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Sigma 600 mirror
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PostPosted: Wed Jul 01, 2015 6:52 pm    Post subject: Reply with quote
My Sigma was stopped by customs Very Happy
Seller does not included invoice, and my ebay invoice was not accepted, since it can't be an evidence, so I need to get bank report that I actually paid $51 for it Smile


PostPosted: Wed Jul 01, 2015 11:03 pm    Post subject: Reply with quote
Rolling Eyes
Customs...don't you just love them...must take their pound of flesh from everyone.


PostPosted: Sat Jul 04, 2015 4:04 pm    Post subject: Reply with quote
The battle continues, they said that OK, I've paid $51, but lens will be sent to "expertise" to determine, whenever it was really used, as seller described, or we were just altered description to avoid taxes.


PostPosted: Sat Jul 04, 2015 4:10 pm    Post subject: Reply with quote
Geez, what do those clowns think they have? A solid gold lens or something? The price for a Sigma 600 is easy enough to determine and all the $51 represents is he got it for a good deal!


PostPosted: Sat Jul 04, 2015 5:33 pm    Post subject: Reply with quote
Maybe they should learn from Austrian customs. If something is unclear you have to tell them the *bay number of the item even by phone and they look it up themselves to check the real selling price. For used items in such a low category they wouldn't care at all. It's not even taxable when below 150 Euro (if I recall it rightly). To buy goods the U.S. are far better but obviously for imports we have less problems here. Wink


PostPosted: Sat Jul 04, 2015 8:03 pm    Post subject: Reply with quote
Yes but they say that ebay listing is not telling complete story. Who knows, how much you have sent via paypal or via other payment methods? And since their suspictions are only suspictions and are not in court hearing, they can't ask bank, paypal or whatsoever, to give them complete story of your transfers...

Deadline is 15th july. If they will not make any decision up to that day, I can sue them for unnecesarily delaying my parcel and hurting my business, emotional and other sides Smile


PostPosted: Sun Jul 05, 2015 2:26 am    Post subject: Reply with quote
CuriousOne wrote:

Deadline is 15th july. If they will not make any decision up to that day, I can sue them for unnecesarily delaying my parcel and hurting my business, emotional and other sides Smile


We are living in a crazy world. That's certainly a proof for it. Wink


PostPosted: Sun Jul 05, 2015 4:40 am    Post subject: Reply with quote
Simply incredible, we are definitely living in insane times.
Rolling Eyes


PostPosted: Sun Jul 05, 2015 11:09 am    Post subject: Reply with quote
There's a small flea market near the customs office. I rarely visit it, since it mostly focuses on porcelain, awards, etc. But, just for curiosity, I went to check it, and I was rewarded - got Jupiter-3 in contax RF mount along with "Kiev" camera for a good price Smile The lens is already for sale on ebay.


PostPosted: Wed Jul 08, 2015 10:30 am    Post subject: Reply with quote
Got this lens finally!

The mount is quite easy to convert - the rear FD mount assembly is connected to main body via 3 screws, unscrew them, remove mount and you get flush mounting surface, install whatever you want. I will adapt it to M42, for better sales if needed.

Regarding the quality, did only couple of handheld shots so far, but contrast and sharpness is much better than say 500/8 mirror Vivitar lens.


PostPosted: Wed Jul 08, 2015 8:01 pm    Post subject: Reply with quote
Got it converted, here are first observations:

1. While focusing barrel rotates much more than say Rokinon's, most action goes in same narrow area as other mirror lens, so focusing is still very difficult.

2. This lens has excellent IQ, way better than cheap Vivitars, MTO's and Rubinars.

3. Focusing is VERY hard. Even when used with peaking, af confirm and so on, movement of lens focusing barrel by 0.1mm changes focused distance by nearly 1 meter, even on objects 200 meters away!

Due to absence of the moon, had to use neighbour's windows blinds as resolution test target. Below is 100% center crop, taken using Sony SLT-A77Mk2, ISO 800, 13 second exposure. I was not able to focus with such sharpness again.
Image is at default settings, no post processing. Check the vertical lines, how sharp they are, despite being shot thru double walled window!


PostPosted: Wed Jul 08, 2015 10:03 pm    Post subject: Reply with quote
Well, it isn't the best subject to evaluate that lens, but there are aspects of it that would suggest good sharpness. We will look forward to more posts from you and this lens in the future.


PostPosted: Wed Jul 08, 2015 11:52 pm    Post subject: Reply with quote
Looks like you got a very good model. Will be looking forward to your Moon shots.


