| Author |
 Replies: 14 / Views: 3,577 |
|
|
Pillar of the Community
2087 Posts |
I am still awaiting the return of my schneider enlarger lens for the repair shop. In the mean time the second of my planned projects for this year came to Fruition. I had understood tilt shift could enable good coin shots. The best out of the box tilt shift lens is the Nikon PC-E Micro Nikkor 85mm f/2.8D but at US$1700.00 it was just too much for me. Especially so as I wanted a tilt shift wide angle lens for outdoors photography the best of which is probably the Canon TS-E 24mm F3.5 L II @ around US$2000.00. I did a bit of research and came up with a compromise for less than US$1000.00 I could get a Tilt shift system that included a macro lens and a wide angle. Even better the reviews I read suggested the option at the very least would outperform the canon 24mm Tilt shift. The system for Macro: Mirex tilt shift adapter (US$500) plus Mamiya-Sekor macro C 80mm F4. I use a Sony A7r. In discussions with the German manufacturer of the adapter I was advised to purchase their Mamiya 645- Canon EOS adapter. As soon as it arrived I could see why they made the recommendation. with an EOS-NEX adapter fitting the mirex to my A7r the tilt shift function is completely unimpeded. Even on Canon DSLRs one can find some of the adapters possible movements restricted. First up I did some tests and I religiously followed the mirex instructions. I set the exposure etc with the adapter centered and the lens wide open. They recommend( as every one, so I read, should always do with manual lenses focus wide open and then stop the lens down for the shot. I did this for this test panel to work out the best aperture for macro( Please note all the pictures are test shots they aren't meant to be perfect!!):  From top left reading left to right top to bottom: F4, F5.6, F 8, F 11, F16, and bottom right F22. Its hard to see with the 100 % crops but F8 to my old eyes looked the best( A 200% check seemed to confirm it.) But these first test shots confirmed my worst fears. My Mamiya 80mm was an older version: I should have got the "N" version as it was clear there was significant Chromatic Aberration( purple fringing) showing on the edge of the coin( only faintly visible in the above picture. However I was to find out that was not a major issue.... This is the subject coin ( this is the F8 test shot) the lens is in the normal position:  I had planned, in my ignorance, to do some fancy tests with the tilt function first. As I looked at the camera and lens set up on the macro stand I changed my mind and tried out a shift shot first. I was thrilled with the result. At 15mm full shift I got a completely different view of the coin( no lighting change no focus change) Here is the comparison( both at F8 left image normal position right image 15mm shift)  Some people may not know what I mean by shift. What amazed me was I was able to get the coin almost completely out from under the lens( I had no idea this was possible):   Check the view in the LCD screen you can see the coins image is centred in the middle of the sensor. I then tried a tilt shot not to get a good picture but rather to see how the depth-of-field changed( the coin ended up slicing through the depth of field. First picture shows the change in DOF second shot shows the tilt:   Now with this first set of tests I learnt shift was going to be more useful as there was much less mucking around. With tilt I would have to place the coin on some form of angled support and then adjust the tilt to match....and that would only result in the same as a shift shot. One might say I should have just gone for the shift adapter(US$400.00) However as I said earlier I want to have a wide angle tilt shift option for outdoors photography. The Mamiya 80mm is a 1-2 macro. I have the 1-1 adapter( extension tube) s I tried it out and here I saw the first real limitations of the system. This shot looks good ( 15mm shift) the coin is only 16mm in diameter:  Although it looks good theres a BUT!. The mamiya 645 lens produces a 75+mm image circle which is huge but with the 1-1 adapter it almost isn't big enough as the unedited picture shows:  I am really happy with the adapter and new mamiya 80mm macro lens. However it won't be for every one. Its best for a full frame camera and silver dollar sized coins. I could have got a cheaper adapter: but The Mirex adapter is a very well designed beautifully engineered product: you get what you pay for! Over the next few days I will try it out further and post later impressions. Edit I forgot to add in: using the shift the Chromatic aberration problem figuratively faded away! Edited by austrokiwi
11/06/2014 11:32 am
|
|
|
|
CCF Sponsor
United States
702 Posts |
I have always wanted to try T/S with coins! Thanks for sharing the results.
Could just be me, but from the small images provided, 5.6 looks sharpest to me. I see you allowed the shutterspeed or ISO (or both?) to compensate for the aperture setting as they all appear to have the same relative luminance. Is that correct?
