the luck and the magic are really 'skill,' after all. And you'll still need lots more practice Also, you will probably never get even close to %100 hit rate. That's OK. --------------- If your DOF is so thin you can't focus well, you can stop down. Voila... built in training wheels. Pretend it's an 85 f2.8 for a while, until you're good at focusing that. Then start going to f2.0, another level of difficulty. Finally, I would read up on catch in focus and focus confirmation, two of the options Pentax built into your camera to help with exactly this problem. I don't rely on either of those tools myself when shooting manual focus. Some people do. Your lens, your camera, your eyes, your touch, your shot selection, YMMV.

07-28-2021, 12:12 PM - 1 Like	#18
othar Site Supporter Join Date: May 2014 Location: Linz Photos: Albums Posts: 3,098	Originally posted by wadge22 If your DOF is so thin you can't focus well, you can stop down. Voila... built in training wheels. Love it

07-28-2021, 01:09 PM	#19
Sakura Site Supporter Join Date: Jan 2010 Location: Netherlands Photos: Gallery Posts: 438	Originally posted by jatrax Calibrating the lens using the AF fine tuning only calibrates the AF acknowledgement of an in focus situation. When manually focusing with the viewfinder the diopter is what needs to be adjusted. Calibrating the Diopter of Your Camera \| B&H Explora (bhphotovideo.com)? Wear Glasses? How to Easily Calibrate Your Camera's Diopter (industrydev.com) Lot off not needed trouble. It is much much more easy. Just look at the information projected in the viewfinder. If you see that sharp, you're diopter is perfectly calibrated for you're eyes. ---------- Post added 07-28-2021 at 10:14 PM ---------- Originally posted by Wasp I have two of these lenses (in different mounts, my GAS is pretty bad). My own experience with wearing glasses and manually focusing it on a DSLR can be summed up in two words : forget it. Live view with magnification works best. I had the same experience, UNTIL i bought the K1-II. With that viewfinder i was finally able to manual focus again (couldn't do it anymore since the MX) At my former K7 i even added an extra -2 diopter to compensate for not wearing my glasses when trying to manual focus. But i still couldn't.

07-28-2021, 01:32 PM	#20
wadge22 Veteran Member Join Date: Jun 2021 Location: NE Ohio Photos: Albums Posts: 897	Originally posted by Sakura Lot off not needed trouble.It is much much more easy. Just look at the information projected in the viewfinder. If you see that sharp, you're diopter is perfectly calibrated for you're eyes. That's my understanding too. Just adjust the diopter till the black lines are focused for you, whether wearing your glasses or not (I wear specs but not a strong rx). Right?

07-28-2021, 03:12 PM	#21
Lowell Goudge Site Supporter Join Date: Jan 2007 Location: Toronto Photos: Gallery \| Albums Posts: 17,888	Not sure anyone has mentioned this yet, but the viewfinder of a DSLR cannot resolve differences in focus for lenses faster than about F4-5.6 because that is what the kit lens is. As a result, unless you go for a split image finder, or calibrate the focus indicator to show focus when in focus, you will always have issues. I have the Sam yang 85/1.4 also and use it with a diagonal split image finder bought about 10 years ago. To calibrate for manual lenses, you need to use the option for AF adjustment that adjusts all, since MF lenses don’t have a means to communicate what they are to the camera However once calibrated, you still need to make sure you have adjusted the viewfinder diopter for your eyesight

07-28-2021, 04:47 PM	#22
peggers Senior Member Join Date: Apr 2012 Location: Endeavour Hills, Victoria, Australia Photos: Gallery Posts: 210 Original Poster	Thank you all for your excellent and well considered suggestions. I will make a note of each and gradually work my way through them. In the meantime I have found 2 things do work reasonably well. Firstly, forgetting about F1.4 and thinking of the lens as an F2.8 lens. At this point focus is much more reliable and photos are much sharper. Bokeh is also quite good too. The other thing that helps is having the focus beep turned on. Annoying? Yes, most definitely.