PostPosted: Thu Jul 09, 2015 3:52 am    Post subject: Reply with quote
Yes, this lens seems to have one of the best sharpness in mirror lens I've ever seen (#1 was Minolta 500/8 AF).

Overcast morning, center crop, no pp:



Same morning, right edge crop, auto levels & sharpen +1:



So this is great lens, but I need longer one, so I will sell this one, and will search for 800mm or better.


PostPosted: Thu Jul 09, 2015 4:40 pm    Post subject: Reply with quote
Found a solution how to make focusing easier - I've shortened flange distance as much as possible, so "infinity" was shifted and now lies in "macro" area, making focusing easier. It does not helps very noticeable on DSLR, but still better, than without modification. However, on NEX, when used with "slim" M42 adapter, focusing is much easier.

Here's how mount looks now. This is the preliminary "design", silver colored plate will be machined again, I was not curious enough and can't imagine even that Sigma engineers might drill holes not at 120 degree angles Very Happy



P.S. This lens is for sale, so if anyone wants it and also would like to have custom text on that plate - it's time to PM me Smile (Text will be in black color, what you see now is just cutout, without paint applied)


PostPosted: Thu Jul 09, 2015 9:00 pm    Post subject: Reply with quote
Very good indeed! The car's rear is quite detailed.


PostPosted: Fri Jul 10, 2015 5:27 am    Post subject: Reply with quote
Not moon, a brick wall, but if anyone interested in RAW output with this lens, here's an example:

http://www39.zippyshare.com/v/etnpbJ75/file.html


PostPosted: Tue Jul 14, 2015 3:05 pm    Post subject: Reply with quote
Here you can see micro focus adjustment gear for this lens. The construction is just proof of concept, final will be made in different way, from different materials and also will include fluid dampener for ultra-smooth focusing.

I think I will post this gear for sale separately - it is very easy to fit it on your lens, you need to remove two screws and tighten 3 new ones. No changes made to lens and operation is fully reversible.



PostPosted: Tue Jul 14, 2015 9:27 pm    Post subject: Reply with quote
Ingenious! Reminds me of lenses made for video rigs.

This should cut down on user-induced vibration while focusing. This is a major problem using these mirror lenses....image oscillating hampering one's ability to see the subject in focus or not.


PostPosted: Wed Jul 15, 2015 3:52 am    Post subject: Reply with quote
Thanks!

This system introduces 1:2.5 reduction to focusing mechanism, making focusing easier. Currently I'm thinking about going 2 ways - introduce additional gear, to get say 1:6 reduction and also decrease teeth size for precise adjustment, or just equip it with small dc motor and pistol grip with focusing slider.


PostPosted: Thu Jul 16, 2015 4:47 am    Post subject: Reply with quote
CuriousOne, I have a suggestion, that is, if you're not using one already. Have you thought of using a stepper motor to control the focus? As you probably know, stepper motors are capable of very tiny movements for each step and are often used in devices where very high precision is necessary -- like CNC milling machines and lathes. They're also used in focusers for telescopes, in fact. Also, since this device of yours mounts to the focusing collar, how easy or difficult would it be to make one for other lenses? And what if another lens is like the Type II Tamron mirror, which doesn't have a tripod mount?

WNG555, I agree that user induced vibration is a problem with long lenses. My experiences with my long lenses, including the Sigma and my Tamron 500 is that the Sigma fortunately has a very beefy tripod mount, so if it is resting atop a stout tripod, user-induced vibration is minimized. Using my Tamron 500, which does not have a tripod mount, on the same tripod is an entirely different experience. It suffers from the slightest touch and is a real challenge to focus accurately. For the life of me, I will never understand why Tamron decided to remove the tripod mount on its Type II mirror. The Type I mirror has one, although it isn't nearly as massive as the Sigma's.

My other long telephotos all have tripod mounts and, like the Sigma, are not nearly the challenge to focus that the Tamron mirror is.


PostPosted: Thu Jul 16, 2015 8:30 am    Post subject: Reply with quote
cooltouch wrote:

WNG555, I agree that user induced vibration is a problem with long lenses. My experiences with my long lenses, including the Sigma and my Tamron 500 is that the Sigma fortunately has a very beefy tripod mount, so if it is resting atop a stout tripod, user-induced vibration is minimized. Using my Tamron 500, which does not have a tripod mount, on the same tripod is an entirely different experience. It suffers from the slightest touch and is a real challenge to focus accurately. For the life of me, I will never understand why Tamron decided to remove the tripod mount on its Type II mirror. The Type I mirror has one, although it isn't nearly as massive as the Sigma's.


