*ist D focus out

GrahamNR17 · Expire: 2012-09-06

Oh balls

I've been taking some pics at full aperture, but the image has been out of focus. So I set it on a tripod with remote release, focussed really carefully, and took pics. The focus point in the resulting image is further away by almost half a metre Evil or Very Mad

Can that be fixed, do you think?

I have zero budget to replace it Confused

Riku · Expire: 2017-04-30

Are you talking about manual or auto focus?

GrahamNR17 · Expire: 2012-09-06

Good point, I missed that vital information out of my message Embarassed

...it is with manual focus lenses. I tested it with my old Helios 44-2 and Industar 50-2.

Spotmatic · Joined: 18 Aug 2008 Posts: 4045 Location: Netherlands

Did you rely on the focus confirmation or did you use the ground glass screen?

GrahamNR17 · Expire: 2012-09-06

I just used the screen. I didn't know there was focus confirm on MF Shocked

...I shall read the manual this evening Embarassed

kuuan · Expire: 2014-12-26

Graham this is manually focusing, yes?
I believe that it must be the focus screen that is not installed properly, and that this should be all that's wrong!

In case of backfocusing, as you describe, you need to put the focus screen further away from the prism, more close to the mirror. Split focus screens come with spacers, but mine did not. I applied layers of thin adhesive tape to the very outer left and right edges of the screen.

The *ist is designed to easily take out and again put in the focus screen, see: http://www.focusingscreen.com/work/k7en.htm
resp. this on 'theory' of correct installation:
http://www.focusingscreen.com/work/test-fsen.htm

hope this helps
Andreas

edit:
oh..I took so long to write my answer, there had been a few answers already.
yes, there is double focus confirmation, one is a peep sound ( which can be turned off ) and the other a green hexagon lighting up in the viewfinder

as mentioned before I believe it just must be the focus screen being badly installed - maybe the prior owner had a split focus screen for manual lenses installed Wink

but before selling the camera had - badly placed - the original back in

GrahamNR17 · Expire: 2012-09-06

Fabulous, thankyou so much. I shall go and get my lights and tweezers and set about checking the screen - then find out how to turn the peep and hexagon on Cool

kuuan · Expire: 2014-12-26

Graham googling I found that various users seemed to have had problems to get the focus confirm on the *istD, others say that it is there, just as it is on my *istDs and K-x, all other Pentax dSLRs.

this is how you should be able to set up your camera for using manual lenses incl. focus confirmation:

Go to Custom Menu and scroll down.

"FI with S Lens used" >> select "Available"

and if you haven't done this already..

"Using aperture ring" >> select "Permitted"

and set the focus mode switch on the side of the mount to 'M'

If the *istD behaves like my *istDs you can use M42 lenses in Av mode. Viewfinder will darken ( = dof preview Wink

) when stopping down.

For K mount lenses without electrical contacts use M mode. Lens stays open / viewfinder stays at it's brightest even if stopped down. Before releasing press "AE-L" button, this will stop down the lens to meter and select shutter speed. Turning the on/off switch to the far right position will stop down the lens for as long as you keep the switch in this position = dof preview

Some M42 lenses also may meter better in M mode and pressing AE-L button than when using Av mode, for M42 lenses both these modes can be used alternatively

peterqd · Expire: 2014-01-04

GrahamNR17 · Expire: 2012-09-06

I only have the setting "F stop other than A" which is the way to make the *ist D to work with manual lenses. I am familiar with later versions like yours from my K100D that I had a couple of years ago, but this one doesn't have those extra settings, which is a shame.

Anyway, I can't get any focus confirm to work at all with the M42 lens Sad

but if I fit the 18-55mm Samsung, then it does work as you describe in MF mode. I guess the original *ist ain't all that clever compared to later versions.

I've now removed and re-seated the focus screen. Thanks for the excellent links to the instructions - really useful Cool

I shall save those instructions for future use too.

