One of the reasons I wanted to move to a full frame camera was to be able to use older manual focus lenses with the same field of view as they have on a film camera. For years I’ve had a Nikkormat FTN that I got when I bought a macro lens. For the price of the package, the camera was essentially free. The meter in the camera is off by about three stops, even with a battery adapter to work around the need for old mercury cells. But other than that it works perfectly. I really do enjoy using the all manual and mechanical camera. So over the years I have picked up a few manual focus lenses for the FTN. My intention was to be able to use them on the D800E when I bought that last year.

However reality and my plans didn’t align. Sure the lenses work on the camera, but I’ve found I can’t accurately focus them through the view finder with great consistency. The bright screens that Nikon uses on their autofocus cameras do not let you see critical focus. They also do not contain any manual focus aids like a split prism, or micro prisms. The conventional wisdom says you just use the focus confirmation dot, but I found that the focus dot is lit for quite a range of distances, so hitting focus just right is difficult. I actually get better results using the focus screen than the dot, as long as the subject is well lit and contrasty. One way I can get great results is to use LiveView. But that requires a tripod, and isn’t how I want to shoot much of the time.

When I first got the camera I looked for an alternate focus screen, but Nikon doesn’t offer them for the D800 cameras. And none were available from aftermarket suppliers at the time. So for the most part my manual focus lenses stayed with my old film camera, and really were not used that much.

A month ago it dawned on me that there might now be a focus screen available so I checked Google. There are some inexpensive ones on ebay. A bit of research showed very mixed results for these screens. There is also a company called FocusingScreen.com which has a range of screens for the D800E. They seem to have much better reviews. They are generally positive, so I decided it was worth the price premium to go with them. They also seem to offer higher quality screens based on original Nikon F6 screens. I’m not sure what modifications are made, but I assume it’s cutting some of the edge material to fit.

My favorite type of focusing screen is the K type, which contains a split prism surrounded by a ring of microprisms. But there doesn’t seem to be one with that configuration available for the D800. My FTN has a J type screen which is just micro prisms, and I have no issues focusing that. So I placed an order for the F6-J based screen. Ordering was bit odd, in that the PayPal checkout showed a tax. I checked with the company and it’s not really a tax, but rather the PayPal fees. So the price advertised on the site isn’t really the price you pay. Buyer beware. Other than that slight annoyance the order went smoothly.

The screen arrived about ten days after I ordered it, which apparently included a few days for them to make the screen.

Installation is documented on the FocusingScreen site. Their English is bit broken, and the instructions seem overly complicated at first. But the actual procedure is simple, and once you’ve done it you wonder why it took so many words to describe. I don’t want to responsible, so I’m not going to try to write up better instructions (and I’m not sure I can do a better job).

So does it work? It seems to, but it also seems to have messed up the metering. That’s not a surprise since the D800 meters through the focus screen (I’m sure that’s the main reason Nikon doesn’t want to support user replaceable screens). In subsequent posts I’ll try cover some of my tests with different lenses and seeing if I can get the metering adjusted to work consistently. I’m sure I’ll run into some issues. I just hope they aren’t show stoppers.

I talked with a nice Sigma rep and he gave me the option of sending the lens and camera in to them and they would adjust the lens to match the camera. I thought about this for a bit and decided against it. The main reason was the cost. I could send the lens back to B&H for no charge, or I could pay to ship the lens and camera to Sigma. With insurance this was going to run around $65, and I would not have the use of the camera for a week or so. So I sent the lens back to B&H. If I was near the Sigma service center bringing it in would have been the easy choice.

Rather than wait for another possibly defective lens to arrive at B&H and then get to me, I called Hunt’s Photo in Manchester NH. They had a lens shipped up from the Boston store. Today I went and briefly tested it out. AF seemed accurate at all distances. So I bought the lens.

I went for a walk around the village with it once I got home to test it out. I have only briefly looked at the pictures, but in going through them I feel the AF performance is acceptable even at f/1.4 and all the distances I tried. This weekend I’ll take a little more time to see if AF fine tuning will help, but at first glance it’s working fine without it.

When I started the walk I remembered the opening conversation I had with the Sigma rep. He initially thought I was calling to report an issue with the side AF points not working. I explained the issue with distances and he dropped the subject of the side AF points. This was also mentioned by another person in this thread I started on photo.net. In theory Sigma will have a fix for this soon.

So I also tested out the side AF points on a few shots. I think my results on this are inconclusive. Some of the shots seem off a bit using the side AF points, and a few seem OK. I will need to do a more controlled study. But for the time being I can live with just using the central point and recomposing. It’s still better than my results with manual focus and a fast lens on this camera.

When I saw the early reviews for the Sigma 35mm f/1.4 DG lens I though it had a lot to offer me. 35mm is probably my favorite focal length for general photography. Reviews praise the lens for how sharp it is wide open. It also seems to have decent bokeh (out of focus rendering). I have been using a Rokinon 35mm f/1.4 lens on the D800E since I bought the camera last spring. I am really happy with the image quality of the Rokinon, but I have lots of trouble achieving perfect focus with it since it’s a manual focus lens and the D800E has a screen that’s not very good for manual focus. This really limits my use to the tripod and Live View focusing. So I ordered the Sigma, even though it was on back order.

Last Thursday it arrived. I quickly did some indoor focus tests and like all the other lens on this particular camera it seems I needed no Fine Tune focus adjustment. Cool. But my tests were done inside at close distances. We got some snow that evening and then is stopped midmorning Friday. I went out for a walk at lunch, despite the ugly gray sky. I brought a tripod to do a few tests to see if the lens was obviously decentered, and also just shot a lot of hand held shots around the village, since this is how I hope to use the lens much of the time. On Sunday I went to my brother’s house and shot a few pictures of his dog (and the rest of the family, but I won’t put them in this post), again hand held.

Upon review of the images I found some were perfectly in focus, and some were way off. I noticed the close up ones were good, and the more distant ones were soft. So I shot a lot of tests in the backyard and found that with the lens adjustment at 0 the auto focus was right on for close distances, but infinity was way off.  I adjusted for infinity which requires a -11 for the Auto Focus Fine Tune. Close up shots are now noticeably soft. I’m not sure what to make of this. Sigma will be making a USB dock and software to adjust the focus points, so maybe this is the solution. But it’s not available now, and I don’t know when it’s coming out. It also seems crazy that we need to spend more money to make our lens work as it should. I haven’t decided if I should send it back to B&H and wait for another copy to come in, or send it to Sigma for repair.

Here’re a few examples:


Full image. Focus on hanging sign.


Focus point


Background that’s more in focus than focus point.


Full sized shot of mailbox. Take fairly close up. Focus point on red flag on front.


Focus point on red flag. I’d say it got pretty close.


Close up shot with focus point on left eye. f/4


Left eye. Again the close up focus is good.

There are a few more shots over on my SmugMug gallery. Most are at f/1.4 to show the focus errors more clearly. There are a few shot stopped down. It’s pretty amazing how well corrected this lens is at wide apertures. Over all I am pretty happy with the image quality. It’ll certainly take many more shots to learn the lens. But sadly it doesn’t look like I can trust the Auto Focus, so is it really any better than my manual focus Rokinon?