[chrism24]

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Hi there

Just wondering if anyone has installed an AS-80 focus screen in a 645z camera. It's the equivalent screen from the 645N series but looks to me like it might be identical?

Reason I ask is that the used Pentax 645z I bought has scratches all over the focus screen and I'm keen to replace it.

The genuine DF-80 screen for the 645z is very hard to find

Any thoughts would be much appreciated

Chris

[barondla]

Hi there

Just wondering if anyone has installed an AS-80 focus screen in a 645z camera. It's the equivalent screen from the 645N series but looks to me like it might be identical?

Reason I ask is that the used Pentax 645z I bought has scratches all over the focus screen and I'm keen to replace it.

The genuine DF-80 screen for the 645z is very hard to find

Any thoughts would be much appreciated

Chris

First, welcome to the Pentax digital medium format family and forums. The 645N focusing screen fits all the 645 models except the original film camera. I was wanting to try the ab/82 screen made for the N. Unfortunately, the one I found sold for over $300. I'd rather buy lenses.

Would love to see some of your 645 images.
Thanks,
barondla

[robiles]

Hi there

Just wondering if anyone has installed an AS-80 focus screen in a 645z camera. It's the equivalent screen from the 645N series but looks to me like it might be identical?

Reason I ask is that the used Pentax 645z I bought has scratches all over the focus screen and I'm keen to replace it.

The genuine DF-80 screen for the 645z is very hard to find

Any thoughts would be much appreciated

Chris

I do no know where you are located but the Ricoh Dach (Germany, Austria and Switzerland) online shop has all 3 focusing screens available (DG, DK and DF-80) to buy - new - even if a bit expensive (99€).

[rdenney]

I’m using an AA-82 microprism screen in my 645z with only positive results.

Rick “no hesitation” Denney

[johnha]

I’m using an AA-82 microprism screen in my 645z with only positive results.

Rick “no hesitation” Denney

How tricky was it to fit Rick, I have one for my D but haven't got round to fitting it?

[kaseki]

The primary difference (and possibly the only difference other than the particular grid patterns) between 645N and the 645Z, 645D screens is that the latter have grids that stop at the edge of the photo sensor field of view, whereas the N screens extend to the edge of the screen to cover the film field of view.

Please see the Accessory Reviews page and compare 645 screens under Focusing Screens (Genuine Pentax) with 645 screens for Focusing Screens (Genuine Pentax -- Legacy).

[rdenney]

How tricky was it to fit Rick, I have one for my D but haven't got round to fitting it?

Not tricky at all. The screen should come in a case that uses a tool to grab the screen by a tab so that you don't ever have to touch it.

Rick "took five minutes, most of which was studying the design" Denney

[rdenney]

The primary difference (and possibly the only difference other than the particular grid patterns) between 645N and the 645Z, 645D screens is that the latter have grids that stop at the edge of the photo sensor field of view, whereas the N screens extend to the edge of the screen to cover the film field of view.

Please see the Accessory Reviews page and compare 645 screens under Focusing Screens (Genuine Pentax) with 645 screens for Focusing Screens (Genuine Pentax -- Legacy).

I hadn't thought about the different format sizes--it's a good point about the grids. The standard screen is ungridded, and the one I installed also has no grid (but it does have a microprism focusing aid).

But I tend not to use grids in any case (especially when they aren't provided )

Rick "getting more from the microprisms" Denney

[chrism24]

First, welcome to the Pentax digital medium format family and forums. The 645N focusing screen fits all the 645 models except the original film camera. I was wanting to try the ab/82 screen made for the N. Unfortunately, the one I found sold for over $300. I'd rather buy lenses.

Would love to see some of your 645 images.
Thanks,
barondla

Thanks barondla, clears that up. 👍

And thanks to everyones replies. I'm going to put the camera into Ricoh Australia for a service and see if they can replace it.

Chris

[TDvN57]

Thanks barondla, clears that up. 👍

And thanks to everyones replies. I'm going to put the camera into Ricoh Australia for a service and see if they can replace it.