Tomorrow morning I shall conduct some focussing tests with the M42 lens as per today, and also the 18-55 in MF mode. Maybe the problem is my eyes Shocked

kuuan · Expire: 2014-12-26

for the M42 lenses that do not give focus confirm on *istD.. shortening some contacts on the camera mount with a foil may make it work. I don't know which contacts, googling it you may find out - or you could scrap off the black paint on the mount of the lens to do the job

if that doesn't work "Superimpose AF Area" set to "ON" will at least have the red AF indicators light up when in focus, I think..

GrahamNR17 · Expire: 2012-09-06

I have done some more tests. I am only noticing the focus shift on the Helios f2 lens. I did a dozen shots, re-focussing each time, and the focus was generally slightly further away, but sometimes very close. On the Industar f3.5 and Lydith f3.5, the focus was ok. Using the Samsung AF zoom in MF with focus confirm, it was ok too.

My conclusion is that the focus screen is probably ok, but the very slight movement of the focus ring on the f2 lens when hunting for perfect focus is enough to move the focus point quite a long way, and my old eyes aren't good enough to focus with a plain screen. The f3.5 lenses have that tiny bit more depth of field, so it is probably making-up for my poor eyes.

The photos with the confirm peep and LED signal with the Samsing lens were all perfect focus. But I guess that works by different method than the focus screen. That said, at 50mm setting the zoom is f5.6 wide open, so again makes up for my poor eyes.

I shall over the coming year add some PK/A lenses in these focal lengths so I can use the focus confirm function of the camera, and in the meantime not use the Helios wide open until I can get the split-prism screen.

Perhaps I need to convince Attila to create AFLenses.com Laughing

I hate all the stuff that stops working properly as I get older Crying or Very sad

Jieffe · Joined: 04 Nov 2007 Posts: 754 Location: Belgium

GrahamNR17 · Expire: 2012-09-06

kuuan · Expire: 2014-12-26

very good recommendation of Jieffe!
a good focus screen and optional a viewfinder magnifier, that's what counts Wink

( I personally forgot altogether that my camera has focus confirm and trust my eyes using a good split focus screen and the magnifier )

If you miss the focus confirm with the M42 lenses, if it is true, as I believe, that it is the blank metal of the K mounts which enables the focus confirm, than there is an obvious solution to also get it when using black painted M42 mounts.

It sounds as if your Helios may have a problem. Fussing with the focus screen when using it won't help resp. I'd advice to obviously use a perfectly well working lens to calibrate your focus screen, if so needed at all.

ludoo · Expire: 2011-12-05

Graham, if you want I still have the focusing screen I used in my old *istD: it wass custom cut with a machine from a Canon EE-S and it works great for mf lenses.

Unfortunately, the guy who cut it (a fellow Italian Pentax user) wrapped it in lens paper then wrote on the paper with a felt pen, staining the screen. Smile

I cleaned it, but there are a couple smallish very faint stains left. They did never bother me and are invisible unless you frame a white wall. The screen of course works much better than the stock one for mf.

If you want it send me your address, and I will ship it sometime next week.

Ludo

GrahamNR17 · Expire: 2012-09-06

Really?

I don't know what to say Embarassed

That's very kind of you Embarassed

I promise one day I shall re-pay you kindness Very Happy

ludoo · Expire: 2011-12-05

GrahamNR17 · Expire: 2012-09-06

I want to publicly thank you, Ludo Very Happy

The focus screen arrived today Cool

Thankyou so much. This evening I will fit it following your detailed instructions

ludoo · Expire: 2011-12-05

Attila · Expire: 2025-11-18

48 hrs is good between two cities Shocked

GrahamNR17 · Expire: 2012-09-06

It was the stamps, four of them, all with photo of the Pope on them. The package had help from above Laughing

Orio · Expire: 2012-12-04

poilu · Expire: 2019-08-29