Sigma 600 mirror

BeardsAreBest · Joined: 09 May 2014 Posts: 286 Location: Australia

Nice photo cooltouch!
the focusing is a bugger but when you get it it's very pleasing.
I have a few images with the same ghosting and found underexposing a little seems to eliminate this.
As i mentioned the use of focus peeking is a great help too if its a feature on your camera.
I had a bunch of not focused images but it just makes me want to try harder as there is potential for sharp photos with the sigma.
I've not used any other mirror so cannot compare but am very pleased with the results from this lens.
I only cleaned and reassembled mine as i don't have the know or the how for any type of adjustments and didn't want to go back together out of alignment.

cooltouch · Joined: 15 Jan 2009 Posts: 9097 Location: Houston, Texas

My experiences with most lenses I've had to dismantle and reassemble is that they only go back together one way. And when reassembled, they are fine, optically. In other words, no recollimation is required. That was true for the Tamron 55B I dismantled as well. The glass fits into its pocket or socket or groove or what have you and once it's in place, it's good.

I don't have any reason for dismantling my Sigma -- it's perfectly clean inside with no fungus -- and I'm afraid that if I did, it wouldn't matter anyway.

I'd rather just learn to use it, hopefully increasing my percentage of keeper shots.

My NEX 7 has focus peaking, but I have learned that it isn't precise enough for nailing exact focus with a lens like this Sigma or the Tamron 500/8. There is still a fair amount of movement I can make with the focusing collar and I'll still see the peaking showing on the specific area I'm focusing on, and I know from experience that to nail precise focus, there isn't nearly this much play allowed. So I'll get close using peaking, then I use either the 5.9x or 11x image enlargements to get as close as I can.

I'll try underexposure again, but that photo of the lily I showed before, with the ghosting around it? I had reduced the EV on that shot by -1.0. It didn't seem to make a difference with that subject.

BeardsAreBest · Joined: 09 May 2014 Posts: 286 Location: Australia

Apologies i should have mentioned the camera (A7) has a digital zooming that i use to focus which i like to call peeking as you kind of zoom in and have a peek at what you are focusing on.
The actual peeking thing that colors the focal plane i've found to be only good with fast lenses and have it turned it off most of the time.
Definately keep trying tho.
Smile

Beard.

WNG555 · Joined: 18 Dec 2014 Posts: 784 Location: Arrid-Zone-A, USA

[cooltouch]

Hmmm, that does look a lot better.

Had me wondering if temperature might be a factor...given my first try was immediately after UPS handed it to me. It was quite warm to the touch from sitting in the truck, in the desert.

Took two shots on a tripod, no joy. Same results even at room temp. So, mine certainly has something bumped out of alignment.

cooltouch · Joined: 15 Jan 2009 Posts: 9097 Location: Houston, Texas

With the Sigma and many other long telephotos, temperature differences have been taken into account. This is evident in the focusing range, where you see you can focus well past infinity. Expansion of the lens due to heat can be adjusted out because of this extra room in the focusing range.

I've decided that I'm gonna give my Sigma a try with a film camera. I've loaded up an expired but frozen roll of Fuji 100 print film into my EOS Elan IIe and all I need now are some likely subjects. It was overcast and rainy all day today so I wasn't able to get any work done with it. I guess I could shoot some indoor stuff, far as that goes. The lens does focus close. My wife has cut some fresh flowers and placed them in a vase. Maybe I'll go take some shots of those. It's a start, at any rate.

Only problem with using this EOS is I don't have any focusing aids. And the camera's little dot in the viewfinder meaning "in focus" doesn't light up with this lens either. Back in the day when I was using my C/FD Sigma, I had a Canon eyepiece magnifier that I would often use with this lens. It helped quite a bit until I finally got pretty good at nailing focus. I'll have to check my accessories inventory -- I might still have a Canon magnifier "S" that I've forgotten about, which might just work with that EOS.

Here are some pics I took with my C/FD version, taken back during the mid-1980s. I've probably posted them at the forum before, but I don't recall when or in which subforum. Besides, this is the first time I've brought them altogether into a single posting.