07-28-2021, 07:00 PM - 1 Like	#23
wadge22 Veteran Member Join Date: Jun 2021 Location: NE Ohio Photos: Albums Posts: 897	Oh yes, I know I've replied plenty to this thread already, but one more thing I haven't seen anyone mention here: Eyepiece O-ME53 It slips right on to your camera, and makes everything in the viewfinder a little clearer and larger. It's just the right magnification that you can still (just barely) see all the info at the bottom of the viewfinder. Mine rarely leaves my K1. I got it for under US$50 brand new. If that's not a ton of money to you, I definitely recommend picking one up. It won't solve your problem entirely, but will help a little and I see no downside other than spending a bit more money.

07-28-2021, 08:52 PM	#24
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,404	Originally posted by Lowell Goudge To calibrate for manual lenses, you need to use the option for AF adjustment that adjusts all, since MF lenses don’t have a means to communicate what they are to the camera. My impression is that some manual focus lenses do talk to the camera. Maybe Irix?

07-28-2021, 09:20 PM	#25
peggers Senior Member Join Date: Apr 2012 Location: Endeavour Hills, Victoria, Australia Photos: Gallery Posts: 210 Original Poster	Originally posted by Lowell Goudge Not sure anyone has mentioned this yet, but the viewfinder of a DSLR cannot resolve differences in focus for lenses faster than about F4-5.6 because that is what the kit lens is. As a result, unless you go for a split image finder, or calibrate the focus indicator to show focus when in focus, you will always have issues. I have the Sam yang 85/1.4 also and use it with a diagonal split image finder bought about 10 years ago. To calibrate for manual lenses, you need to use the option for AF adjustment that adjusts all, since MF lenses don’t have a means to communicate what they are to the camera However once calibrated, you still need to make sure you have adjusted the viewfinder diopter for your eyesight So the follow on question to that is, where do I get a split image finder for my K1? I do recall that for my old ME Super the split image focussing was always deadly accurate

07-28-2021, 09:42 PM	#26
wadge22 Veteran Member Join Date: Jun 2021 Location: NE Ohio Photos: Albums Posts: 897	Here are two relevant threads: Commercially available option DIY option using available Canon screen I have used both, and had generally good experiences with both. I can elaborate if you'd like, but I'm feeling a bit like I've been long winded in this thread, so I'll only chime in any further upon request.

07-29-2021, 06:54 AM	#27
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,404	Originally posted by peggers So the follow on question to that is, where do I get a split image finder for my K1? I do recall that for my old ME Super the split image focussing was always deadly accurate Just be aware that: 1)calibrating the screen (via shims) may be needed. 2) metering may be impacted - particularly spot metering.

07-29-2021, 05:07 PM	#28
davidreilly3207 Loyal Site Supporter Join Date: Sep 2009 Location: South Jersey Photos: Gallery \| Albums Posts: 720	Originally posted by othar My eyesight is slightly varying so I have to check my diopter adjustment at the beginning of every photo session, when I plan to use manual focus lenses (focus with LV -> switch to OVF and turn diopter adjustment till the same area is in focus). After that I get more accurate focus (for wide apertures) than with the focus confirmation point in the OVF, because the focus confirmation of my K-3 is only accurate for f2.8 lenses (or slower), I don't know for what apertures the PDAF of the K-1 will be accurate though. You should not adjust diopter using the subject of photo. Adjust the diopter so that the written info, shutter speed, stop, etc., displayed is in focus.

07-30-2021, 12:12 AM	#29
othar Site Supporter Join Date: May 2014 Location: Linz Photos: Albums Posts: 3,098	Originally posted by davidreilly3207 You should not adjust diopter using the subject of photo. Adjust the diopter so that the written info, shutter speed, stop, etc., displayed is in focus. Why not, I get accurate focus afterwards?

07-30-2021, 12:32 AM	#30
Ishpuini Veteran Member Join Date: Sep 2006 Location: Antwerp, Belgium Photos: Gallery Posts: 1,727	IMHO, the only reliable way is LiveView indeed. Even with the much improved OVF in the K-3III I'm having trouble focusing some of my manual lenses, esp wide open. For most I more or less know the stopped down aperture where increased depth-of-field starts to cover for the missed focus sufficiently. Of course that means the ability to focus manually thourgh the OVF is related to the focal length. The Samyang 16/2 will be OK wide open, the Samyang 24/1.4 needs to be stopped down to at least f/2.8, on the Pentax K50/1.2 it's f/4, etc... For a 85mm lens, I imagine even f/8 might be hard pressed. I know I always use LiveView on my Samyang 135/2.