There appears to be glare or lens flare of a bluish hue on the NZ coin. Is this the effect of the shift? It looks slightly less sharp at 4 o'clock than at 10 o'clock, I assume this is the shift working. The effect here isn't pronounced enough to offer contrast, but it is interesting to see.
Thanks again for sharing!
|
|
Pillar of the Community
 United States
4038 Posts |
With that very premium T/S adapter you can combine a little tilt with a little shift and get benefit from both while keeping the center of the coin in center of the image circle.
Contact me for photographic equipment or visit my home page at: http://macrocoins.com |
|
Pillar of the Community
 2087 Posts |
Quote:
Could just be me, but from the small images provided, 5.6 looks sharpest to me. I see you allowed the shutterspeed or ISO (or both?) to compensate for the aperture setting as they all appear to have the same relative luminance. Is that correct? Thanks for the observation on the F value. even with the full sized shots there was very little difference from wide open to completely shut down. F 5.6 and F8 were the best I picked F8 as the best but I think you are right and its actually F5.6. For the test shots I used Aperture setting on the camera so you got that spot on. I did use an EV compensation setting of +1 but I don't think even that was enough ( theres going to have to be a lot more playing around to work out what works best) Quote:
There appears to be glare or lens flare of a bluish hue on the NZ coin. Is this the effect of the shift? It looks slightly less sharp at 4 o'clock than at 10 o'clock, I assume this is the shift working. The effect here isn't pronounced enough to offer contrast, but it is interesting to see. To my eyes the whole left side of that 3 pence image is soft. I think the bluish hue is as you say due to the extreme shift. That said the coin is very close to real life colour( its cupronickel). I have started out using the extreme settings as that way I will know what the limits are. I also think I should do another F stop test at full shift to see if another F stop is better. The mirex offers more shift and tilt than nearly all dedicated Tilt shift lenses. It can do that because its using lenses that project huge image circles. I had read one reviewer complaining that the mirex didn't use the full potential of the lenses. I suspect, don't know, the makers of the adapter, developed it to be compatible with the whole range of medium format lenses that are appropriate for tilt shift. So with this 80mm macro the 15mm shift is almost too much but on a 35mm wide angle it probably isn't as much as it could be. The 35mm N I purchased is due to arrive in the next few days I will be able to test that theory out then. rmpsrmps is more than likely correct( I need to try it out to confirm): Smaller amounts of tilt and shift will work better. However, at the moment I am finding it difficult envisaging tilt as being useful for anything other than artistic shots of coins. Any suggestions on tests I should make( they help my learning) would be appreciated. I have been trying some other shots( with shift) on my least photogenic coins.....and I am finding the shift is solving a lot of previously, for me, unsolvable issues. This I did not suspect: that shift would be the most useful. {Its early days so I may end up reversing this opinion} Does anyone want pictures of the adapter? Edited by austrokiwi
11/07/2014 01:12 am
|
|
Pillar of the Community
2087 Posts |
Scropper ++> you were more right than I realised the bluish hue/tinge was lens flare. Lesson learned this particular lens hates back lighting. I was doing some more testing and I was getting this horrible washed out look( with a blue tinge) I turned off the back light and it was gone. 10mm shift at F11 seems to be producing the best results with my undiffused lighting set up. This shot impressed me. the coin has 234 years of toning plus some cabinet rubbing on the high points. This picture is the best I have taken (true color wise). In real life this coin is a pain to examine as the toning and weak strike combine to hide details ( I think there is even tabacco smoke staining on it)  Edited by austrokiwi
11/07/2014 05:46 am
|
|
Valued Member
440 Posts |
What is the benefit of using this type of equipment vs. just tilting the coin?
|
|
Pillar of the Community
2087 Posts |
Accuracy is one of the key benefits. You know that joke about some looking for a lost contact lens in the living room and some helping asks " where did you loose it? the punch line goes It was lost in the bedroom but they are looking in the living room because the light is better. The shift function allows you to "find the contact lens in the bedroom while looking in the living room". What I mean: you can move the coin into a much better position for lighting while being able to keep the coin and the camera sensor parallel. Tilting the coin produces distortion unless you can move the sensor so that it is parallel to the coin. I haven't played with the tilt function( with coins) but that is the key advantage of tilt( for coins). You can tilt the coin and then adjust the tilt of the lens so that the field of focus and sensor line up with the coin. As I said earlier in the thread what I hadn't realised was the shift function does that same job but in a much simpler way. The issue is simplicity : For me the shift function just means I ensure the camera is level and the copy stand base board is level. I then shift the lens to the best position and place the coin. I don't have to do anything else. In out doors photography Tilt allows you to adjust for parallax distortion and shift allows for impressive panoramas Edit heres a test Panorama I did to day( its three pictures (1 with left shift, 1 fully centered, 1 with right shift) stitched together in Adobe elements. My camera has a panorama function but there is no way it can come close to this(this pictures normal size is 38.7 inches by 14 inches)  Edited by austrokiwi
11/07/2014 10:25 am
|
|
CCF Sponsor
United States
702 Posts |
CherreePicker - the thing that has always intrigued me about T/S is the ability to change the focal plane WITHOUT tilting the subject. In this manner, you can get a very interesting depth of field you can't get anywhere else.