Canon F-1, Sigma 600mm f/8, Fujichrome 100

Canon F-1, Sigma 600mm f/8, Fujichrome 100

100% crop of above:

Canon FTb, Sigma 600mm f/8, Kodachrome 64

100% crop of the tall ship, Windjammer

Canon A-1, Sigma 600mm f/8, Kodachrome 64

100% crop of above:

tb_a · Expire: 2019-08-28

cooltouch · Joined: 15 Jan 2009 Posts: 9097 Location: Houston, Texas

tb_a · Expire: 2019-08-28

kryss · Expire: 2017-09-18

Would a Canon Speedfinder help?

cooltouch · Joined: 15 Jan 2009 Posts: 9097 Location: Houston, Texas

Yes, Thomas, it could very well be we're talking about the same thing. The whole concept of contrast, resolution, and sharpness is misunderstood by many, which is why I tried to present a precise definition. Mine is independent of resolution as well, because it is the maximum sharpness available at a given resolution, in other words, resolution is a given part of the equation, if you will.

Here is a great article by Erich Heynacher and Fritz Kober of Zeiss, that goes into some detail explaining the differences between contrast, resolution, and sharpness, and how they interact with each other, and the results they have in terms of perception. I've always felt the article to be very informative and indeed helpful in understanding this topic, and relieving confusion.

http://www.forums.camera-info.com/contaxinfo/pdf_files/Zeiss-Resolving_power_and_contrast.pdf

WNG555 · Joined: 18 Dec 2014 Posts: 784 Location: Arrid-Zone-A, USA

Michael,

I want to pass along my findings from venturing inside the Sigma 600 last night.

As it turns out, it was not necessary to attempt to unscrew everything (like in the above link) to gain access to discover my fault. Although, further disassembly may be required for a permanent fix.

As BeardsAreBest mentioned, the focus barrel and stop is held together by TAPE. Just pull off the rubber grip, remove the tape and the front outer half unscrews from the helicoid. Just don't do what I did. I forgot to mark the two pieces with a sharpie marker for reassembly. So, I now must realign for infinity.

Once the front was removed, I found haze on the smaller front mirror. Unfortunately cleaning had no effect as it was on the back side of the glass. This probably hurts the contrast some. Since it's glued on, no further could be done.

Inspecting the rear half... the central column and rear mirror seems attached together, and screwed onto the back end somehow. I found that it was loose and I could move it laterally. I had found the cause of my ghosting. Turning it clockwise didn't tighten it nor center it. After several tries and tests on a tripod, I pulled on the column forward which seemed to have centered the whole assembly and the mirror.
It removed the play too, but how permanent without further overhauling, I don't know. The rear half is not obvious as to how it was assembled.

Test photo shows the ghosting is gone. But the image is still not sharp enough no matter how much effort focusing. So, it's another issue, maybe the haze. Or the column assembly is too far forward by a fraction of a millimeter. I would assume this longitudinal tolerance to not be a factor (since the focusing portion compensates for it.) But this assumes the rear element(s) are also fixed to the column.

If I can't get it to focus better to at least resemble BeardsAreBest's samples, then the lens is useless. Not sure if I should put in the effort to try to completely disassemble the rear portion or simply return it for a refund.

Should you decide to try a go at it yourself, just make sure to mark the focus rings with a marker, and not disturb the lube on the threads. I wiped a little bit off and the focusing got heavy. I don't know what magic grease lens makers use, but it's slippery and not viscous. I had to dab some grease on the first few threads to get it to turn again. But it's now heavier than before.

cooltouch · Joined: 15 Jan 2009 Posts: 9097 Location: Houston, Texas

Well, I dunno if I feel like tearing into my lens that far, but it might be worth it.

Actually, I found it sort of hard to tell about sharpness in your shots of the long leaves. The first one looks like some of the leaves were moving during exposure, in fact. The pic of the palm tree's trunk is soft but I suspect that might be to the cloudy element in your lens. Tough break that.

I know how you feel. Some time back, I bought a Tamron 55B, which has a design in which a secondary mirror is glued to the front element. This secondary mirror had begun to separate from the glass it was glued down to. No way to remove it, so no way to get to the separation so I could reglue the element. I ended up selling it "as is" on eBay. Somebody gave me $50 for it; I was surprised.