Chris

A while ago I replaced the focussing screen with some makeshift solutions, and recently I found a focussing screen with a small split image in the center UB-21. They dont make these anymore and the one I got was made for the old 645 cameras, prior to the "n" series. The nib that allows the screen to go in only in one way, was in the wrong location. I carefully "shaved" it off the screen with a box cutter, and then it fitted perfectly in the 645z. My previous solution was with split image and the donut ring around it, which I found distracting. The really tiny split image is ideal and gives me more flexibility in manual focus. I know this is highly subjective, but it works for me.

Here is the link to the site where I bought it for USD35.

Pantax 645 Focusing Screen UB-21 Split-Image 38533/NOT for 645n 17014014800 | eBay

Tip: Dont use the tool that comes with the screen, it will leave bad scratch marks. I use gloves and soft cloth to handle the screen, touching the edges only.

[kaseki]

A while ago I replaced the focussing screen with some makeshift solutions, and recently I found a focussing screen with a small split image in the center UB-21. They dont make these anymore and the one I got was made for the old 645 cameras, prior to the "n" series. The nib that allows the screen to go in only in one way, was in the wrong location. I carefully "shaved" it off the screen with a box cutter, and then it fitted perfectly in the 645z. My previous solution was with split image and the donut ring around it, which I found distracting. The really tiny split image is ideal and gives me more flexibility in manual focus. I know this is highly subjective, but it works for me.

Here is the link to the site where I bought it for USD35.

Pantax 645 Focusing Screen UB-21 Split-Image 38533/NOT for 645n 17014014800 | eBay

Tip: Dont use the tool that comes with the screen, it will leave bad scratch marks. I use gloves and soft cloth to handle the screen, touching the edges only.

TDvN57. Would you mind expanding on this note a tad and inserting it as a review in the UB-21 section: Pentax 645 UB-21 Split Image Matte focusing screen reviews - Pentax Camera Accessory Review Database
Thanks.

[chrism24]

Thanks everyone for all the comments

Since posting I had planned on buying the Pentax AS-80 focus screen which is the standard screen in the Pentax 645nii, from a Japanese Ebay seller. I messaged the seller asking about the compatibility issue with the 645z and they actually did some digging and came back to me with an answer through the Ricoh website stating that the "light distribution is different and that correct and accurate metering can't be achieved" I thought this was pretty amazing of the seller to go to so much trouble and also interesting as it goes against a few peoples posts from this forum. Actually correct that, a few replies said it "fits" with no trouble but I don't think anyone spoke about metering accuracy.

I've held off buying the screen for the minute and wanted to reach out on the forum again, asking for peoples experience with using 645n and nii screens in 645z and D digital bodies.

Thanks

Chris

[kaseki]

It is certainly possible for the bi-directional reflectivity (scatter distribution) to be different for one matte surface vs. another. I would be impressed if the difference were more than a stop, though. Because the Z reportedly can be operated slightly underexposed with low-light-level regions pulled up in post, one direction of possible exposure mis-measurement could be accommodated that way. Or, exposure compensation bias could be used once the effect was measured. (P-TTL works with the mirror up, so no compensation would be used for flash exposures.)

I think this could be most easily determined by using a stable continuous light on a test subject (or test chart) and comparing for each screen the camera's proposed iso/aperture/shutter time in one of the programmed modes. Of course, one has to have both screens and the time to experiment.

[rdenney]

It doesn’t seem to me that my 645z meters any differently with the old microprism screen vs. the stock screen. It might handle a bright spot right at the focusing aid a little differently, I suppose, but I don’t usually have subjects like that.

Rick “not thinking a flat test surface like a gray card would bring out any differences” Denney

[barondla]

It doesn’t seem to me that my 645z meters any differently with the old microprism screen vs. the stock screen. It might handle a bright spot right at the focusing aid a little differently, I suppose, but I don’t usually have subjects like that.

Rick “not thinking a flat test surface like a gray card would bring out any differences” Denney

Heard that the K-1 doesn't meter correctly with microprism or split image focusing aids when using the spot meter. Probably the same with 645 digital cameras.

Thanks,
barondla