Notice Pic number six of the large Liberty reverse coin in OP's post? The coin is flat, but the DOF is not. Very cool!
austrokiwi - the effect of not moving the coin but being able to change the lighting is one I simply hadn't considered. Brilliant!
And the image of the dark coin is fantastic, so well done!
|
|
Pillar of the Community
2087 Posts |
Yeah I was pleased with that toned Thaler picture.... Now I have done more testing and reading. I had been religiously following the standard instructions for using tilt shift lenses and then I realised I didn't need to. The standard instructions are exposure etc should all be set before operating any of the tilt shift functions. The reason being ( please someone correct me if I have it wrong) with the change in perspective the DSLR mirror doesn't allow for accurate metering and view of the subject through the view finder or rear screen. Thats because of the mirror: I am using a mirrorless camera: so I can make all the tilt shift adjustments adjustments and then set the exposure etc.
The other thing I learnt the 80mm mamiya is OK but its not really the best. I have been playing with a more modern 35mm N lens. Its clear the "N" has much better flare resistance and much better colour rendition. If any one was to do the same get the "N" version. I also think the 80mm just doesn't have enough "reach". There is a much more sought after 120mm macro its more expensive but I think in a few months I will be replacing the 80mm with the 120mm.
Edited by austrokiwi
11/08/2014 4:02 pm
|
|
Valued Member
440 Posts |
austowiki & Scropper thank you for taking the time to provide detailed explanations. Makes much more sense; especially like the idea of adapting this to landscape & wildlife photography. You have given me some ideas.
|
|
Pillar of the Community
United States
9792 Posts |
I will have to give this a try soon, my roommate just picked up a 24mm Canon T/S lens in version 2. Would be great for shooting those coins in slabs that are not level in them.
"Buy the Book Before You Buy the Coin" - Aaron R. Feldman - "And read it" - Me 2013! ANA Life Member #3288 in good standing since 1981, ANS, Early American Coppers Member (EAC), Colonial Coin Collectors Club member (C4), Conder Token Collector Club member (CTCC), Civil War Token Society (CWTS) member, Liberty Seated Collectors Club (LSCC) & Numismatic Bibliomania Society member (NBS), USMex, Member in good standing, 2¢ variety collector. See my want page: http://goccf.com/t/140440 |
|
Bedrock of the Community
United States
10045 Posts |
I've always wanted to play with tilt-shift...someday I'll get one of those lenses.  Nice setup!  What's the purpose of the illuminated base--to get a white background?  At least on my setup, that would affect the exposure and possibly image contrast with stray light entering the lens... |
|
Pillar of the Community
2087 Posts |
Quote:
What's the purpose of the illuminated base--to get a white background? Thats how it started out.... I don't often get flare with it( I set white balance when its on) but with the Mamiya lenses its definitely a no go! I have also used it for one form of lighting.....I used Aluminium foil ( extremely crumpled) to make a dome then I turn the back light on and use it as the sole lighting source...with some coins its Brilliant on others its a flop! I have been using it less and less since starting to use the Mamiya! |
|
CCF Sponsor
United States
702 Posts |
Quote:
I used Aluminium foil ( extremely crumpled) to make a dome then I turn the back light on and use it as the sole lighting source That's an interesting idea! How do you keep from scratching the surface of the slide viewer. (I assume it's a slide viewer...) It's my experience those things scratch very easily and with metal on and off of them all the time, it'd be easy for it to get ugly quick! |
|
Pillar of the Community
2087 Posts |
Quote:
(I assume it's a slide viewer...) Its a cheap Chinese backlight The surface is some sort of acrylic |
| |
Replies: 14 / Views: 3,577 |
|
Posted 11/06/2014 11:19 am