WNG555 · Joined: 18 Dec 2014 Posts: 784 Location: Arrid-Zone-A, USA

I understand you. Same here, do I continue down the rabbit hole? Smile

The 'after' shots and their crops show what a big improvement over the the first post. Both of the tree trunk. I have other test shots that show major difference. But pixel peeping and one can still find a bit of ghosting very minute though. The hairs off the palm leaves, at 100% crop, shows a hair ghost.

The first shot was blowing in the wind. But shutter speed was high.

You may have decided it for me, I can't do much more about the haze. Ultimately it will prevent me from getting this lens acceptable.
Return this defective one and wait for another down the line.

BeardsAreBest · Joined: 09 May 2014 Posts: 286 Location: Australia

I think this lens was made for bird photography.
I love it.
Resize only.

100% crop

WNG555 · Joined: 18 Dec 2014 Posts: 784 Location: Arrid-Zone-A, USA

Excellent! Envious. Wink

cooltouch · Joined: 15 Jan 2009 Posts: 9097 Location: Houston, Texas

Very nice. I've been looking for birds too, but no luck so far. I suspect that my Sigma isn't as sharp as yours, though.

cooltouch · Joined: 15 Jan 2009 Posts: 9097 Location: Houston, Texas

I've been giving this Sigma 600 a lot of thought lately. And part of this process has been going through all the listings I could find on eBay. I'll probably also do a Google image search too, which will help some.

You know, I know of no other lens that has been available in so many different color schemes. It appears that the earliest Sigma 600 was available in black only and it was a gloss or semi-gloss finish. But by the mid-80s or so, the different variants began to appear. So far, I've seen the Sigma 600 in the early gloss black, a later textured black, a shiny silver metallic enamel, textured white, textured gray, and a drab green color (good for camouflage, perhaps?). That's at least six different colors! I don't know exactly how long this lens was made, but I suspect it was something less than 10 years -- perhaps 8 or so. Does that seem about right to you?

I've also noticed that they redid the text on the lens. On the very early ones the script engraved on the outside of the front filter ring was very large, perhaps almost 1cm in height. With the redesign, the text shrank to maybe 3mm or 4mm. I've also noticed that on some of the earlier designs the filter holder is metal with a longish handle protruding, whereas the later ones use a plastic holder with a much smaller handle. Plus, with the Canon FD mount, they used an early breech-lock design and later a breechlock design that waas a close imitation of the New FD mount. The one I bought had the later "New FD looking" mount. But there's one on eBay right now that has the breechlock and the long metal handle for the filter holder. You will also see two basic designs to the textured ribbing on the rubber focusing collar. Either a bunch of rectangles or parallelograms, where they're slanted across the collar's surface. At first I thought this slant style was indicative of early lenses, because the one I bought in 1984 had the slanted ribbing. Yet the earliest ones I found on eBay didn't have this. And some of the later ones, with s/n's above 1 million had the slant. So I don't know what was going on there.

I've also been keeping my eye on serial numbers. The early gloss black lenses I've found have serial numbers in the 2xxxxx and 3xxxxx range. But all the later finishes that I've been able to see serial numbers on have been over 1xxxxxx, except for one, and it was 9xxxxx. Typically the ones over 1xxxxxx are 101xxxx, 102xxxx, and I saw one that was 103xxxx. My own Sigma, which has an EOS mount, which means it was built in 1987 or later (probably later), is 102xxxx. Now it seems highly improbable to me that Sigma built over 1 million of these mirrors, but if the serial numbers are sequential with no skips, that's what this means. No, I was originally more inclined to believe that they bumped the s/n to over 1 million when they came out with the new, more modern, textured look. But then I found a lens with a 9xxxxx s/n, so that sort of blew that notion out of the water. But so far, I haven't found any Sigma 600 mirrors with a s/n in the 4 to 8 hundred thousand range. I wonder about this. I must have examined twenty lenses last night and not one was found in that range. They were bunched up in the 2xxxxx-3xxxxx range or 101xxxx to103xxxxx range, with the one 9xxxxx outlier.