Well, missing tripod mounts can be easily substituted by a device like shown here from Manfrotto which is btw. better than any tripod mount on the lens itself because it's better balanced as the weight is better distributed:
http://forum.mflenses.com/minolta-rf-rokkor-500mm-f8-and-tcon-on-mft-t71740,highlight,+minolta++rf++500.html

The other story is the tripod itself. Here it turned out that normal photo tripods which are usually equipped with ball heads are not really the optimum design for such rather difficult situations (very narrow field of view and rather heavy camera/lens assemblies). Although I have a rather solid and expensive tripod it's nearly impossible to avoid pendulum like movements after touching the assembly for focusing. It took some seconds to wait until every movement was gone. This problem can be solved by using the 10 seconds self-timer. But that method is rather annoying and cannot be applied for all circumstances.

So at least from my experience it turned out that the better solution is to use a tripod which was designed for rather heavy video cameras without ball head. This avoids those pendulum effects.

However, if you managed all this, the rather tricky focusing part is still do be done correctly. Wink


PostPosted: Thu Jul 16, 2015 8:50 am    Post subject: Reply with quote
Thank for the interest.

In fact, I already have stepper version going on, and large scale model already built for testing purposes, you can see it on the picture Smile But steppers have one disappointing limitation - when going small size, their force decreases rapidly, and price goes up rapidly for tiny and capable steppers ($60 for high torque small stepper). Tiny DC motors still have great torque (cost under $Cool. So as my practical experience shows, DC motor with proper feedback (encoder, hall sensor, whatever), will provide better torque and comparable precision for camera focusing needs.


I can manufacture these "drivers" for any lens and any mounting system, for lens without any mechanical mount, it will be done like 2 piece clamp, one will attach at part that does not moves. I'm also building that system for testing, will provide photos shortly.


PostPosted: Thu Jul 16, 2015 11:25 am    Post subject: Reply with quote
I have to agree about tripods - an old VHS camera like Panasonic M3000 era tripod is way better for tele lens and can be head for much cheaper, than modern, ball head tripods.


PostPosted: Thu Jul 16, 2015 6:42 pm    Post subject: Reply with quote
tb_a wrote:

Well, missing tripod mounts can be easily substituted by a device like shown here from Manfrotto which is btw. better than any tripod mount on the lens itself because it's better balanced as the weight is better distributed:
http://forum.mflenses.com/minolta-rf-rokkor-500mm-f8-and-tcon-on-mft-t71740,highlight,+minolta++rf++500.html

The other story is the tripod itself. Here it turned out that normal photo tripods which are usually equipped with ball heads are not really the optimum design for such rather difficult situations (very narrow field of view and rather heavy camera/lens assemblies). Although I have a rather solid and expensive tripod it's nearly impossible to avoid pendulum like movements after touching the assembly for focusing. It took some seconds to wait until every movement was gone. This problem can be solved by using the 10 seconds self-timer. But that method is rather annoying and cannot be applied for all circumstances.

So at least from my experience it turned out that the better solution is to use a tripod which was designed for rather heavy video cameras without ball head. This avoids those pendulum effects.

However, if you managed all this, the rather tricky focusing part is still do be done correctly. Wink


Thanks for that link, I hadn't seen it before. Can you tell me that Manfrotto device's part number or name? I'll wager that, since it's Manfrotto, it'll probably cost about $200 or so Sad But maybe I can build a substitute. Doesn't look like it would be that hard. I've been thinking about building a tripod mount for my Tamron only, but building a universal model might be the better way to go, since I have a few other lenses that can benefit from it.

The tripod I normally use is an old Bogen. 3011, I think it is. And for the head, I have this very large no-name ball head. Somebody here identified the head for me, but I've forgotten the maker now. Anyway, it's big and it's very sturdy. Any vibration is coming from the fully extended legs and not the head.

I always use a 10-second self-timer when I'm shooting high magnification subjects like the moon. 10 seconds is plenty of time to still vibrations with my setup. They're typically gone after only 2 or 3 seconds. The only exception is if there is a breeze blowing. But if I need something for really heavy duty work, I grab my reserve beastie, my Majestic. It looks like this one here:

Click here to see on Ebay

It will handle an 8x10 easily, but it's a big, heavy brute, so I don't usually mess with it.
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