I've been examining the serial numbers so I could get a feel for the ages of the lenses because I have a theory that has to do with the manufacturing process. My brother in law is the chief engineer at igloo Corporation -- you know, the people who build coolers and ice chests? And one of his jobs is overseeing the production and use of molds for their products. These molds are very expensive to make, but they also have to last a long time and they're subject to rather harsh environments, being injected wth molten plastic and all. But he will tell you that these molds wear out after a while and they have to be replaced. And its toward the end of a mold's life where its dimensions may begin to wander a bit. This same sort of problem is faced by the automotive industry and any other industry involved in producing heavy products. Just because a new car rolling off the assembly line is new, it doesn't mean it's good. If that car was made on machinery that is worn out, where tolerances are no longer being held to their required minimums, then even though it's new, it could be a piece of junk. I know for a fact that this happened in the US auto industry when Chrysler absorbed AMC-Jeep. AMC was building its cars on worn-out machinery that was overdue for replacement, but AMC wasn't generating enough capital where they could afford to do so. So when Chrysler bought out AMC-Jeep, they were hoping for all the increased production capacity but instead what they bought was a bunch of production space with worn out machines. And the Chrysler products that were being made shortly after the merger reflected this, especially the engines that were being machined on machines that weren't holding factory spec tolerances anymore.

So this got me to thinking about this Sigma 600. I'm asking myself, what if the later Sigma 600s -- like mine -- were being produced on machinery that was getting worn out and the tolerances just weren't there anymore? My first Sigma in Canon FD mount, I bought in early 1984, so it was probably built in 1983 or earlier. My current Sigma was probably built in 1988 or later. That first Sigma I owned was a very sharp lens, whereas this current one is just so-so. And I can't help but wonder if maybe the reason for the difference is the age of the manufacturing machinery.

What do you think? Does this make sense to you? One quick way to see if my theory has any truth to it is to find out what BeardsareBest's Sigma 600's serial number is. So, how about it, BaB? Care to tell us what the s/n of your lens is?

[Edit] Well, hell! I just constructed what seemed to me to be a reasonable argument and I scroll up only to see WNG555's Sigma 600 and I immediately notice that it is an early version. S/N on that lens is probably in the 2 to 3 hundred thousand range. Yet he's having problems with his, as we've seen. So either his is an exception to my carefully crafter argument, or my carefully crafted argument is worthless. Oh well. I need more data!

Kei · Joined: 08 Jan 2015 Posts: 142 Location: S. Wales UK

When focused properly it does seem to be a pretty decent lens. I've got an OM fit version that I used with my canon. Now I've moved to nikon I can't fit it. This is one of the best images I got with it, a bit noisy.

cooltouch · Joined: 15 Jan 2009 Posts: 9097 Location: Houston, Texas

Good detail, nonetheless. Were you able to get that close to the squirrel, or is that a crop? Oh, and can you give me the first couple of digits of your Sigma's serial number?

WNG555 · Joined: 18 Dec 2014 Posts: 784 Location: Arrid-Zone-A, USA

FYI, My defective one is: 900928, and yes, it's an older model, with the chromed steel handle for the filter holder, straight focus rubber pattern, and a push button release to select portrait or landscape for the tripod collar.
Too bad, mine is going back tomorrow.

Don't forget, there was also an XQ version offered. I missed out on one of those on ebay. Perhaps that's where the Ser. # hole goes.

cooltouch · Joined: 15 Jan 2009 Posts: 9097 Location: Houston, Texas

I'm not familiar with the XQ version. What was the difference? Have you ever used one?

Your 9 hundred thousand one seems as if it's more like the ones I saw that had s/n's in the 2 to 3 hundred thousand range. Huh, curious. I have a line on an early one in Canon FD mount that I'm thinking about picking up that resembles yours, but now that I read your problematic one sounds as if it's from the same generation, I don't know.

BeardsAreBest · Joined: 09 May 2014 Posts: 286 Location: Australia

Serial on mine is 219553.
straight rubber grip
plastic filter mount.
hope this helps Smile

Kei · Joined: 08 Jan 2015 Posts: 142 Location: S. Wales UK